Which NCERT Biology lines has NEET asked about more than once?

79 of the 348 lines on this page were tested by two or more questions. The most tested: Population interactions (NCERT Class 12 Biology, Ch. 11, p. 197; 5 questions, 2021, 2022, 2023, 2025); Productivity, decomposition, energy flow (NCERT Class 12 Biology, Ch. 12, p. 207; 4 questions, 2020, 2023, 2024, 2025); Conservation (NCERT Class 12 Biology, Ch. 13, p. 224; 4 questions, 2022, 2024, 2025); Evil Quartet: four causes of biodiversity loss (NCERT Class 12 Biology, Ch. 13, p. 222; 4 questions, 2022, 2023, 2024, 2025); Immunity (NCERT Class 12 Biology, Ch. 7, p. 134; 4 questions, 2020, 2022, 2024, 2025).

How were these NCERT lines chosen?

Each line is an NCERT Biology passage that a NEET question from 2020 to 2025 was matched to directly: the question can be answered from that line. 348 lines across 36 chapters, tied to 361 questions. The count covers the questions matched to our NCERT extract, which does not yet hold every page of the book, so a line missing here may still have been tested.

Which page numbers are these?

The page number printed in the NCERT book, not the page of a PDF file. Chapters are numbered as the current (2023 rationalised) edition prints them; a chapter that edition dropped is marked pre-2023 edition.

Which NCERT Biology chapter has the most lines NEET tested?

Molecular Basis of Inheritance (Class 12, Chapter 5): 25 lines, tied to 31 questions.

NCERT line-by-line Biology for NEET: the lines NEET tested

Reading NCERT line by line works best when you know which lines NEET turns into questions. This page lists 348 NCERT Biology lines across 36 chapters that NEET questions from 2020 to 2025 were answered from, 361 questions in all. Each line gives the page printed in your NCERT book, the years and question numbers that tested it, and the lesson that teaches it.

Quotation marks mean NCERT's own words, checked against the book's page text and cut to a single line; open your copy at the page for the full passage. Where a line has no quotation, the text is our summary. A question is matched to a line only when the line alone answers it, and only questions you can solve on this site are listed.

Each chapter opens with its topic index: the PrepBrix lessons on that chapter in NCERT page order, each with the first printed page it cites and its count of past NEET questions.

Class 11, Chapter 1: The Living World

Printed pages 1–9. 2 lines tested by 2 questions.

Topics in this chapter (1), in NCERT order

Biodiversity Nomenclaturep. 34 PYQs

Biodiversity
In short: Biodiversity is the number and types of organisms present on Earth
NCERT Class 11 Biology, Ch. 1, p. 3, section 1.2
Tested in: NEET 2020 Q104
Learn it: Biodiversity Patterns · Biodiversity Nomenclature
Taxonomic categories
In short: The taxonomic hierarchy: Kingdom > Phylum (Division for plants) > Class > Order > Family > Genus > Species
NCERT Class 11 Biology, Ch. 1, p. 8, section 1.3
Tested in: NEET 2022 Q177
Learn it: Biodiversity Nomenclature

Class 11, Chapter 2: Biological Classification

Printed pages 10–22. 8 lines tested by 7 questions.

Topics in this chapter (5), in NCERT order

Five Kingdomp. 111 PYQ
Monerap. 124 PYQs
Protistap. 140 PYQs
Fungip. 165 PYQs
Viruses Viroids Lichensp. 193 PYQs

Body organisation across the five kingdoms (Table 2.1)
In short: Table 2.1 gives body organisation as: Monera - Cellular
NCERT Class 11 Biology, Ch. 2, p. 11, section 2.0
Tested in: NEET 2025 Q153
Learn it: Five Kingdom
Cyanobacteria are autotrophic Monerans
“The cyanobacteria (also referred to as blue-green algae) have chlorophyll a similar to green plants and are photosynthetic autotrophs”
NCERT Class 11 Biology, Ch. 2, p. 13, section 2.1.2
Tested in: NEET 2022 Q200
Learn it: Monera
Yeast used to make bread and beer
“Some unicellular fungi, e.g., yeast are used to make bread and beer”
NCERT Class 11 Biology, Ch. 2, p. 16, section 2.3
Tested in: NEET 2025 Q158
Learn it: Microbes Household Industrial
Criteria for classifying fungi into classes
“The morphology of the mycelium, mode of spore formation and fruiting bodies form the basis for the division of the kingdom into various classes”
NCERT Class 11 Biology, Ch. 2, p. 17, section 2.3
Tested in: NEET 2024 Q119
Learn it: Fungi
Fungal sexual cycle: plasmogamy, karyogamy, meiosis
“The sexual cycle involves the following three steps: (i) Fusion of protoplasms between two motile or non-motile gametes called plasmogamy. (ii) Fusion of two nuclei called karyogamy. (iii) Meiosis in zygote resulting in haploid spores”
NCERT Class 11 Biology, Ch. 2, p. 17, section 2.3
Tested in: NEET 2021 Q142
Learn it: Fungi
Rhizopus is a Phycomycete (bread mould)
“Some common examples are Mucor (Figure 2.5a), Rhizopus (the bread mould mentioned earlier) and Albugo (the parasitic fungi on mustard)”
NCERT Class 11 Biology, Ch. 2, p. 17, section 2.3.1
Tested in: NEET 2024 Q107
Learn it: Fungi
Ascomycetes (Penicillium) form conidia asexually
“Commonly known as sac-fungi, the ascomycetes are mostly multicellular, e.g., Penicillium, or rarely unicellular, e.g., yeast”
NCERT Class 11 Biology, Ch. 2, p. 17, section 2.3.2
Tested in: NEET 2022 Q155
Learn it: Fungi
Agaricus, Ustilago, Puccinia are Basidiomycetes
“Some common members are Agaricus (mushroom) (Figure 2.5c), Ustilago (smut) and Puccinia (rust fungus)”
NCERT Class 11 Biology, Ch. 2, p. 18, section 2.3.3
Tested in: NEET 2024 Q107
Learn it: Fungi

Class 11, Chapter 3: Plant Kingdom

Printed pages 23–36. 11 lines tested by 12 questions.

Topics in this chapter (4), in NCERT order

Plant Kingdom Algaep. 244 PYQs
Plant Kingdomp. 264 PYQs
Plant Kingdom Bryophytes Pteridophytesp. 299 PYQs
Plant Kingdom Gymnospermsp. 323 PYQs

Hydrocolloids: algin (brown), carrageen (red)
“Certain marine brown and red algae produce large amounts of hydrocolloids (water holding substances), e.g., algin (brown algae) and carrageen (red algae) which are used commercially”
NCERT Class 11 Biology, Ch. 3, p. 26, section 3.1
Tested in: NEET 2022 Q104
Learn it: Plant Kingdom Algae · Plant Kingdom
Phaeophyceae: reproduction, pigments, cell wall
“They possess chlorophyll a, c, carotenoids and xanthophylls”
NCERT Class 11 Biology, Ch. 3, p. 27, section 3.1.2
Tested in: NEET 2024 Q142
Learn it: Plant Kingdom Algae · Plant Kingdom
Bryophytes
In short: Bryophytes are 'amphibians of the plant kingdom' — gametophyte dominant
NCERT Class 11 Biology, Ch. 3, p. 29, section 3.2
Tested in: NEET 2023 Q106
Learn it: Plant Kingdom Bryophytes Pteridophytes · Plant Kingdom
Bryophyte life cycle sequence
“…attached to the substratum by unicellular or multicellular rhizoids”
NCERT Class 11 Biology, Ch. 3, p. 29, section 3.2
Tested in: NEET 2025 Q154
Learn it: Plant Kingdom Bryophytes Pteridophytes · Plant Kingdom
Liverwort gemmae: asexual reproduction
Tested 2 times
“Asexual reproduction in liverworts takes place by fragmentation of thalli, or by the formation of specialised structures called gemmae (sing. gemma)”
NCERT Class 11 Biology, Ch. 3, p. 29, section 3.2.1
Tested in: NEET 2025 Q102, NEET 2021 Q120
Learn it: Plant Kingdom Bryophytes Pteridophytes · Plant Kingdom
Strobili or cones in pteridophytes
“In some cases sporophylls may form distinct compact structures called strobili or cones (Selaginella, Equisetum)”
NCERT Class 11 Biology, Ch. 3, p. 30, section 3.3
Tested in: NEET 2020 Q118
Learn it: Plant Kingdom Bryophytes Pteridophytes · Plant Kingdom
Pteridophyte spores form by meiosis
“The sporangia produce spores by meiosis in spore mother cells”
NCERT Class 11 Biology, Ch. 3, p. 30, section 3.3
Tested in: NEET 2025 Q141
Learn it: Plant Kingdom Bryophytes Pteridophytes · Plant Kingdom
Heterosporous pteridophytes: Selaginella, Salvinia
Tested 2 times
“Genera like Selaginella and Salvinia which produce two kinds of spores, macro (large) and micro (small) spores, are known as heterosporous”
NCERT Class 11 Biology, Ch. 3, p. 32, section 3.3
Tested in: NEET 2023 Q112, NEET 2021 Q133
Learn it: Plant Kingdom Bryophytes Pteridophytes · Plant Kingdom
Pteridophyte prothallus and fertilisation
“…free-living, mostly photosynthetic thalloid gametophytes called prothallus. These gametophytes require cool, damp, shady places to grow”
NCERT Class 11 Biology, Ch. 3, p. 32, section 3.3
Tested in: NEET 2025 Q141
Learn it: Plant Kingdom Bryophytes Pteridophytes · Plant Kingdom
Gymnosperms
In short: Gymnosperms: naked seeds (no fruit)
NCERT Class 11 Biology, Ch. 3, p. 32, section 3.4
Tested in: NEET 2025 Q129
Learn it: Plant Kingdom Gymnosperms · Plant Kingdom
Gymnosperm pollen tube grows to archegonia
“The pollen grain is released from the microsporangium. They are carried in air currents and come in contact with the opening of the ovules”
NCERT Class 11 Biology, Ch. 3, p. 33, section 3.4
Tested in: NEET 2023 Q139
Learn it: Plant Kingdom Gymnosperms · Plant Kingdom

Class 11, Chapter 4: Animal Kingdom

Printed pages 37–54. 21 lines tested by 13 questions.

Topics in this chapter (2), in NCERT order

Animal Kingdom Nonchordatesp. 3710 PYQs
Animal Kingdom Chordatesp. 4712 PYQs

Coelenterates, ctenophores, echinoderms are radial
“…it is called radial symmetry. Coelenterates, ctenophores and echinoderms have this kind of body plan”
NCERT Class 11 Biology, Ch. 4, p. 38, section 4.1.2
Tested in: NEET 2023 Q175
Learn it: Animal Kingdom Nonchordates
Coelomate, pseudocoelomate, acoelomate defined
“Animals possessing coelom are called coelomates, e.g., annelids, molluscs, arthropods, echinoderms, hemichordates and chordates”
NCERT Class 11 Biology, Ch. 4, p. 39, section 4.1.4
Tested in: NEET 2025 Q176
Learn it: Animal Kingdom Nonchordates
Physalia is the Portuguese man-of-war
“Examples: Physalia (Portuguese man-of-war), Adamsia (Sea anemone), Pennatula (Sea-pen), Gorgonia (Sea-fan) and Meandrina (Brain coral)”
NCERT Class 11 Biology, Ch. 4, p. 41, section 4.2.2
Tested in: NEET 2021 Q156
Learn it: Animal Kingdom Nonchordates
Pleurobrachia is an example of Ctenophora
“Fertilisation is external with indirect development. Examples: Pleurobrachia and Ctenoplana”
NCERT Class 11 Biology, Ch. 4, p. 42, section 4.2.3
Tested in: NEET 2024 Q165
Learn it: Animal Kingdom Nonchordates
Ancylostoma is the hookworm (Aschelminthes)
“Examples : Ascaris (Roundworm), Wuchereria (Filaria worm), Ancylostoma (Hookworm)”
NCERT Class 11 Biology, Ch. 4, p. 43, section 4.2.5
Tested in: NEET 2021 Q156
Learn it: Animal Kingdom Nonchordates
Arthropoda
In short: Largest phylum
NCERT Class 11 Biology, Ch. 4, p. 44, section 4.2.6
Tested in: NEET 2022 Q134
Learn it: Animal Kingdom Nonchordates
Limulus (King crab) is a living fossil
“Gregarious pest – Locusta (Locust) Living fossil – Limulus (King crab)”
NCERT Class 11 Biology, Ch. 4, p. 44, section 4.2.7
Tested in: NEET 2021 Q156
Learn it: Animal Kingdom Nonchordates
Radula is Mollusca's rasping feeding organ
“The mouth contains a file-like rasping organ for feeding, called radula”
NCERT Class 11 Biology, Ch. 4, p. 44, section 4.2.8
Tested in: NEET 2024 Q165
Learn it: Animal Kingdom Nonchordates
Pinctada is the pearl oyster (Mollusca)
“Examples: Pila (Apple snail), Pinctada (Pearl oyster), Sepia”
NCERT Class 11 Biology, Ch. 4, p. 45, section 4.2.8
Tested in: NEET 2021 Q156
Learn it: Animal Kingdom Nonchordates
Water vascular system: locomotion, feeding, respiration
“The most distinctive feature of echinoderms is the presence of water vascular system which helps in locomotion, capture and transport of food and respiration”
NCERT Class 11 Biology, Ch. 4, p. 45, section 4.2.9
Tested in: NEET 2025 Q123
Learn it: Animal Kingdom Nonchordates
Hemichordates are bilaterally symmetrical
“They are bilaterally symmetrical, triploblastic and coelomate animals”
NCERT Class 11 Biology, Ch. 4, p. 45, section 4.2.10
Tested in: NEET 2023 Q175
Learn it: Animal Kingdom Nonchordates
Stomochord is Hemichordata's notochord-like structure
“Hemichordates have a rudimentary structure in the collar region called stomochord, a structure similar to notochord”
NCERT Class 11 Biology, Ch. 4, p. 45, section 4.2.10
Tested in: NEET 2024 Q165
Learn it: Animal Kingdom Nonchordates
Vertebrates are chordates; notochord replaced
Tested 2 times
“The notochord is replaced by a cartilaginous or bony vertebral column in the adult”
NCERT Class 11 Biology, Ch. 4, p. 46, section 4.2.11
Tested in: NEET 2025 Q93, NEET 2022 Q158
Learn it: Animal Kingdom Chordates
Chordates have closed circulation, gill slits
“They possess a post anal tail and a closed circulatory system”
NCERT Class 11 Biology, Ch. 4, p. 46, section 4.2.11
Tested in: NEET 2023 Q195
Learn it: Animal Kingdom Chordates
Table 4.1 chordate vs non-chordate features
In short: Chordates have notochord present, dorsal hollow single nerve cord, pharynx with gill slits, ventral heart, post-anal tail present
NCERT Class 11 Biology, Ch. 4, p. 46, section 4.2.11
Tested in: NEET 2024 Q188
Learn it: Animal Kingdom Chordates
Myxine (Hagfish) is a Cyclostomata example
“Their larvae, after metamorphosis, return to the ocean. Examples: Petromyzon (Lamprey) and Myxine (Hagfish)”
NCERT Class 11 Biology, Ch. 4, p. 47, section 4.2.11.1
Tested in: NEET 2024 Q183
Learn it: Animal Kingdom Chordates
All Cyclostomata are ectoparasites
“All living members of the class Cyclostomata are ectoparasites on some fishes”
NCERT Class 11 Biology, Ch. 4, p. 47, section 4.2.11.1
Tested in: NEET 2025 Q110
Learn it: Animal Kingdom Chordates
Pristis (Saw fish) is a Chondrichthyes example
“Examples: Scoliodon (Dog fish), Pristis (Saw fish), Carcharodon (Great white shark), Trygon (Sting ray)”
NCERT Class 11 Biology, Ch. 4, p. 48, section 4.2.11.2
Tested in: NEET 2024 Q183
Learn it: Animal Kingdom Chordates
Air bladder regulates buoyancy in Osteichthyes
“Skin is covered with cycloid/ctenoid scales. Air bladder is present which regulates buoyancy”
NCERT Class 11 Biology, Ch. 4, p. 48, section 4.2.11.3
Tested in: NEET 2024 Q165
Learn it: Animal Kingdom Nonchordates
Exocoetus, Pterophyllum are Osteichthyes examples
“Examples: Marine – Exocoetus (Flying fish), Hippocampus (Sea horse)”
NCERT Class 11 Biology, Ch. 4, p. 48, section 4.2.11.3
Tested in: NEET 2024 Q183
Learn it: Animal Kingdom Chordates
Mammary glands, hair, pinnae unique to mammals
“The most unique mammalian characteristic is the presence of milk producing glands (mammary glands)”
NCERT Class 11 Biology, Ch. 4, p. 50, section 4.2.11.7
Tested in: NEET 2023 Q196
Learn it: Animal Kingdom Chordates

Class 11, Chapter 5: Morphology of Flowering Plants

Printed pages 55–70. 11 lines tested by 11 questions.

Topics in this chapter (4), in NCERT order

Fibrous roots originate from stem base
“These roots originate from the base of the stem and constitute the fibrous root system, as seen in the wheat plant”
NCERT Class 11 Biology, Ch. 5, p. 58, section 5.1
Tested in: NEET 2020 Q110
Learn it: Morphology Root Stem · Morphology Flowering Plants
Flower is a modified shoot with floral meristem
“A flower is a modified shoot wherein the shoot apical meristem changes to floral meristem”
NCERT Class 11 Biology, Ch. 5, p. 61, section 5.4
Tested in: NEET 2023 Q145
Learn it: Morphology Flowering Plants
Zygomorphic flower examples
“When it can be divided into two similar halves only in one particular vertical plane, it is zygomorphic, e.g., pea, gulmohur, bean, Cassia”
NCERT Class 11 Biology, Ch. 5, p. 62, section 5.5
Tested in: NEET 2022 Q109
Learn it: Morphology Flowering Plants
Actinomorphic flower examples
“When a flower can be divided into two equal radial halves in any radial plane passing through the centre, it is said to be actinomorphic, e.g., mustard, datura, chilli”
NCERT Class 11 Biology, Ch. 5, p. 62, section 5.5
Tested in: NEET 2024 Q109
Learn it: Morphology Flowering Plants
Epigynous flowers have inferior ovary
“In epigynous flowers, the margin of thalamus grows upward enclosing the ovary completely and getting fused with it, the other parts of flower arise above the ovary. Hence, the ovary is said to be inferior as in flowers of guava and cucumber, and the ray florets of sunflower”
NCERT Class 11 Biology, Ch. 5, p. 63, section 5.5
Tested in: NEET 2020 Q105
Learn it: Morphology Flowering Plants
Perigynous flower: half inferior ovary
Tested 2 times
“If gynoecium is situated in the centre and other parts of the flower are located on the rim of the thalamus almost at the same level, it is called perigynous”
NCERT Class 11 Biology, Ch. 5, p. 63, section 5.5
Tested in: NEET 2024 Q138, NEET 2020 Q122
Learn it: Morphology Flowering Plants
Vexillary aestivation in pea and bean
“In pea and bean flowers, there are five petals, the largest (standard) overlaps the two lateral petals (wings) which in turn overlap the two smallest anterior petals (keel); this type of aestivation is known as vexillary or papilionaceous”
NCERT Class 11 Biology, Ch. 5, p. 64, section 5.5.1.2
Tested in: NEET 2022 Q125
Learn it: Families Fabaceae Solanaceae
Twisted aestivation: china rose, lady's finger, cotton
“If one margin of the appendage overlaps that of the next one and so on as in china rose, lady's finger and cotton, it is called twisted”
NCERT Class 11 Biology, Ch. 5, p. 64, section 5.5.1.2
Tested in: NEET 2024 Q138
Learn it: Morphology Flowering Plants
Stamen fusion types: mono/di/polyadelphous
Tested 3 times
“The stamens may be united into one bunch or one bundle (monoadelphous) as in china rose, or two bundles (diadelphous) as in pea, or into more than two bundles (polyadelphous) as in citrus”
NCERT Class 11 Biology, Ch. 5, p. 64, section 5.5.1.3
Tested in: NEET 2024 Q147, NEET 2022 Q125, NEET 2021 Q104
Learn it: Families Fabaceae Solanaceae · Morphology Flowering Plants
Axile placentation: china rose, tomato, lemon
“When the placenta is axial and the ovules are attached to it in a multilocular ovary, the placentaion is said to be axile, as in china rose, tomato and lemon”
NCERT Class 11 Biology, Ch. 5, p. 65, section 5.5.1.4
Tested in: NEET 2023 Q114
Learn it: Morphology Flowering Plants
Drupe fruit: mango and coconut
“In mango and coconut, the fruit is known as a drupe”
NCERT Class 11 Biology, Ch. 5, p. 65, section 5.6
Tested in: NEET 2024 Q138
Learn it: Morphology Flowering Plants

Class 11, Chapter 6: Anatomy of Flowering Plants

Printed pages 71–78. 5 lines tested by 3 questions.

Topics in this chapter (2), in NCERT order

Anatomy Dicot Monocotp. 763 PYQs
Anatomy Flowering Plantsp. 7711 PYQs

Radial vascular bundle arrangement in roots
“When xylem and phloem within a vascular bundle are arranged in an alternate manner along the different radii, the arrangement is called radial such as in roots”
NCERT Class 11 Biology, Ch. 6, p. 73, section 6.1.3
Tested in: NEET 2022 Q105
Learn it: Anatomy Dicot Monocot
Monocot root has polyarch xylem bundles
“…there are usually more than six (polyarch) xylem bundles in the monocot root”
NCERT Class 11 Biology, Ch. 6, p. 74, section 6.2.2
Tested in: NEET 2022 Q105
Learn it: Anatomy Dicot Monocot
Monocot stem: sclerenchymatous hypodermis, no phloem parenchyma
“The monocot stem has a sclerenchymatous hypodermis, a large number of scattered vascular bundles, each surrounded by a sclerenchymatous bundle sheath”
NCERT Class 11 Biology, Ch. 6, p. 76, section 6.2.4
Tested in: NEET 2025 Q145
Learn it: Anatomy Dicot Monocot
Dicot vs monocot stem (TS)
Tested 2 times
In short: Dicot stem: vascular bundles in a ring, conjoint, open (cambium present), endarch
NCERT Class 11 Biology, Ch. 6, p. 76, section 6.4
Tested in: NEET 2025 Q145, NEET 2022 Q105
Learn it: Anatomy Dicot Monocot
Flaccid bulliform cells curl monocot leaves inward
“When they are flaccid due to water stress, they make the leaves curl inwards to minimise water loss”
NCERT Class 11 Biology, Ch. 6, p. 77, section 6.2.6
Tested in: NEET 2024 Q130
Learn it: Anatomy Flowering Plants

Class 11, Chapter 7: Structural Organisation in Animals

Printed pages 79–84. 4 lines tested by 5 questions.

Topics in this chapter (2), in NCERT order

Animal Tissuesp. 805 PYQs
Frog Anatomyp. 8210 PYQs

Animal tissues
In short: Four basic tissues: epithelial (covering — squamous, cuboidal, columnar, ciliated, glandular), connective (loose, dense, specialised — bone, cartilage, blood, adipose), muscular (skeletal, smooth, cardiac), nervous (neurons + neuroglia)
NCERT Class 11 Biology, Ch. 7, p. 80, section 7.1
Tested in: NEET 2022 Q161
Learn it: Animal Tissues
Male frog copulatory pad on forelimb first digit
“Male frogs can be distinguished by the presence of sound producing vocal sacs and also a copulatory pad on the first digit of the fore limbs which are absent in female frogs”
NCERT Class 11 Biology, Ch. 7, p. 81, section 7.2.1
Tested in: NEET 2025 Q146
Learn it: Frog Anatomy
Frog respiration differs in water vs on land
“In water, skin acts as aquatic respiratory organ (cutaneous respiration)”
NCERT Class 11 Biology, Ch. 7, p. 82, section 7.2.2
Tested in: NEET 2025 Q130
Learn it: Frog Anatomy
Frog vena cava and portal systems
Tested 2 times
“It receives blood through the major veins called vena cava”
NCERT Class 11 Biology, Ch. 7, p. 82, section 7.2.2
Tested in: NEET 2025 Q134, NEET 2025 Q174
Learn it: Frog Anatomy

Class 11, Chapter 8: Cell — The Unit of Life

Printed pages 85–103. 17 lines tested by 16 questions.

Topics in this chapter (7), in NCERT order

Cell Theoryp. 882 PYQs
Prokaryotic vs Eukaryoticp. 913 PYQs
Cell Membrane Wallp. 932 PYQs
Cell Organelles Endomembranep. 956 PYQs
Cell Organelles Mitochondria Plastidp. 976 PYQs
Ribosomes Cytoskeleton Ciliap. 985 PYQs
Nucleus Chromosomesp. 1013 PYQs

Reductionist Biology (Unit 3 opener)
“This physico-chemical approach to study and understand living organisms is called ‘Reductionist Biology’”
NCERT Class 11 Biology, Ch. 8, p. 85, section 8.0
Tested in: NEET 2025 Q177
Learn it: Cell Theory
Prokaryotic vs eukaryotic
In short: Prokaryotes: no membrane-bound nucleus, smaller (1-10 μm), 70S ribosomes, no true organelles, single circular DNA, peptidoglycan cell wall (bacteria)
NCERT Class 11 Biology, Ch. 8, p. 91, section 8.3
Tested in: NEET 2022 Q151
Learn it: Cell Organelles Endomembrane · Prokaryotic vs Eukaryotic
Mesosome: functions in prokaryotic cell
“A special membranous structure is the mesosome which is formed by the extensions of plasma membrane into the cell. These extensions are in the form of vesicles, tubules and lamellae”
NCERT Class 11 Biology, Ch. 8, p. 91, section 8.4.1
Tested in: NEET 2025 Q172
Learn it: Monera
Inclusion bodies are unbound, free in cytoplasm
“Reserve material in prokaryotic cells are stored in the cytoplasm in the form of inclusion bodies”
NCERT Class 11 Biology, Ch. 8, p. 91, section 8.4.2
Tested in: NEET 2020 Q128
Learn it: Prokaryotic vs Eukaryotic
Cell Membrane composition
In short: The detailed structure of the cell membrane was studied only after the electron microscope arrived in the 1950s
NCERT Class 11 Biology, Ch. 8, p. 93, section 8.5.1
Tested in: NEET 2025 Q167
Learn it: Cell Membrane Wall
Active transport across the membrane
In short: A few ions or molecules are transported across the membrane against their concentration gradient, i.e., from lower to higher concentration
NCERT Class 11 Biology, Ch. 8, p. 94, section 8.5.1
Tested in: NEET 2023 Q103
Learn it: Cell Membrane Wall
Endomembrane system
In short: Connected membranes — ER (rough = ribosomes for protein synthesis
NCERT Class 11 Biology, Ch. 8, p. 95, section 8.5
Tested in: NEET 2023 Q166
Learn it: Cell Organelles Endomembrane
Golgi apparatus: cis-face intake, trans-face release
“The golgi apparatus principally performs the function of packaging materials, to be delivered either to the intra-cellular targets or secreted outside the cell”
NCERT Class 11 Biology, Ch. 8, p. 96, section 8.5.3.2
Tested in: NEET 2025 Q113
Learn it: Cell Organelles Endomembrane
Mitochondria and plastids
Tested 3 times
In short: Mitochondria: double membrane
NCERT Class 11 Biology, Ch. 8, p. 97, section 8.5.5
Tested in: NEET 2025 Q167, NEET 2024 Q129, NEET 2024 Q182
Learn it: Cell Membrane Wall · Cell Organelles Endomembrane
Chloroplast stroma has circular double-stranded DNA
“It also contains small, double-stranded circular DNA molecules and ribosomes”
NCERT Class 11 Biology, Ch. 8, p. 98, section 8.5.5
Tested in: NEET 2024 Q136
Learn it: Cell Organelles Mitochondria Plastid
Ribosomes
In short: Ribosomes are the granular structures first observed under the electron microscope as dense particles by George Palade (1953)
NCERT Class 11 Biology, Ch. 8, p. 98, section 8.5.6
Tested in: NEET 2025 Q152
Learn it: Ribosomes Cytoskeleton Cilia
Cytoskeleton
In short: An elaborate network of filamentous proteinaceous structures consisting of microtubules, microfilaments and intermediate filaments present in the cytoplasm is collectively referred to as the cytoskeleton
NCERT Class 11 Biology, Ch. 8, p. 98, section 8.5.7
Tested in: NEET 2023 Q163
Learn it: Ribosomes Cytoskeleton Cilia
Cilia and flagella: the 9+2 array
Tested 2 times
In short: Cilia and flagella are hair-like outgrowths of the cell membrane
NCERT Class 11 Biology, Ch. 8, p. 99, section 8.5.8
Tested in: NEET 2025 Q167, NEET 2024 Q182
Learn it: Ribosomes Cytoskeleton Cilia · Cell Membrane Wall
Centrosome and centrioles
Tested 2 times
In short: A centrosome is an organelle usually containing two cylindrical structures called centrioles
NCERT Class 11 Biology, Ch. 8, p. 99, section 8.5.9
Tested in: NEET 2024 Q129, NEET 2024 Q182
Learn it: Ribosomes Cytoskeleton Cilia · Cell Organelles Endomembrane
Nuclear pores, perinuclear space, enucleate cells
“…forms a barrier between the materials present inside the nucleus and that of the cytoplasm”
NCERT Class 11 Biology, Ch. 8, p. 100, section 8.5.10
Tested in: NEET 2021 Q110
Learn it: Nucleus Chromosomes
Nucleus and chromosomes
Tested 3 times
In short: Nucleus bounded by nuclear envelope with pores
NCERT Class 11 Biology, Ch. 8, p. 101, section 8.6
Tested in: NEET 2024 Q129, NEET 2022 Q149, NEET 2021 Q119
Learn it: Nucleus Chromosomes · Cell Organelles Endomembrane
Microbodies
In short: Many membrane bound minute vesicles called microbodies, that contain various enzymes, are present in both plant and animal cells
NCERT Class 11 Biology, Ch. 8, p. 102, section 8.5.11
Tested in: NEET 2021 Q110
Learn it: Nucleus Chromosomes · Ribosomes Cytoskeleton Cilia

Class 11, Chapter 9: Biomolecules

Printed pages 104–119. 13 lines tested by 13 questions.

Topics in this chapter (3), in NCERT order

Biomolecules Carbohydrates Lipidsp. 1086 PYQs
Biomolecules Proteins Nucleicp. 1125 PYQs
Enzymesp. 11611 PYQs

Nitrogen base, nucleoside, nucleotide, amino acid terms
“Some of these are nitrogen bases – adenine, guanine, cytosine, uracil, and thymine. When found attached to a sugar, they are called nucleosides”
NCERT Class 11 Biology, Ch. 9, p. 106, section 9.1
Tested in: NEET 2025 Q103
Learn it: Biomolecules Proteins Nucleic
Fatty acids, saturation, esters, phospholipids
Tested 2 times
“Fatty acids could be saturated (without double bond) or unsaturated (with one or more C=C double bonds)”
NCERT Class 11 Biology, Ch. 9, p. 106, section 9.1
Tested in: NEET 2024 Q101, NEET 2022 Q143
Learn it: Biomolecules Carbohydrates Lipids
Table 9.5: proteins and their functions
In short: Table 9.5 lists proteins with their functions: Collagen — intercellular ground substance
NCERT Class 11 Biology, Ch. 9, p. 109, section 9.4
Tested in: NEET 2024 Q144
Learn it: Enzymes · Biomolecules Proteins Nucleic
Starch-iodine blue colour vs cellulose
“Starch forms helical secondary structures. In fact, starch can hold I2 molecules in the helical portion. The starch-I2 is blue in colour. Cellulose does not contain complex helices and hence cannot hold I2”
NCERT Class 11 Biology, Ch. 9, p. 110, section 9.5
Tested in: NEET 2023 Q135
Learn it: Biomolecules Carbohydrates Lipids
Adult haemoglobin: 4 subunits, two alpha two beta
“Adult human haemoglobin consists of 4 subunits. Two of these are identical to each other. Hence, two subunits of α type and two subunits of β type together constitute the human haemoglobin (Hb)”
NCERT Class 11 Biology, Ch. 9, p. 112, section 9.7
Tested in: NEET 2023 Q160
Learn it: Biomolecules Proteins Nucleic
Catalytic cycle of enzyme action, in order
“First, the substrate binds to the active site of the enzyme, fitting into the active site”
NCERT Class 11 Biology, Ch. 9, p. 115, section 9.8.3
Tested in: NEET 2024 Q192
Learn it: Enzymes
Enzymes: activity, substrate saturation and competitive inhibition
Tested 2 times
In short: Almost all enzymes are proteins
NCERT Class 11 Biology, Ch. 9, p. 116, section 9.7
Tested in: NEET 2024 Q124, NEET 2023 Q176
Learn it: Enzymes
Temperature effect on enzyme activity
“Low temperature preserves the enzyme in a temporarily inactive state whereas high temperature destroys enzymatic activity because proteins are denatured by heat”
NCERT Class 11 Biology, Ch. 9, p. 116, section 9.8.4
Tested in: NEET 2023 Q176
Learn it: Enzymes
Competitive inhibitor: malonate on succinic dehydrogenase
Tested 2 times
“When the inhibitor closely resembles the substrate in its molecular structure and inhibits the activity of the enzyme, it is known as competitive inhibitor”
NCERT Class 11 Biology, Ch. 9, p. 117, section 9.8.4
Tested in: NEET 2024 Q124, NEET 2023 Q176
Learn it: Enzymes
Enzyme classes: transferases and hydrolases
“Transferases: Enzymes catalysing a transfer of a group, G (other than hydrogen) between a pair of substrate S and S”
NCERT Class 11 Biology, Ch. 9, p. 117, section 9.8.5
Tested in: NEET 2025 Q156
Learn it: Enzymes · Biomolecules Proteins Nucleic
Apoenzyme: protein portion of an enzyme
“In these instances, the protein portion of the enzymes is called the apoenzyme”
NCERT Class 11 Biology, Ch. 9, p. 118, section 9.8.6
Tested in: NEET 2025 Q116
Learn it: Enzymes
Zinc cofactor for carboxypeptidase
“A number of enzymes require metal ions for their activity which form coordination bonds with side chains at the active site”
NCERT Class 11 Biology, Ch. 9, p. 118, section 9.8.6
Tested in: NEET 2024 Q105
Learn it: Enzymes
Haem prosthetic group in catalase and peroxidase
“Prosthetic groups are organic compounds and are distinguished from other cofactors in that they are tightly bound to the apoenzyme”
NCERT Class 11 Biology, Ch. 9, p. 118, section 9.8.6
Tested in: NEET 2025 Q143
Learn it: Enzymes

Class 11, Chapter 10: Cell Cycle and Cell Division

Printed pages 120–130. 16 lines tested by 19 questions.

Topics in this chapter (3), in NCERT order

Cell Cycle Phasesp. 1216 PYQs
Mitosis Phasesp. 1224 PYQs
Meiosis Phasesp. 12610 PYQs

Cell cycle phases
In short: Interphase (~95%): G1 (cell growth), S (DNA replication, 2C → 4C), G2 (preparation for M)
NCERT Class 11 Biology, Ch. 10, p. 121, section 10.1
Tested in: NEET 2024 Q158
Learn it: Cell Cycle Phases
G1 and G2 phase definitions
“G1 phase corresponds to the interval between mitosis and initiation of DNA replication”
NCERT Class 11 Biology, Ch. 10, p. 121, section 10.1.1
Tested in: NEET 2023 Q149
Learn it: Cell Cycle Phases
S phase doubles DNA but not chromosome number
“…there is no increase in the chromosome number; if the cell had diploid or 2n number of chromosomes at G1, even after S phase the number of chromosomes remains the same, i.e., 2n”
NCERT Class 11 Biology, Ch. 10, p. 121, section 10.1.1
Tested in: NEET 2021 Q162
Learn it: Cell Cycle Phases
G0 cells stay metabolically active; centrosome duplicates in S phase
Tested 2 times
“Cells in this stage remain metabolically active but no longer proliferate unless called on to do so depending on the requirement of the organism”
NCERT Class 11 Biology, Ch. 10, p. 122, section 10.1.1
Tested in: NEET 2023 Q186, NEET 2021 Q182
Learn it: Cell Cycle Phases · Ribosomes Cytoskeleton Cilia
M phase is equational; G0 is an inactive stage
Tested 2 times
“Since the number of chromosomes in the parent and progeny cells is the same, it is also called as equational division”
NCERT Class 11 Biology, Ch. 10, p. 122, section 10.1.1/10.2
Tested in: NEET 2023 Q149, NEET 2020 Q95
Learn it: Cell Cycle Phases
Spindle fibres attach at kinetochores, not centromere
“Small disc-shaped structures at the surface of the centromeres are called kinetochores. These structures serve as the sites of attachment of spindle fibres to the chromosomes”
NCERT Class 11 Biology, Ch. 10, p. 123, section 10.2.2
Tested in: NEET 2022 Q181
Learn it: Mitosis Phases
Spindle fibres position and then separate chromosomes
Tested 3 times
“Spindle fibres attach to kinetochores of chromosomes. l Chromosomes are moved to spindle equator”
NCERT Class 11 Biology, Ch. 10, p. 123, section 10.2.2/10.2.3
Tested in: NEET 2025 Q96, NEET 2024 Q126, NEET 2023 Q189
Learn it: Mitosis Phases · Meiosis Phases
Telophase: nuclear envelope, nucleolus, golgi, ER reform
“Nuclear envelope develops around the chromosome clusters at each pole forming two daughter nuclei. l Nucleolus, golgi complex and ER reform”
NCERT Class 11 Biology, Ch. 10, p. 124, section 10.2.4
Tested in: NEET 2023 Q189
Learn it: Meiosis Phases
Chromosome pairing is a meiosis-only feature
Tested 2 times
“Meiosis involves pairing of homologous chromosomes and recombination between non-sister chromatids of homologous chromosomes”
NCERT Class 11 Biology, Ch. 10, p. 125, section 10.4
Tested in: NEET 2023 Q189, NEET 2022 Q103
Learn it: Mitosis Phases · Meiosis Phases
Meiosis: one DNA replication, two divisions
“Meiosis involves two sequential cycles of nuclear and cell division called meiosis I and meiosis II but only a single cycle of DNA replication”
NCERT Class 11 Biology, Ch. 10, p. 125, section 10.4
Tested in: NEET 2022 Q152
Learn it: Meiosis Phases
Recombination nodules appear at pachytene
Tested 3 times
“This stage is characterised by the appearance of recombination nodules, the sites at which crossing over occurs between non-sister chromatids of the homologous chromosomes”
NCERT Class 11 Biology, Ch. 10, p. 126, section 10.4.1
Tested in: NEET 2024 Q166, NEET 2023 Q119, NEET 2022 Q108
Learn it: Meiosis Phases
Diplotene: dissolution of synaptonemal complex
Tested 2 times
“The beginning of diplotene is recognised by the dissolution of the synaptonemal complex and the tendency of the recombined homologous chromosomes of the bivalents to separate from each other except at the sites of crossovers”
NCERT Class 11 Biology, Ch. 10, p. 126, section 10.4.1
Tested in: NEET 2024 Q128, NEET 2020 Q125
Learn it: Meiosis Phases
Diakinesis: terminalisation of chiasmata
Tested 3 times
“The final stage of meiotic prophase I is diakinesis. This is marked by terminalisation of chiasmata”
NCERT Class 11 Biology, Ch. 10, p. 126, section 10.4.1
Tested in: NEET 2024 Q166, NEET 2023 Q189, NEET 2021 Q154
Learn it: Meiosis Phases
Leptotene visibility; zygotene synapsis/synaptonemal complex
Tested 2 times
“…the chromosomes become gradually visible under the light microscope. The compaction of chromosomes continues throughout leptotene”
NCERT Class 11 Biology, Ch. 10, p. 126, section 10.4.1
Tested in: NEET 2024 Q128, NEET 2024 Q166
Learn it: Meiosis Phases
Tetrads become distinct at pachytene, not leptotene
“…the four chromatids of each bivalent chromosomes becomes distinct and clearly appear as tetrads”
NCERT Class 11 Biology, Ch. 10, p. 126, section 10.4.1
Tested in: NEET 2023 Q189
Learn it: Meiosis Phases
Anaphase II, not Anaphase I, splits the centromere
“The homologous chromosomes separate, while sister chromatids remain associated at their centromeres”
NCERT Class 11 Biology, Ch. 10, p. 127, section 10.4.1/10.4.2
Tested in: NEET 2023 Q133
Learn it: Meiosis Phases

Class 11, Chapter 11: Photosynthesis in Higher Plants

Printed pages 131–152. 9 lines tested by 10 questions.

Topics in this chapter (4), in NCERT order

Photosynthesis Chloroplastp. 1373 PYQs
Photosynthesis Light Reactionsp. 1393 PYQs
Photosynthesis C3 C4 CAMp. 14610 PYQs
Photosynthesis Factorsp. 1490 PYQs

Colours of the four leaf pigments
“…not due to a single pigment but due to four pigments: Chlorophyll a (bright or blue green in the chromatogram), chlorophyll b (yellow green), xanthophylls (yellow) and carotenoids (yellow to yellow-orange)”
NCERT Class 11 Biology, Ch. 11, p. 137, section 11.4
Tested in: NEET 2025 Q164
Learn it: Photosynthesis Chloroplast
Chloroplast and pigments
In short: Chloroplast: outer + inner membrane
NCERT Class 11 Biology, Ch. 11, p. 137, section 13.3
Tested in: NEET 2023 Q116
Learn it: Photosynthesis Light Reactions · Photosynthesis Chloroplast
Light reactions — Z-scheme
In short: PS II (P680) → e⁻ → PQ → cyt b6f → PC → PS I (P700) → ferredoxin → NADPH
NCERT Class 11 Biology, Ch. 11, p. 139, section 13.4
Tested in: NEET 2023 Q124
Learn it: Photosynthesis Light Reactions
Chemiosmosis: proton gradient breakdown makes ATP
“This gradient is important because it is the breakdown of this gradient that leads to the synthesis of ATP”
NCERT Class 11 Biology, Ch. 11, p. 141, section 11.6.3
Tested in: NEET 2022 Q119
Learn it: Photosynthesis Light Reactions
Biosynthetic (dark) phase needs CO2, ATP, NADPH
“This process does not directly depend on the presence of light but is dependent on the products of the light reaction, i.e., ATP and NADPH, besides CO2 and H2O”
NCERT Class 11 Biology, Ch. 11, p. 142, section 11.7
Tested in: NEET 2024 Q134
Learn it: Photosynthesis Chloroplast
ATP and NADPH required per CO2 fixed
“Hence for every CO2 molecule entering the Calvin cycle, 3 molecules of ATP and 2 of NADPH are required”
NCERT Class 11 Biology, Ch. 11, p. 145, section 11.7.2
Tested in: NEET 2024 Q102
Learn it: Photosynthesis C3 C4 CAM
ATP/NADPH to make one glucose in Calvin cycle
“To make one molecule of glucose 6 turns of the cycle are required”
NCERT Class 11 Biology, Ch. 11, p. 145, section 11.7.2
Tested in: NEET 2023 Q120
Learn it: Photosynthesis C3 C4 CAM
C3, C4, CAM
Tested 2 times
In short: C3: CO2 fixed by RuBisCO → 3PGA (3-C)
NCERT Class 11 Biology, Ch. 11, p. 146, section 13.7
Tested in: NEET 2025 Q114, NEET 2021 Q103
Learn it: Photosynthesis C3 C4 CAM
Photorespiration present in C3, absent in C4
“In C3 plants some O2 does bind to RuBisCO, and hence CO2 fixation is decreased”
NCERT Class 11 Biology, Ch. 11, p. 147, section 11.9
Tested in: NEET 2024 Q146
Learn it: Photosynthesis C3 C4 CAM

Class 11, Chapter 12: Respiration in Plants

Printed pages 153–165. 8 lines tested by 8 questions.

Topics in this chapter (3), in NCERT order

Glycolysis is the EMP pathway
“The scheme of glycolysis was given by Gustav Embden, Otto Meyerhof, and J. Parnas, and is often referred to as the EMP pathway”
NCERT Class 11 Biology, Ch. 12, p. 155, section 12.2
Tested in: NEET 2023 Q136
Learn it: Respiration Krebs ETC
Two ATP-utilising steps in glycolysis
“ATP is utilised at two steps: first in the conversion of glucose into glucose 6-phosphate”
NCERT Class 11 Biology, Ch. 12, p. 156, section 12.2
Tested in: NEET 2023 Q109
Learn it: Respiration Glycolysis
Glycolysis (EMP)
Tested 2 times
In short: Cytoplasm
NCERT Class 11 Biology, Ch. 12, p. 156, section 14.2
Tested in: NEET 2024 Q141, NEET 2022 Q129
Learn it: Respiration Glycolysis · Cell Organelles Mitochondria Plastid
Fermentation releases under 7% of glucose energy
“In both lactic acid and alcohol fermentation not much energy is released; less than seven per cent of the energy in glucose is released and not all of it is trapped as high energy bonds of ATP”
NCERT Class 11 Biology, Ch. 12, p. 157, section 12.3
Tested in: NEET 2022 Q127
Learn it: Respiration Fermentation
Pyruvate dehydrogenase catalyses oxidative decarboxylation
“…undergoes oxidative decarboxylation by a complex set of reactions catalysed by pyruvic dehydrogenase”
NCERT Class 11 Biology, Ch. 12, p. 158, section 12.4
Tested in: NEET 2023 Q136
Learn it: Respiration Krebs ETC
Citrate synthase forms citric acid in TCA cycle
“The TCA cycle starts with the condensation of acetyl group with oxaloacetic acid (OAA) and water to yield citric acid”
NCERT Class 11 Biology, Ch. 12, p. 158, section 12.4.1
Tested in: NEET 2023 Q136
Learn it: Respiration Krebs ETC
Krebs cycle (TCA) and ETC
Tested 3 times
In short: Krebs (mitochondrial matrix): 1 acetyl-CoA → 3 NADH + 1 FADH2 + 1 GTP + 2 CO2
NCERT Class 11 Biology, Ch. 12, p. 158, section 14.3
Tested in: NEET 2024 Q141, NEET 2023 Q137, NEET 2020 Q100
Learn it: Respiration Krebs ETC · Cell Organelles Mitochondria Plastid
ATP yield per NADH vs per FADH2 in ETC
“Oxidation of one molecule of NADH gives rise to 3 molecules of ATP, while that of one molecule of FADH2 produces 2 molecules of ATP”
NCERT Class 11 Biology, Ch. 12, p. 160, section 12.4.2
Tested in: NEET 2021 Q144
Learn it: Respiration Krebs ETC

Class 11, Chapter 13: Plant Growth and Development

Printed pages 166–180. 12 lines tested by 13 questions.

Topics in this chapter (2), in NCERT order

Plant Growth Phasesp. 1685 PYQs
Plant Hormonesp. 17412 PYQs

Plant growth
In short: Indeterminate growth — meristems retain capacity
NCERT Class 11 Biology, Ch. 13, p. 168, section 15.2
Tested in: NEET 2020 Q114
Learn it: Plant Growth Phases
Dedifferentiation precedes redifferentiation
Tested 2 times
“The living differentiated cells, that by now have lost the capacity to divide can regain the capacity of division under certain conditions. This phenomenon is termed as”
NCERT Class 11 Biology, Ch. 13, p. 172, section 13.2
Tested in: NEET 2025 Q126, NEET 2023 Q102
Learn it: Plant Hormones
Plasticity definition and examples (heterophylly)
Tested 2 times
“Plants follow different pathways in response to environment or phases of life to form different kinds of structures. This ability is called plasticity”
NCERT Class 11 Biology, Ch. 13, p. 173, section 13.3
Tested in: NEET 2022 Q114, NEET 2021 Q106
Learn it: Plant Growth Phases
PGRs: growth-promoting vs growth-inhibiting groups; ABA is an inhibitor
“One group of PGRs are involved in growth promoting activities, such as cell division, cell enlargement, pattern formation, tropic growth, flowering, fruiting and seed formation”
NCERT Class 11 Biology, Ch. 13, p. 174, section 13.4.1
Tested in: NEET 2025 Q126
Learn it: Plant Hormones
Plant hormones
Tested 3 times
In short: Auxin (IAA) — apical dominance, phototropism
NCERT Class 11 Biology, Ch. 13, p. 174, section 15.5
Tested in: NEET 2025 Q179, NEET 2024 Q150, NEET 2020 Q127
Learn it: Plant Hormones
Apical dominance: apical bud inhibits lateral bud growth
“…the growing apical bud inhibits the growth of the lateral (axillary) buds, a phenomenon called apical dominance”
NCERT Class 11 Biology, Ch. 13, p. 175, section 13.4.3.1
Tested in: NEET 2025 Q126
Learn it: Plant Hormones
2,4-D kills dicot weeds, spares mature monocots
“2, 4-D, widely used to kill dicotyledonous weeds, does not affect mature monocotyledonous plants. It is used to prepare weed-free lawns by gardeners”
NCERT Class 11 Biology, Ch. 13, p. 176, section 13.4.3.1
Tested in: NEET 2024 Q115
Learn it: Plant Hormones
Auxins induce parthenocarpy
“Auxins also induce parthenocarpy, e.g., in tomatoes. They are widely used as herbicides”
NCERT Class 11 Biology, Ch. 13, p. 176, section 13.4.3.1
Tested in: NEET 2025 Q126
Learn it: Plant Hormones
Gibberellins hasten conifer maturity for early seed production
“Spraying juvenile conifers with GAs hastens the maturity period, thus leading to early seed production”
NCERT Class 11 Biology, Ch. 13, p. 176, section 13.4.3.2
Tested in: NEET 2023 Q123
Learn it: Plant Hormones
Ethylene promotes female flowers in cucumber
“It promotes female flowers in cucumbers thereby increasing the yield”
NCERT Class 11 Biology, Ch. 13, p. 177, section 13.4.3.4
Tested in: NEET 2022 Q110
Learn it: Plant Hormones
Ethylene elongates internode/petiole in deep water rice
“Ethylene promotes rapid internode/petiole elongation in deep water rice plants”
NCERT Class 11 Biology, Ch. 13, p. 177, section 13.4.3.4
Tested in: NEET 2023 Q132
Learn it: Plant Hormones
Ethylene promotes root and root-hair growth
“Ethylene also promotes root growth and root hair formation, thus helping the plants to increase their absorption surface”
NCERT Class 11 Biology, Ch. 13, p. 177, section 13.4.3.4
Tested in: NEET 2022 Q124
Learn it: Plant Hormones

Class 11, Chapter 14: Breathing and Exchange of Gases

Printed pages 181–192. 6 lines tested by 6 questions.

Topics in this chapter (3), in NCERT order

Breathing Respiratory Organsp. 1832 PYQs
Breathing Mechanism Volumesp. 1863 PYQs
Breathing Gas Transportp. 1895 PYQs

Conducting part vs exchange part functions
“The conducting part transports the atmospheric air to the alveoli, clears it from foreign particles, humidifies and also brings the air to body temperature”
NCERT Class 11 Biology, Ch. 14, p. 185, section 14.1.1
Tested in: NEET 2022 Q176
Learn it: Breathing Respiratory Organs
Respiratory volumes
Tested 2 times
In short: TV (tidal volume) ~500 mL
NCERT Class 11 Biology, Ch. 14, p. 186, section 17.3
Tested in: NEET 2024 Q162, NEET 2023 Q165
Learn it: Breathing Mechanism Volumes
Partial pressures of O2 and CO2 at alveoli
In short: Table 14.1 gives partial pressures (mm Hg): in atmospheric air O2=159, CO2=0.3
NCERT Class 11 Biology, Ch. 14, p. 187, section 14.3
Tested in: NEET 2021 Q155
Learn it: Breathing Gas Transport
High pO2 and lesser H+ favour oxyhaemoglobin
“In the alveoli, where there is high pO2 , low pCO2 , lesser H+ concentration and lower temperature, the factors are all favourable for the formation of oxyhaemoglobin”
NCERT Class 11 Biology, Ch. 14, p. 189, section 14.4.1
Tested in: NEET 2024 Q176
Learn it: Breathing Gas Transport
O2 delivered per 100 ml oxygenated blood
“Every 100 ml of oxygenated blood can deliver around 5 ml of O2 to the tissues under normal physiological conditions”
NCERT Class 11 Biology, Ch. 14, p. 189, section 14.4.1
Tested in: NEET 2022 Q184
Learn it: Breathing Gas Transport
Gas transport
In short: O2 transport: about 97% of O2 is carried by haemoglobin in RBCs (each haemoglobin molecule carries a maximum of four O2 molecules)
NCERT Class 11 Biology, Ch. 14, p. 189, section 17.4
Tested in: NEET 2024 Q176
Learn it: Breathing Gas Transport

Class 11, Chapter 15: Body Fluids and Circulation

Printed pages 193–204. 8 lines tested by 7 questions.

Topics in this chapter (4), in NCERT order

Circulation Blood Lymphp. 1931 PYQ
Circulation Blood Groups Coagulationp. 1953 PYQs
Circulation Heart Cardiac Cyclep. 19910 PYQs
Circulation BP Disordersp. 2020 PYQs

Spleen is the graveyard of RBCs
“RBCs have an average life span of 120 days after which they are destroyed in the spleen (graveyard of RBCs)”
NCERT Class 11 Biology, Ch. 15, p. 194, section 15.1.2
Tested in: NEET 2022 Q153
Learn it: Circulation Blood Groups Coagulation
Basophils: granulocytes secreting histamine, heparin
“Neutrophils, eosinophils and basophils are different types of granulocytes, while lymphocytes and monocytes are the agranulocytes”
NCERT Class 11 Biology, Ch. 15, p. 194, section 15.1.2
Tested in: NEET 2023 Q192
Learn it: Circulation Blood Lymph
ABO Grouping
In short: ABO grouping is based on the presence or absence of two surface antigens (chemicals that can induce immune response) on RBCs, namely A and B
NCERT Class 11 Biology, Ch. 15, p. 195, section 15.1.3.1
Tested in: NEET 2021 Q161
Learn it: Circulation Blood Groups Coagulation
Coagulum is a network of fibrin threads
“It is a clot or coagulam formed mainly of a network of threads called fibrins in which dead and damaged formed elements of blood are trapped”
NCERT Class 11 Biology, Ch. 15, p. 196, section 15.1.4
Tested in: NEET 2022 Q153
Learn it: Circulation Blood Groups Coagulation
AV bundle divides into bundle branches, Purkinje fibres
“A bundle of nodal fibres, atrio-ventricular bundle (AV bundle) continues from the AVN which passes through the atrio-ventricular septa to emerge on the top of the inter-ventricular septum and immediately divides into a right and left bundle”
NCERT Class 11 Biology, Ch. 15, p. 199, section 15.3.1
Tested in: NEET 2024 Q151
Learn it: Circulation Heart Cardiac Cycle
Joint diastole: blood flows freely to ventricles
“As the tricuspid and bicuspid valves are open, blood from the pulmonary veins and vena cava flows into the left and the right ventricle”
NCERT Class 11 Biology, Ch. 15, p. 199, section 15.3.2
Tested in: NEET 2022 Q189
Learn it: Circulation Heart Cardiac Cycle
Heart and cardiac cycle
In short: Human heart: four-chambered (2 atria + 2 ventricles)
NCERT Class 11 Biology, Ch. 15, p. 199, section 18.3
Tested in: NEET 2024 Q198
Learn it: Circulation Heart Cardiac Cycle
Cardiac activity: nodal tissue, medulla, adrenal medulla
“Normal activities of the heart are regulated intrinsically, i.e., auto regulated by specialised muscles (nodal tissue), hence the heart is called myogenic”
NCERT Class 11 Biology, Ch. 15, p. 202, section 15.5
Tested in: NEET 2025 Q136
Learn it: Circulation Heart Cardiac Cycle

Class 11, Chapter 16: Excretory Products and their Elimination

Printed pages 205–216. 5 lines tested by 6 questions.

Topics in this chapter (3), in NCERT order

Excretion Kidney Nephronp. 2056 PYQs
Excretion Urine Formationp. 2091 PYQ
Excretion Regulation Disordersp. 2122 PYQs

Uricotelic animals excrete uric acid as pellet/paste
“Reptiles, birds, land snails and insects excrete nitrogenous wastes as uric acid in the form of pellet or paste with a minimum loss of water and are called uricotelic animals”
NCERT Class 11 Biology, Ch. 16, p. 205, section 19.1
Tested in: NEET 2022 Q156
Learn it: Excretion Kidney Nephron
Cortical vs juxtamedullary nephron loop length
Tested 2 times
“In majority of nephrons, the loop of Henle is too short and extends only very little into the medulla. Such nephrons are called cortical nephrons”
NCERT Class 11 Biology, Ch. 16, p. 208, section 19.1
Tested in: NEET 2024 Q189, NEET 2023 Q158
Learn it: Excretion Kidney Nephron
Henle's loop limb permeability to water vs electrolytes
“The descending limb of loop of Henle is permeable to water but almost impermeable to electrolytes. This concentrates the filtrate as it moves down”
NCERT Class 11 Biology, Ch. 16, p. 209, section 19.3
Tested in: NEET 2024 Q180
Learn it: Excretion Kidney Nephron
PCT lined by simple cuboidal brush border epithelium
“Proximal Convoluted Tubule (PCT): PCT is lined by simple cuboidal brush border epithelium which increases the surface area for reabsorption”
NCERT Class 11 Biology, Ch. 16, p. 209, section 19.3
Tested in: NEET 2024 Q180
Learn it: Excretion Kidney Nephron
Regulation and disorders
Tested 2 times
In short: ADH (vasopressin): water reabsorption in CD
NCERT Class 11 Biology, Ch. 16, p. 212, section 19.4
Tested in: NEET 2023 Q167, NEET 2023 Q193
Learn it: Excretion Regulation Disorders · Endocrine Adrenal Pancreas Gonads

Class 11, Chapter 17: Locomotion and Movement

Printed pages 217–229. 9 lines tested by 11 questions.

Topics in this chapter (2), in NCERT order

Locomotion Muscle Contractionp. 2184 PYQs
Locomotion Skeleton Joints Disordersp. 22411 PYQs

Muscle: Types by Location
Tested 2 times
In short: Muscle is a mesodermal tissue contributing about 40-50% of adult body weight, with properties of excitability, contractility, extensibility and elasticity
NCERT Class 11 Biology, Ch. 17, p. 218, section 17.2
Tested in: NEET 2024 Q173, NEET 2021 Q159
Learn it: Locomotion Muscle Contraction
Structure of the Muscle Fibre
In short: A skeletal muscle is made of muscle bundles (fascicles) held together by fascia, each fascicle containing many muscle fibres
NCERT Class 11 Biology, Ch. 17, p. 219, section 17.2
Tested in: NEET 2023 Q199
Learn it: Locomotion Muscle Contraction
The Sarcomere
In short: The light band of a myofibril contains actin and is called the I-band (Isotropic band)
NCERT Class 11 Biology, Ch. 17, p. 220, section 17.2
Tested in: NEET 2023 Q199
Learn it: Locomotion Muscle Contraction
Vertebral Column, Sternum and Ribs
In short: The vertebral column has 26 serially arranged vertebrae, extending from the base of the skull
NCERT Class 11 Biology, Ch. 17, p. 225, section 17.3
Tested in: NEET 2020 Q119
Learn it: Locomotion Skeleton Joints Disorders
Appendicular Skeleton: Limbs and Girdles
In short: The bones of the limbs with their girdles form the appendicular skeleton
NCERT Class 11 Biology, Ch. 17, p. 226, section 17.3
Tested in: NEET 2020 Q119
Learn it: Locomotion Skeleton Joints Disorders
Scapula is a triangular flat bone
“Scapula is a large triangular flat bone situated in the dorsal part of the thorax between the second and the seventh ribs”
NCERT Class 11 Biology, Ch. 17, p. 226, section 17.3
Tested in: NEET 2021 Q191
Learn it: Locomotion Skeleton Joints Disorders
Joints
Tested 3 times
In short: Joints are points of contact between bones, or between bones and cartilages
NCERT Class 11 Biology, Ch. 17, p. 227, section 17.4
Tested in: NEET 2024 Q184, NEET 2023 Q182, NEET 2022 Q157
Learn it: Locomotion Skeleton Joints Disorders
Cranium formed by fibrous joints (sutures)
“Fibrous joints do not allow any movement. This type of joint is shown by the flat skull bones which fuse end-to-end with the help of dense fibrous connective tissues in the form of sutures, to form the cranium”
NCERT Class 11 Biology, Ch. 17, p. 227, section 17.4
Tested in: NEET 2021 Q191
Learn it: Locomotion Skeleton Joints Disorders
Disorders of Muscular and Skeletal System
Tested 3 times
In short: Myasthenia gravis is an autoimmune disorder affecting the neuromuscular junction, leading to fatigue, weakening and paralysis of skeletal muscle
NCERT Class 11 Biology, Ch. 17, p. 227, section 17.5
Tested in: NEET 2022 Q162, NEET 2022 Q182, NEET 2021 Q160
Learn it: Locomotion Skeleton Joints Disorders

Class 11, Chapter 18: Neural Control and Coordination

Printed pages 230–238. 4 lines tested by 4 questions.

Topics in this chapter (2), in NCERT order

Neural Human Nervous Systemp. 2314 PYQs
Neural Neuron Impulse Synapsep. 2321 PYQ

Types of Synapses
In short: A nerve impulse passes from one neuron to another through junctions called synapses
NCERT Class 11 Biology, Ch. 18, p. 234, section 18.3.2
Tested in: NEET 2022 Q194
Learn it: Neural Neuron Impulse Synapse
Forebrain
In short: The forebrain consists of the cerebrum, thalamus and hypothalamus
NCERT Class 11 Biology, Ch. 18, p. 236, section 18.4.1
Tested in: NEET 2024 Q190
Learn it: Neural Human Nervous System
Limbic system, hypothalamus regulate emotions
“Along with the hypothalamus, it is involved in the regulation of sexual behaviour, expression of emotional reactions (e.g., excitement, pleasure, rage and fear), and motivation”
NCERT Class 11 Biology, Ch. 18, p. 236, section 18.4.1
Tested in: NEET 2023 Q197
Learn it: Neural Human Nervous System
Hindbrain
Tested 2 times
In short: The hindbrain comprises pons, cerebellum and medulla (also called the medulla oblongata)
NCERT Class 11 Biology, Ch. 18, p. 236, section 18.4.3
Tested in: NEET 2024 Q170, NEET 2024 Q190
Learn it: Neural Human Nervous System

Class 11, Chapter 19: Chemical Coordination and Integration

Printed pages 239–252. 10 lines tested by 11 questions.

Topics in this chapter (2), in NCERT order

Endocrine Hypothalamus Pituitary Thyroidp. 2396 PYQs
Endocrine Adrenal Pancreas Gonadsp. 2446 PYQs

The Hypothalamus
In short: The hypothalamus is the basal part of the diencephalon (forebrain) and regulates a wide spectrum of body functions
NCERT Class 11 Biology, Ch. 19, p. 240, section 19.2.1
Tested in: NEET 2024 Q170
Learn it: Neural Human Nervous System · Endocrine Hypothalamus Pituitary Thyroid
The Pituitary Gland
Tested 2 times
In short: The pituitary is in the sella tursica, attached to the hypothalamus by a stalk, and divided into adenohypophysis and neurohypophysis
NCERT Class 11 Biology, Ch. 19, p. 241, section 19.2.2
Tested in: NEET 2025 Q120, NEET 2024 Q200
Learn it: Endocrine Hypothalamus Pituitary Thyroid
Thyroid Gland
In short: The thyroid gland has two lobes on either side of the trachea, interconnected by a thin flap of connective tissue called the isthmus, and is composed of follicles and stromal tissue
NCERT Class 11 Biology, Ch. 19, p. 242, section 19.2.4
Tested in: NEET 2024 Q200
Learn it: Endocrine Hypothalamus Pituitary Thyroid
Hyperthyroidism and Exophthalmic Goitre
Tested 3 times
In short: Due to cancer of the thyroid gland or nodule development, the rate of synthesis and secretion of thyroid hormones can increase to abnormally high levels, a condition called hyperthyroidism, which adversely affects body physiology
NCERT Class 11 Biology, Ch. 19, p. 243, section 19.2.4
Tested in: NEET 2024 Q200, NEET 2023 Q190, NEET 2020 Q98
Learn it: Endocrine Hypothalamus Pituitary Thyroid · Endocrine Adrenal Pancreas Gonads
Parathyroid Gland and Thymus
In short: In humans, four parathyroid glands are present on the back of the thyroid gland, one pair in each lobe
NCERT Class 11 Biology, Ch. 19, p. 243, section 19.2.5-19.2.6
Tested in: NEET 2022 Q192
Learn it: Endocrine Hypothalamus Pituitary Thyroid
Adrenal Medulla and Addison's Disease
Tested 2 times
In short: The body has one pair of adrenal glands, one above each kidney
NCERT Class 11 Biology, Ch. 19, p. 244, section 19.2.7
Tested in: NEET 2025 Q105, NEET 2020 Q98
Learn it: Endocrine Adrenal Pancreas Gonads
Adrenal Cortex Hormones
In short: The adrenal cortex has three layers: zona reticularis (inner), zona fasciculata (middle) and zona glomerulosa (outer)
NCERT Class 11 Biology, Ch. 19, p. 245, section 19.2.7
Tested in: NEET 2025 Q135
Learn it: Endocrine Adrenal Pancreas Gonads
Pancreas: Glucagon and Insulin
In short: The pancreas is a composite gland acting as both exocrine and endocrine gland
NCERT Class 11 Biology, Ch. 19, p. 245, section 19.2.8
Tested in: NEET 2024 Q156
Learn it: Endocrine Adrenal Pancreas Gonads
Diabetes Mellitus
In short: As a result of insulin action, glucose moves rapidly from blood into hepatocytes and adipocytes, decreasing blood glucose levels (hypoglycemia)
NCERT Class 11 Biology, Ch. 19, p. 246, section 19.2.8
Tested in: NEET 2020 Q98
Learn it: Endocrine Adrenal Pancreas Gonads
Hormones of Heart, Kidney and Gastrointestinal Tract
Tested 3 times
In short: Hormones are also secreted by tissues that are not endocrine glands
NCERT Class 11 Biology, Ch. 19, p. 247, section 19.3
Tested in: NEET 2025 Q135, NEET 2023 Q167, NEET 2023 Q193
Learn it: Endocrine Adrenal Pancreas Gonads · Excretion Regulation Disorders

Class 11 (pre-2023 edition), Chapter 12: Mineral Nutrition

Printed pages 194–205. 2 lines tested by 1 question. This chapter is not in the current (2023 rationalised) NCERT book; pages are from the pre-2023 edition.

Iron and manganese functions in photosynthesis
“It activates catalase enzyme, and is essential for the formation of chlorophyll”
NCERT Class 11 Biology (pre-2023 edition), Ch. 12, p. 198, section 12.2.2
Tested in: NEET 2020 Q102
Zinc and boron functions in plant growth
“It is also needed in the synthesis of auxin”
NCERT Class 11 Biology (pre-2023 edition), Ch. 12, p. 198, section 12.2.2
Tested in: NEET 2020 Q102

Class 11 (pre-2023 edition), Chapter 16: Digestion and Absorption

Printed pages 255–267. 5 lines tested by 5 questions. This chapter is not in the current (2023 rationalised) NCERT book; pages are from the pre-2023 edition.

Small intestine regions: duodenum, jejunum, ileum
“Small intestine is distinguishable into three regions, a 'C' shaped duodenum, a long coiled middle portion jejunum and a highly coiled ileum”
NCERT Class 11 Biology (pre-2023 edition), Ch. 16, p. 259, section 16.1.1
Tested in: NEET 2020 Q96
Sphincter of Oddi at hepato-pancreatic duct
“The bile duct and the pancreatic duct open together into the duodenum as the common hepato-pancreatic duct which is guarded by a sphincter called the sphincter of Oddi”
NCERT Class 11 Biology (pre-2023 edition), Ch. 16, p. 261, section 16.1.1
Tested in: NEET 2021 Q175
Succus entericus is the intestinal juice
“…the secretions of the brush border cells of the mucosa alongwith the secretions of the goblet cells constitute the intestinal juice or succus entericus”
NCERT Class 11 Biology (pre-2023 edition), Ch. 16, p. 262, section 16.2
Tested in: NEET 2021 Q153
Digestive enzymes
In short: Saliva: amylase (starch → maltose)
NCERT Class 11 Biology (pre-2023 edition), Ch. 16, p. 263, section 16.3
Tested in: NEET 2022 Q172
Ileo-caecal valve prevents backflow
“The undigested, unabsorbed substances called faeces enters into the caecum of the large intestine through ileo-caecal valve, which prevents the back flow of the faecal matter”
NCERT Class 11 Biology (pre-2023 edition), Ch. 16, p. 264, section 16.2/16.3
Tested in: NEET 2023 Q161

Class 12, Chapter 1: Sexual Reproduction in Flowering Plants

Printed pages 1–25. 12 lines tested by 11 questions.

Topics in this chapter (4), in NCERT order

Flower Structure Gametogenesisp. 66 PYQs
Pollination Fertilizationp. 1210 PYQs
Post Fertilization Seed Fruitp. 184 PYQs
Apomixis Polyembryonyp. 230 PYQs

Pollen grain is the male gametophyte
“Pollen grain: The pollen grains represent the male gametophytes. If you touch the opened anthers of Hibiscus or any other flower you would find deposition of yellowish powdery pollen grains on your fingers”
NCERT Class 12 Biology, Ch. 1, p. 6, section 1.2.1
Tested in: NEET 2020 Q92
Learn it: Flower Structure Gametogenesis
Pollen viability duration varies by species
“In some cereals such as rice and wheat, pollen grains lose viability within 30 minutes of their release”
NCERT Class 12 Biology, Ch. 1, p. 8, section 1.2.1
Tested in: NEET 2021 Q145
Learn it: Pollination Fertilization
Embryo sac is the female gametophyte in nucellus
“Located in the nucellus is the embryo sac or female gametophyte”
NCERT Class 12 Biology, Ch. 1, p. 9, section 1.2.2
Tested in: NEET 2020 Q92
Learn it: Flower Structure Gametogenesis
MMC: one meiosis then three mitoses form embryo sac
“The MMC undergoes meiotic division. What is the importance of the MMC undergoing meiosis? Meiosis results in the production of four megaspores”
NCERT Class 12 Biology, Ch. 1, p. 10, section 1.2.2
Tested in: NEET 2025 Q97
Learn it: Flower Structure Gametogenesis · Pollination Fertilization
Egg apparatus vs polar nuclei in embryo sac
“Three cells are grouped together at the micropylar end and constitute the egg apparatus. The egg apparatus, in turn, consists of two synergids and one egg cell”
NCERT Class 12 Biology, Ch. 1, p. 11, section 1.2.2
Tested in: NEET 2025 Q139
Learn it: Flower Structure Gametogenesis
Xenogamy: pollen to a different plant's stigma
“Xenogamy – Transfer of pollen grains from anther to the stigma of a different plant”
NCERT Class 12 Biology, Ch. 1, p. 12, section 1.2.3
Tested in: NEET 2021 Q113
Learn it: Pollination Fertilization
Wind/water pollination produces enormous pollen
“To compensate for this uncertainties and associated loss of pollen grains, the flowers produce enormous amount of pollen when compared to the number of ovules available for pollination”
NCERT Class 12 Biology, Ch. 1, p. 12, section 1.2.3
Tested in: NEET 2025 Q142
Learn it: Pollination Fertilization
Pollination & double fertilization
In short: Pollination: self (autogamy, geitonogamy) vs cross (xenogamy)
NCERT Class 12 Biology, Ch. 1, p. 12, section 1.5
Tested in: NEET 2023 Q131
Learn it: Pollination Fertilization
Corn cob stigma-style waves in wind to trap pollen
“…a familiar example is the corn cob – the ears you see are nothing but the stigma and style which wave in the wind to trap pollen grains”
NCERT Class 12 Biology, Ch. 1, p. 13, section 1.2.3
Tested in: NEET 2023 Q130
Learn it: Pollination Fertilization
Water pollination: waterlily, mucilage, ribbon pollen
“In a majority of aquatic plants such as water hyacinth and water lily, the flowers emerge above the level of water and are pollinated by insects or wind”
NCERT Class 12 Biology, Ch. 1, p. 13, section 1.2.3
Tested in: NEET 2024 Q111
Learn it: Pollination Fertilization
Wind and water pollinated flowers lack colour and nectar
Tested 3 times
“Both wind and water pollinated flowers are not very colourful and do not produce nectar”
NCERT Class 12 Biology, Ch. 1, p. 13, section 1.2.3
Tested in: NEET 2025 Q142, NEET 2024 Q111, NEET 2022 Q117
Learn it: Pollination Fertilization
Insect-pollinated flowers are large, colourful, nectar-rich
Tested 2 times
“Majority of insect-pollinated flowers are large, colourful, fragrant and rich in nectar”
NCERT Class 12 Biology, Ch. 1, p. 14, section 1.2.3
Tested in: NEET 2023 Q122, NEET 2022 Q117
Learn it: Pollination Fertilization

Class 12, Chapter 2: Human Reproduction

Printed pages 26–40. 14 lines tested by 13 questions.

Topics in this chapter (4), in NCERT order

Vas deferens: seminal vesicle duct, ejaculatory duct
“It receives a duct from seminal vesicle and opens into urethra as the ejaculatory duct”
NCERT Class 12 Biology, Ch. 2, p. 27, section 2.1
Tested in: NEET 2023 Q171
Learn it: Male Reproductive System
Female reproductive system
In short: Ovaries — oogonia → primary oocyte (arrested in prophase I) → secondary oocyte at puberty (haploid, arrested in metaphase II)
NCERT Class 12 Biology, Ch. 2, p. 28, section 2.2
Tested in: NEET 2022 Q160
Learn it: Female Reproductive System
Fallopian tube regions: infundibulum, ampulla, isthmus
“…the part closer to the ovary is the funnel-shaped infundibulum”
NCERT Class 12 Biology, Ch. 2, p. 29, section 2.2
Tested in: NEET 2024 Q154
Learn it: Female Reproductive System
Hymen not a reliable indicator of virginity
“The hymen is often torn during the first coitus (intercourse). However, it can also be broken by a sudden fall or jolt, insertion of a vaginal tampon, active participation in some sports like horseback riding, cycling”
NCERT Class 12 Biology, Ch. 2, p. 30, section 2.2
Tested in: NEET 2024 Q185
Learn it: Female Reproductive System
Cervical canal with vagina forms birth canal
“The uterus opens into vagina through a narrow cervix. The cavity of the cervix is called cervical canal”
NCERT Class 12 Biology, Ch. 2, p. 30, section 2.2
Tested in: NEET 2023 Q171
Learn it: Male Reproductive System
Spermiogenesis and spermiation defined
“The spermatids are transformed into spermatozoa (sperms) by the process called spermiogenesis”
NCERT Class 12 Biology, Ch. 2, p. 31, section 2.3
Tested in: NEET 2022 Q171
Learn it: Male Reproductive System
LH-Leydig-androgens; FSH-Sertoli-spermiogenesis
“LH acts at the Leydig cells and stimulates synthesis and secretion of androgens. Androgens, in turn, stimulate the process of spermatogenesis”
NCERT Class 12 Biology, Ch. 2, p. 31, section 2.3
Tested in: NEET 2024 Q164
Learn it: Male Reproductive System
Oogenesis begins in embryo; spermatogenesis at puberty
“…produce sperms by spermatogenesis that begins at puberty”
NCERT Class 12 Biology, Ch. 2, p. 32, section 2.3
Tested in: NEET 2022 Q163
Learn it: Male Reproductive System · Female Reproductive System
Sperm structure: nucleus, acrosome, mitochondria, tail
“The sperm head contains an elongated haploid nucleus, the anterior portion of which is covered by a cap-like structure, acrosome”
NCERT Class 12 Biology, Ch. 2, p. 32, section 2.3
Tested in: NEET 2025 Q150
Learn it: Male Reproductive System
Menarche; missed menstruation may indicate pregnancy
“The first menstruation begins at puberty and is called menarche”
NCERT Class 12 Biology, Ch. 2, p. 33, section 2.4
Tested in: NEET 2025 Q92
Learn it: Menstrual Cycle
LH and FSH stimulate follicles to secrete estrogen
“…gonadotropins (LH and FSH) increases gradually during the follicular phase, and stimulates follicular development as well as secretion of estrogens by the growing follicles”
NCERT Class 12 Biology, Ch. 2, p. 35, section 2.4
Tested in: NEET 2024 Q164
Learn it: Male Reproductive System
Endometrium needed for implantation; corpus luteum degeneration
“Such an endometrium is necessary for implantation of the fertilised ovum and other events of pregnancy”
NCERT Class 12 Biology, Ch. 2, p. 35, section 2.4
Tested in: NEET 2023 Q181
Learn it: Fertilization Pregnancy
Fertilisation: zona pellucida contact completes oocyte meiosis
Tested 2 times
“During fertilisation, a sperm comes in contact with the zona pellucida layer of the ovum”
NCERT Class 12 Biology, Ch. 2, p. 35, section 2.5
Tested in: NEET 2021 Q163, NEET 2020 Q111
Learn it: Female Reproductive System · Fertilization Pregnancy
Embryonic development timeline: heart, limbs, organs, hair
“In human beings, after one month of pregnancy, the embryo's heart is formed”
NCERT Class 12 Biology, Ch. 2, p. 38, section 2.6
Tested in: NEET 2025 Q157
Learn it: Fertilization Pregnancy

Class 12, Chapter 3: Reproductive Health

Printed pages 41–50. 14 lines tested by 10 questions.

Topics in this chapter (3), in NCERT order

Contraception methods
In short: Natural (rhythm, withdrawal, lactational amenorrhoea), barrier (condoms, diaphragm, IUDs — Cu releasing, hormonal — Mirena), oral (Mala-D, Saheli — non-steroidal), implants/injections, surgical (vasectomy, tubectomy)
NCERT Class 12 Biology, Ch. 3, p. 44, section 3.3
Tested in: NEET 2024 Q172
Learn it: Birth Control Methods
IUD types: non-medicated, copper, hormone releasing
Tested 3 times
“These Intra Uterine Devices are presently available as the non-medicated IUDs (e.g., Lippes loop), copper releasing IUDs (CuT, Cu7, Multiload 375) and the hormone releasing IUDs (Progestasert, LNG-20)”
NCERT Class 12 Biology, Ch. 3, p. 44, section 3.3
Tested in: NEET 2024 Q179, NEET 2022 Q159, NEET 2021 Q181
Learn it: Birth Control Methods
Barrier methods block cervix (diaphragm, caps, vaults)
Tested 3 times
“In barrier methods, ovum and sperms are prevented from physically meeting with the help of barriers”
NCERT Class 12 Biology, Ch. 3, p. 44, section 3.3
Tested in: NEET 2023 Q162, NEET 2022 Q198, NEET 2021 Q174
Learn it: Birth Control Methods
IUDs increase phagocytosis of sperms in uterus
Tested 2 times
“IUDs increase phagocytosis of sperms within the uterus and the Cu ions released suppress sperm motility and the fertilising capacity of sperms”
NCERT Class 12 Biology, Ch. 3, p. 44, section 3.3
Tested in: NEET 2022 Q198, NEET 2021 Q174
Learn it: Birth Control Methods
Lactational amenorrhea prevents ovulation after parturition
“Lactational amenorrhea (absence of menstruation) method is based on the fact that ovulation”
NCERT Class 12 Biology, Ch. 3, p. 44, section 3.3
Tested in: NEET 2022 Q198
Learn it: Birth Control Methods
Withdrawal/coitus interruptus is a natural method
“Natural methods work on the principle of avoiding chances of ovum and sperms meeting”
NCERT Class 12 Biology, Ch. 3, p. 44, section 3.3
Tested in: NEET 2023 Q162
Learn it: Birth Control Methods
Implants deliver progestogens under the skin
“Progestogens alone or in combination with estrogen can also be used by females as injections or implants under the skin”
NCERT Class 12 Biology, Ch. 3, p. 45, section 3.3
Tested in: NEET 2024 Q179
Learn it: Birth Control Methods
Contraceptive pills inhibit ovulation and implantation
“They inhibit ovulation and implantation as well as”
NCERT Class 12 Biology, Ch. 3, p. 45, section 3.3
Tested in: NEET 2022 Q198
Learn it: Birth Control Methods
Surgical sterilisation: vasectomy (male), tubectomy (female)
“Surgical methods, also called sterilisation, are generally advised for the male/female partner as a terminal method to prevent any more”
NCERT Class 12 Biology, Ch. 3, p. 45, section 3.3
Tested in: NEET 2023 Q162
Learn it: Birth Control Methods
Saheli is an oral non-steroidal contraceptive
“Saheli–the new oral contraceptive for the females contains a non-steroidal preparation. It is a ‘once a week’ pill with very few side effects and high contraceptive value”
NCERT Class 12 Biology, Ch. 3, p. 45, section 3.3
Tested in: NEET 2023 Q162
Learn it: Birth Control Methods
Vasectomy removes vas deferens; tubectomy removes fallopian tube
“In vasectomy, a small part of the vas deferens is removed or tied up through a small incision on the scrotum”
NCERT Class 12 Biology, Ch. 3, p. 46, section 3.3
Tested in: NEET 2021 Q174
Learn it: Birth Control Methods
STDs & infertility
In short: STDs: gonorrhoea, syphilis, chlamydia, trichomoniasis, genital herpes, HPV (genital warts), HIV/AIDS
NCERT Class 12 Biology, Ch. 3, p. 47, section 3.4
Tested in: NEET 2020 Q99
Learn it: Reproductive Health STDs
Gonorrhoea is a curable STI
“Gonorrhoea, syphilis, genital herpes, chlamydiasis, genital warts, trichomoniasis, hepatitis-B and of course, the most discussed infection in the recent years, HIV leading to AIDS are some of the common STIs”
NCERT Class 12 Biology, Ch. 3, p. 47, section 3.4
Tested in: NEET 2023 Q164
Learn it: Reproductive Health STDs
Amniocentesis & ART
In short: Amniocentesis: foetal-cell analysis from amniotic fluid for chromosomal abnormalities
NCERT Class 12 Biology, Ch. 3, p. 48, section 3.5
Tested in: NEET 2023 Q174
Learn it: Amniocentesis Art

Class 12, Chapter 4: Principles of Inheritance and Variation

Printed pages 51–78. 12 lines tested by 17 questions.

Topics in this chapter (6), in NCERT order

Mendel Inheritancep. 598 PYQs
Incomplete Dominance Codominancep. 606 PYQs
Linkage Recombination Mappingp. 673 PYQs
Sex Determination Linkagep. 712 PYQs
Mendelian Disorders Pedigreep. 724 PYQs
Mutations Genetic Disordersp. 735 PYQs

Mendel's 14 varieties, 7 characters
Tested 2 times
“Mendel selected 14 true-breeding pea plant varieties, as pairs which were similar except for one character with contrasting traits”
NCERT Class 12 Biology, Ch. 4, p. 54, section 4.1
Tested in: NEET 2022 Q135, NEET 2020 Q130
Learn it: Mendel Inheritance
Punnett square diagram
“The production of gametes by the parents, the formation of the zygotes, the F1 and F2 plants can be understood from a diagram called Punnett Square”
NCERT Class 12 Biology, Ch. 4, p. 57, section 4.2
Tested in: NEET 2021 Q109
Learn it: Mendel Inheritance
Mendel's laws
Tested 3 times
In short: Law of dominance, segregation (purity of gametes), independent assortment
NCERT Class 12 Biology, Ch. 4, p. 59, section 4.1
Tested in: NEET 2025 Q94, NEET 2024 Q133, NEET 2021 Q184
Learn it: Mendel Inheritance · Mendelian Disorders Pedigree
Law of Dominance statements
“Characters are controlled by discrete units called factors. (ii) Factors occur in pairs. (iii) In a dissimilar pair of factors one member of the pair dominates (dominant) the other (recessive)”
NCERT Class 12 Biology, Ch. 4, p. 59, section 4.2.1
Tested in: NEET 2024 Q123
Learn it: Mendel Inheritance
Inheritance patterns
Tested 3 times
In short: Incomplete dominance: snapdragon RR (red), Rr (pink), rr (white)
NCERT Class 12 Biology, Ch. 4, p. 60, section 4.2
Tested in: NEET 2024 Q131, NEET 2023 Q101, NEET 2020 Q121
Learn it: Incomplete Dominance Codominance
Sturtevant maps genes via recombination frequency
“His student Alfred Sturtevant used the frequency of recombination between gene pairs on the same chromosome as a measure of the distance between genes and 'mapped' their position on the chromosome”
NCERT Class 12 Biology, Ch. 4, p. 67, section 4.3.3
Tested in: NEET 2023 Q126
Learn it: Linkage Recombination Mapping
Linkage & crossing over
Tested 2 times
In short: Linkage: genes on same chromosome inherited together
NCERT Class 12 Biology, Ch. 4, p. 67, section 4.4
Tested in: NEET 2022 Q150, NEET 2022 Q188
Learn it: Linkage Recombination Mapping
XO sex determination in grasshopper
“…in a large number of insects the mechanism of sex determination is of the XO type, i.e., all eggs bear an additional X-chromosome besides the other chromosomes”
NCERT Class 12 Biology, Ch. 4, p. 70, section 4.6
Tested in: NEET 2022 Q126
Learn it: Sex Determination Linkage
Genetic disorders
In short: Mendelian: sickle cell anaemia (autosomal recessive), thalassaemia, phenylketonuria, haemophilia (X-linked recessive)
NCERT Class 12 Biology, Ch. 4, p. 73, section 4.7
Tested in: NEET 2021 Q184
Learn it: Mendelian Disorders Pedigree · Mutations Genetic Disorders
Pedigree examples: dominant vs recessive trait
“A representative pedigree is shown in Figure 4.14 for dominant and recessive traits”
NCERT Class 12 Biology, Ch. 4, p. 73, section 4.8.2
Tested in: NEET 2022 Q142
Learn it: Mendelian Disorders Pedigree
Chromosome locations: Klinefelter, Thalassemia genes
“…caused due to the presence of an additional copy of X-chromosome resulting into a karyotype of 47, XXY”
NCERT Class 12 Biology, Ch. 4, p. 75, section 4.8.2/4.8.3
Tested in: NEET 2024 Q163
Learn it: Mutations Genetic Disorders
Down's syndrome: trisomy 21, palm crease
Tested 2 times
“…the presence of an additional copy of the chromosome number 21 (trisomy of 21)”
NCERT Class 12 Biology, Ch. 4, p. 76, section 4.8.3
Tested in: NEET 2024 Q163, NEET 2023 Q155
Learn it: Mutations Genetic Disorders

Class 12, Chapter 5: Molecular Basis of Inheritance

Printed pages 79–109. 25 lines tested by 31 questions.

Topics in this chapter (7), in NCERT order

DNA RNA Structurep. 811 PYQ
Genetic Material DNA Packagingp. 839 PYQs
DNA Replicationp. 894 PYQs
Genetic Codep. 951 PYQ
Transcription Translationp. 9515 PYQs
Gene Regulation Lac Operonp. 1004 PYQs
Human Genome Projectp. 1024 PYQs

DNA structure
Tested 2 times
In short: Watson-Crick double helix: antiparallel strands
NCERT Class 12 Biology, Ch. 5, p. 81, section 5.1
Tested in: NEET 2023 Q198, NEET 2021 Q176
Learn it: DNA RNA Structure · Transcription Translation
Packaging of DNA Helix
Tested 3 times
In short: The distance between two consecutive base pairs in DNA is 0.34 nm
NCERT Class 12 Biology, Ch. 5, p. 83, section 5.1.2
Tested in: NEET 2023 Q151, NEET 2022 Q185, NEET 2020 Q106
Learn it: Genetic Material DNA Packaging
Packaging of DNA Helix
Tested 3 times
In short: In eukaryotes, positively charged basic proteins called histones, rich in the basic amino acid residues lysine and arginine, organise into a unit of eight molecules called a histone octamer
NCERT Class 12 Biology, Ch. 5, p. 83, section 5.1.2
Tested in: NEET 2025 Q111, NEET 2023 Q151, NEET 2022 Q115
Learn it: Genetic Material DNA Packaging
Packaging of DNA Helix
Tested 2 times
In short: The beads-on-string chromatin is packaged into chromatin fibers, further coiled and condensed at the metaphase stage of cell division to form chromosomes
NCERT Class 12 Biology, Ch. 5, p. 84, section 5.1.2
Tested in: NEET 2025 Q168, NEET 2022 Q115
Learn it: Genetic Material DNA Packaging
Transforming Principle (Griffith)
Tested 2 times
In short: In 1928, Frederick Griffith worked with Streptococcus pneumoniae, which forms smooth (S, mucous/polysaccharide coat, virulent) or rough (R, no coat, non-virulent) colonies
NCERT Class 12 Biology, Ch. 5, p. 84, section 5.2
Tested in: NEET 2025 Q168, NEET 2024 Q148
Learn it: Genetic Material DNA Packaging
The Genetic Material is DNA (Hershey-Chase)
Tested 2 times
In short: Alfred Hershey and Martha Chase (1952) worked with bacteriophages
NCERT Class 12 Biology, Ch. 5, p. 85, section 5.2.1
Tested in: NEET 2025 Q168, NEET 2023 Q134
Learn it: Genetic Material DNA Packaging
RNA mutates faster than DNA
“Both DNA and RNA are able to mutate. In fact, RNA being unstable, mutate at a faster rate”
NCERT Class 12 Biology, Ch. 5, p. 87, section 5.2.2
Tested in: NEET 2023 Q156
Learn it: Viruses Viroids Lichens
RNA World
In short: RNA was the first genetic material
NCERT Class 12 Biology, Ch. 5, p. 88, section 5.3
Tested in: NEET 2025 Q159
Learn it: Genetic Material DNA Packaging
DNA replication
In short: Semi-conservative (Meselson-Stahl 1958, ¹⁵N → ¹⁴N density gradient)
NCERT Class 12 Biology, Ch. 5, p. 89, section 5.4
Tested in: NEET 2024 Q148
Learn it: Genetic Material DNA Packaging · DNA Replication
DNA polymerase synthesises only 5' to 3'
“…catalyse polymerisation only in one direction, that is 5'à3'”
NCERT Class 12 Biology, Ch. 5, p. 90, section 5.4.2
Tested in: NEET 2024 Q139
Learn it: DNA Replication
DNA ligase joins discontinuous fragments
“The discontinuously synthesised fragments are later joined by the enzyme DNA ligase”
NCERT Class 12 Biology, Ch. 5, p. 90, section 5.4.2
Tested in: NEET 2020 Q133
Learn it: rDNA Tools Restriction Ligase
Eukaryotic DNA replication occurs in S phase
“In eukaryotes, the replication of DNA takes place at S-phase of the cell-cycle”
NCERT Class 12 Biology, Ch. 5, p. 91, section 5.4.2
Tested in: NEET 2023 Q118
Learn it: DNA Replication
Transcription unit: promoter, gene, terminator
“A transcription unit in DNA is defined primarily by the three regions in the DNA: (i) A Promoter (ii) The Structural gene (iii) A Terminator”
NCERT Class 12 Biology, Ch. 5, p. 91, section 5.5.1
Tested in: NEET 2024 Q132
Learn it: Transcription Translation
RNA polymerase opens DNA helix
“It somehow also facilitates opening of the helix and continues elongation”
NCERT Class 12 Biology, Ch. 5, p. 94, section 5.5.3
Tested in: NEET 2020 Q116
Learn it: Transcription Translation
Sigma initiates, rho terminates transcription
Tested 2 times
“The RNA polymerase is only capable of catalysing the process of elongation. It associates transiently with initiation-factor (σ) and termination-factor (ρ) to initiate and terminate the transcription, respectively”
NCERT Class 12 Biology, Ch. 5, p. 94, section 5.5.3
Tested in: NEET 2025 Q119, NEET 2021 Q146
Learn it: Transcription Translation
Transcription & translation
Tested 2 times
In short: Transcription: DNA → mRNA via RNA polymerase
NCERT Class 12 Biology, Ch. 5, p. 95, section 5.5
Tested in: NEET 2023 Q107, NEET 2021 Q136
Learn it: Transcription Translation
Processed hnRNA becomes mRNA, then exported
“…hnRNA undergoes additional processing called as capping and tailing”
NCERT Class 12 Biology, Ch. 5, p. 95, section 5.5.3
Tested in: NEET 2025 Q166
Learn it: Transcription Translation
Genetic Code
Tested 2 times
In short: George Gamow, a physicist, argued that since there are only 4 bases and they must code for 20 amino acids, the code should be a combination of bases, and proposed that the code is made of three nucleotides (a triplet), since a permutation of 4^3 (4x4x4) generates 64 codons, more than the 20 required
NCERT Class 12 Biology, Ch. 5, p. 95, section 5.6
Tested in: NEET 2025 Q107, NEET 2024 Q148
Learn it: Genetic Code · Genetic Material DNA Packaging
Aminoacylation is first phase of translation
“…in the first phase itself amino acids are activated in the presence of ATP and linked to their cognate tRNA– a process commonly called as charging of tRNA or aminoacylation of tRNA to be more specific”
NCERT Class 12 Biology, Ch. 5, p. 98, section 5.7
Tested in: NEET 2020 Q123
Learn it: Transcription Translation
Translation begins at small subunit-mRNA encounter
“When the small subunit encounters an mRNA, the process of translation of the mRNA to protein begins”
NCERT Class 12 Biology, Ch. 5, p. 99, section 5.7
Tested in: NEET 2022 Q132
Learn it: Transcription Translation
Lac operon
In short: Jacob-Monod model
NCERT Class 12 Biology, Ch. 5, p. 100, section 5.7
Tested in: NEET 2023 Q168
Learn it: Gene Regulation Lac Operon
Permease transports lactose into cell
“…the lactose is transported into the cells through the action of permease”
NCERT Class 12 Biology, Ch. 5, p. 101, section 5.8
Tested in: NEET 2024 Q112
Learn it: Gene Regulation Lac Operon
HGP: ESTs vs sequence annotation approaches
Tested 2 times
“One approach focused on identifying all the genes that are expressed as RNA (referred to as Expressed Sequence Tags (ESTs)”
NCERT Class 12 Biology, Ch. 5, p. 103, section 5.9
Tested in: NEET 2023 Q125, NEET 2022 Q144
Learn it: Human Genome Project
Chromosome 1 has the most genes
“Chromosome 1 has most genes (2968), and the Y has the fewest (231)”
NCERT Class 12 Biology, Ch. 5, p. 104, section 5.9.1
Tested in: NEET 2025 Q169
Learn it: Human Genome Project
DNA fingerprinting targets repetitive DNA
“DNA fingerprinting involves identifying differences in some specific regions in DNA sequence called as repetitive DNA, because in these sequences, a small stretch of DNA is repeated many times”
NCERT Class 12 Biology, Ch. 5, p. 105, section 5.10
Tested in: NEET 2021 Q139
Learn it: Human Genome Project

Class 12, Chapter 6: Evolution

Printed pages 110–126. 8 lines tested by 9 questions.

Topics in this chapter (5), in NCERT order

Homology/divergent vs analogy/convergent evolution
Tested 2 times
“This is divergent evolution and these structures are homologous”
NCERT Class 12 Biology, Ch. 6, p. 114, section 6.2
Tested in: NEET 2025 Q109, NEET 2021 Q187
Learn it: Evidences Evolution
Evolution by anthropogenic action
Tested 2 times
“Man has bred selected plants and animals for agriculture, horticulture, sport or security”
NCERT Class 12 Biology, Ch. 6, p. 115, section 6.3
Tested in: NEET 2021 Q187, NEET 2020 Q97
Learn it: Evidences Evolution · Natural Selection Drift
Penguin and dolphin flippers are analogous, convergent
Tested 2 times
“…analogous structures are a result of convergent evolution - different structures evolving for the same function and hence having similarity”
NCERT Class 12 Biology, Ch. 6, p. 115, section 6.3
Tested in: NEET 2024 Q153, NEET 2022 Q197
Learn it: Evidences Evolution
Adaptive radiation: Darwin's finches, Australian marsupials
“This process of evolution of different species in a given geographical area starting from a point and literally radiating to other areas of geography (habitats) is called adaptive radiation. Darwin’s finches represent one of the best examples of this phenomenon”
NCERT Class 12 Biology, Ch. 6, p. 117, section 6.4
Tested in: NEET 2021 Q187
Learn it: Evidences Evolution
Hardy-Weinberg: constant gene pool vs the five disturbing factors
“This principle says that allele frequencies in a population are stable and is constant from generation to generation. The gene pool (total genes and their alleles in a population) remains a constant. This is called genetic equilibrium”
NCERT Class 12 Biology, Ch. 6, p. 120, section 6.7
Tested in: NEET 2024 Q159
Learn it: Hardy Weinberg Principle
Stabilising, directional, disruptive natural selection
“Natural selection can lead to stabilisation (in which more individuals acquire mean character value), directional change (more individuals acquire value other than the mean character value) or disruption (more individuals acquire peripheral character value at both ends of the distribution curve)”
NCERT Class 12 Biology, Ch. 6, p. 121, section 6.6
Tested in: NEET 2022 Q183
Learn it: Natural Selection Drift
Genetic drift by chance produces founder effect
“If the same change occurs by chance, it is called genetic drift”
NCERT Class 12 Biology, Ch. 6, p. 121, section 6.7
Tested in: NEET 2021 Q118
Learn it: Natural Selection Drift
Hominid evolution
In short: Dryopithecus → Ramapithecus → Australopithecus (3-4 mya) → Homo habilis (1.5-2 mya, tool maker) → Homo erectus (Java, 1.5 mya) → Homo neanderthalensis (1L brain) → Homo sapiens (~75 kya, Africa origin)
NCERT Class 12 Biology, Ch. 6, p. 124, section 6.10
Tested in: NEET 2024 Q155
Learn it: Hominid Evolution

Class 12, Chapter 7: Human Health and Disease

Printed pages 127–148. 20 lines tested by 16 questions.

Topics in this chapter (4), in NCERT order

Health Disease Pathogensp. 1306 PYQs
Immunity Innate Acquiredp. 13410 PYQs
AIDS Cancerp. 1413 PYQs
Drugs Addictionp. 1423 PYQs

Common diseases
Tested 2 times
In short: Bacterial: typhoid (Salmonella typhi — Widal test), pneumonia (Streptococcus pneumoniae)
NCERT Class 12 Biology, Ch. 7, p. 130, section 7.1
Tested in: NEET 2024 Q177, NEET 2020 Q109
Learn it: Health Disease Pathogens
Pneumonia bacteria and malaria Plasmodium species
“Bacteria like Streptococcus pneumoniae and Haemophilus influenzae are responsible for the disease pneumonia in humans”
NCERT Class 12 Biology, Ch. 7, p. 131, section 7.1
Tested in: NEET 2023 Q173
Learn it: Health Disease Pathogens
Haemozoin released on RBC rupture in malaria
“The rupture of RBCs is associated with release of a toxic substance, haemozoin, which is responsible for the chill and high fever recurring every three to four days”
NCERT Class 12 Biology, Ch. 7, p. 131, section 7.1
Tested in: NEET 2024 Q177
Learn it: Health Disease Pathogens
Rhinoviruses cause the common cold
“Rhino viruses represent one such group of viruses which cause one of the most infectious human ailments – the common cold”
NCERT Class 12 Biology, Ch. 7, p. 131, section 7.1
Tested in: NEET 2024 Q177
Learn it: Health Disease Pathogens
Ringworm fungi and filarial worm species
“…fungi belonging to the genera Microsporum, Trichophyton and Epidermophyton are responsible for ringworms”
NCERT Class 12 Biology, Ch. 7, p. 133, section 7.1
Tested in: NEET 2023 Q173
Learn it: Health Disease Pathogens
Immunity
Tested 4 times
In short: Innate (non-specific): physical (skin), physiological (acid pH), cellular (NK cells, macrophages), cytokine
NCERT Class 12 Biology, Ch. 7, p. 134, section 7.2
Tested in: NEET 2025 Q118, NEET 2024 Q175, NEET 2022 Q186, NEET 2020 Q131
Learn it: Immunity Innate Acquired
Allergy definition; dust mites as allergen
“The exaggerated response of the immune system to certain antigens present in the environment is called allergy”
NCERT Class 12 Biology, Ch. 7, p. 137, section 7.2.5
Tested in: NEET 2024 Q177
Learn it: Health Disease Pathogens
Auto-immune disease definition; rheumatoid arthritis example
“…the body attacks self-cells. This results in damage to the body and is called auto-immune disease”
NCERT Class 12 Biology, Ch. 7, p. 137, section 7.2.6
Tested in: NEET 2022 Q179
Learn it: Immunity Innate Acquired
Primary and secondary lymphoid organs
“The primary lymphoid organs are bone marrow and thymus where immature lymphocytes differentiate”
NCERT Class 12 Biology, Ch. 7, p. 137, section 7.2.7
Tested in: NEET 2025 Q124
Learn it: Immunity Innate Acquired
Bone marrow and thymus roles in lymphocyte development
“The bone marrow is the main lymphoid organ where all blood cells including lymphocytes are produced”
NCERT Class 12 Biology, Ch. 7, p. 138, section 7.2.7
Tested in: NEET 2024 Q191
Learn it: Immunity Innate Acquired
ELISA test used for AIDS diagnosis
“A widely used diagnostic test for AIDS is enzyme linked immuno-sorbent assay (ELISA)”
NCERT Class 12 Biology, Ch. 7, p. 140, section 7.3
Tested in: NEET 2021 Q168
Learn it: Health Disease Pathogens
HIV replicates in helper T-lymphocytes
“Simultaneously, HIV enters into helper T-lymphocytes (TH ), replicates and produce progeny viruses”
NCERT Class 12 Biology, Ch. 7, p. 140, section 7.3
Tested in: NEET 2023 Q152
Learn it: AIDS Cancer
CT and MRI detect internal organ cancers
“Techniques like radiography (use of X-rays), CT (computed tomography) and MRI (magnetic resonance imaging) are very useful to detect cancers of the internal organs”
NCERT Class 12 Biology, Ch. 7, p. 141, section 7.4
Tested in: NEET 2025 Q155
Learn it: AIDS Cancer
Leukemia diagnosis: increased blood/bone marrow cell counts
“…blood and bone marrow tests for increased cell counts in the case of leukemias”
NCERT Class 12 Biology, Ch. 7, p. 141, section 7.4
Tested in: NEET 2025 Q155
Learn it: AIDS Cancer
Malignant tumor cell characteristics
“The malignant tumors, on the other hand are a mass of proliferating cells called neoplastic or tumor cells”
NCERT Class 12 Biology, Ch. 7, p. 141, section 7.4
Tested in: NEET 2025 Q140
Learn it: AIDS Cancer
Chemotherapy kills cancerous cells; interferon as biological response modifier
“Several chemotherapeutic drugs are used to kill cancerous cells”
NCERT Class 12 Biology, Ch. 7, p. 142, section 7.4
Tested in: NEET 2025 Q155
Learn it: AIDS Cancer
Heroin depressant; cannabinoid cardiovascular effects
“…heroin is a depressant and slows down body functions”
NCERT Class 12 Biology, Ch. 7, p. 143, section 7.5
Tested in: NEET 2023 Q172
Learn it: Drugs Addiction
Cocaine-dopamine interference; morphine as surgical sedative
Tested 2 times
“It interferes with the transport of the neuro-transmitter dopamine”
NCERT Class 12 Biology, Ch. 7, p. 143, section 7.5
Tested in: NEET 2024 Q168, NEET 2023 Q172
Learn it: Drugs Addiction
Cocaine source: Erythroxylum coca
“Coca alkaloid or cocaine is obtained from coca plant Erythroxylum coca, native to South America”
NCERT Class 12 Biology, Ch. 7, p. 143, section 7.5
Tested in: NEET 2024 Q168
Learn it: Drugs Addiction
Cannabis sativa and Papaver somniferum as drug source plants
“Natural cannabinoids are obtained from the inflorescences of the plant Cannabis sativa”
NCERT Class 12 Biology, Ch. 7, p. 143, section 7.5
Tested in: NEET 2024 Q168
Learn it: Drugs Addiction

Class 12, Chapter 8: Microbes in Human Welfare

Printed pages 149–160. 3 lines tested by 5 questions.

Topics in this chapter (3), in NCERT order

Microbes Household Industrialp. 1516 PYQs
Microbes Sewage Biogasp. 1541 PYQ
Biocontrol Biofertilizersp. 1571 PYQ

Bioactive molecules: streptokinase, cyclosporin A, statins
Tested 3 times
“Examples of acid producers are Aspergillus niger (a fungus) of citric acid, Acetobacter aceti (a bacterium) of acetic acid; Clostridium butylicum (a bacterium) of butyric acid and Lactobacillus (a bacterium) of lactic acid”
NCERT Class 12 Biology, Ch. 8, p. 153, section 9.2.3
Tested in: NEET 2025 Q137, NEET 2024 Q113, NEET 2022 Q166
Learn it: Microbes Household Industrial
Sewage & biogas
In short: Sewage treatment: primary (sedimentation), secondary (aerobic — flocs of microbes
NCERT Class 12 Biology, Ch. 8, p. 154, section 9.4
Tested in: NEET 2020 Q120
Learn it: Microbes Sewage Biogas
Cyanobacteria fix nitrogen as biofertiliser
“Cyanobacteria are autotrophic microbes widely distributed in aquatic and terrestrial environments many of which can fix atmospheric nitrogen, e.g. Anabaena, Nostoc, Oscillatoria, etc”
NCERT Class 12 Biology, Ch. 8, p. 158, section 9.6
Tested in: NEET 2025 Q175
Learn it: Biocontrol Biofertilizers

Class 12, Chapter 9: Biotechnology — Principles and Processes

Printed pages 161–176. 14 lines tested by 18 questions.

Topics in this chapter (3), in NCERT order

rDNA Principlesp. 1643 PYQs
rDNA Tools Restriction Ligasep. 16514 PYQs
rDNA Process PCR Blottingp. 1689 PYQs

Hind II recognition sequence is six base pairs
“It was found that Hind II always cut DNA molecules at a particular point by recognising a specific sequence of six base pairs”
NCERT Class 12 Biology, Ch. 9, p. 165, section 9.2.1
Tested in: NEET 2024 Q103
Learn it: rDNA Tools Restriction Ligase
Tools
Tested 3 times
In short: Restriction enzymes (EcoRI — palindromic site GAATTC, sticky ends)
NCERT Class 12 Biology, Ch. 9, p. 165, section 10.2
Tested in: NEET 2023 Q159, NEET 2022 Q107, NEET 2020 Q112
Learn it: rDNA Tools Restriction Ligase · rDNA Process PCR Blotting
Restriction endonuclease recognises palindromic sequence
“Each restriction endonuclease recognises a specific palindromic nucleotide sequences in the DNA”
NCERT Class 12 Biology, Ch. 9, p. 166, section 9.2.1
Tested in: NEET 2022 Q154
Learn it: rDNA Tools Restriction Ligase
Restriction enzymes cut away from palindrome centre
“Restriction enzymes cut the strand of DNA a little away from the centre of the palindrome sites, but between the same two bases on the opposite strands”
NCERT Class 12 Biology, Ch. 9, p. 167, section 9.2.1
Tested in: NEET 2022 Q154
Learn it: rDNA Tools Restriction Ligase
DNA visualised by ethidium bromide under UV
Tested 3 times
“The separated DNA fragments can be visualised only after staining the DNA with a compound known as ethidium bromide followed by exposure to UV radiation”
NCERT Class 12 Biology, Ch. 9, p. 168, section 9.2.1
Tested in: NEET 2023 Q105, NEET 2022 Q111, NEET 2020 Q124
Learn it: rDNA Process PCR Blotting
Gel electrophoresis: smaller fragments move farther
“Since DNA fragments are negatively charged molecules they can be separated by forcing them to move towards the anode under an electric field”
NCERT Class 12 Biology, Ch. 9, p. 168, section 9.2.1
Tested in: NEET 2025 Q95
Learn it: rDNA Process PCR Blotting
PCR, blotting, electrophoresis
In short: PCR: denature 94°C → anneal 50-65°C → extend 72°C with Taq pol
NCERT Class 12 Biology, Ch. 9, p. 168, section 10.3
Tested in: NEET 2022 Q107
Learn it: rDNA Process PCR Blotting
Origin of replication (ori) controls copy number
“This is a sequence from where replication starts and any piece of DNA when linked to this sequence can be made to replicate within the host cells”
NCERT Class 12 Biology, Ch. 9, p. 169, section 9.2
Tested in: NEET 2020 Q115
Learn it: rDNA Tools Restriction Ligase
Cloning vector needs single restriction site
“…the vector needs to have very few, preferably single, recognition sites for the commonly used restriction enzymes”
NCERT Class 12 Biology, Ch. 9, p. 169, section 9.2
Tested in: NEET 2022 Q196
Learn it: rDNA Tools Restriction Ligase
Chromogenic substrate gives blue colonies, not DNA bands
Tested 3 times
“The presence of a chromogenic substrate gives blue coloured colonies if the plasmid in the bacteria does not have an insert”
NCERT Class 12 Biology, Ch. 9, p. 170, section 9.2.2
Tested in: NEET 2025 Q101, NEET 2025 Q173, NEET 2022 Q111
Learn it: rDNA Tools Restriction Ligase · rDNA Process PCR Blotting
Ti plasmid of Agrobacterium is tumour inducing
“The tumor inducing (Ti) plasmid of Agrobacterium tumifaciens has now been modified into a cloning vector which is no more pathogenic to the plants”
NCERT Class 12 Biology, Ch. 9, p. 170, section 9.2.2
Tested in: NEET 2024 Q167
Learn it: rDNA Tools Restriction Ligase
Gene gun/biolistics uses gold or tungsten particles
“…cells are bombarded with high velocity micro-particles of gold or tungsten coated with DNA in a method known as biolistics or gene gun”
NCERT Class 12 Biology, Ch. 9, p. 171, section 9.2.3
Tested in: NEET 2023 Q128
Learn it: Biotech Agriculture Bt GM
Chilled ethanol precipitates purified DNA
Tested 2 times
“…purified DNA ultimately precipitates out after the addition of chilled ethanol”
NCERT Class 12 Biology, Ch. 9, p. 171, section 9.3.1
Tested in: NEET 2023 Q117, NEET 2021 Q121
Learn it: rDNA Principles · Plant Kingdom
Bioreactors: large-scale culture with control systems
“To produce in large quantities, the development of bioreactors, where large volumes (100-1000 litres) of culture can be processed, was required”
NCERT Class 12 Biology, Ch. 9, p. 174, section 9.3.5
Tested in: NEET 2024 Q174
Learn it: rDNA Process PCR Blotting

Class 12, Chapter 10: Biotechnology and its Applications

Printed pages 177–187. 5 lines tested by 7 questions.

Topics in this chapter (3), in NCERT order

Biotech Agriculture Bt GMp. 1804 PYQs
Biotech Medicine Insulinp. 1829 PYQs
Transgenic Animals Biopiracyp. 1840 PYQs

RNAi silencing via complementary dsRNA
“This method involves silencing of a specific mRNA due to a complementary dsRNA molecule that binds to and prevents translation of the mRNA”
NCERT Class 12 Biology, Ch. 10, p. 180, section 10.1
Tested in: NEET 2025 Q131
Learn it: Biotech Agriculture Bt GM
Transposons as source of RNA triggering RNAi silencing
“The source of this complementary RNA could be from an infection by viruses having RNA genomes or mobile genetic elements (transposons) that replicate via an RNA intermediate”
NCERT Class 12 Biology, Ch. 10, p. 180, section 10.1
Tested in: NEET 2022 Q148
Learn it: rDNA Process PCR Blotting
Insulin C-peptide and A/B chain disulfide bonds
“This C peptide is not present in the mature insulin and is removed during maturation into insulin”
NCERT Class 12 Biology, Ch. 10, p. 182, section 10.2.1
Tested in: NEET 2021 Q169
Learn it: Biotech Medicine Insulin
Serum/urine analysis does not allow early diagnosis
“Using conventional methods of diagnosis (serum and urine analysis, etc.) early detection is”
NCERT Class 12 Biology, Ch. 10, p. 182, section 10.2.3
Tested in: NEET 2023 Q184
Learn it: Biotech Medicine Insulin
Biotech in medicine
Tested 3 times
In short: Recombinant insulin: Eli Lilly 1983 (Humulin) — A + B chains in E
NCERT Class 12 Biology, Ch. 10, p. 182, section 11.3
Tested in: NEET 2025 Q165, NEET 2022 Q190, NEET 2021 Q193
Learn it: Biotech Medicine Insulin

Class 12, Chapter 11: Organisms and Populations

Printed pages 188–204. 8 lines tested by 15 questions.

Topics in this chapter (2), in NCERT order

Population Attributes Growthp. 1948 PYQs
Population Interactionsp. 19712 PYQs

Population attributes: rates, sex ratio, age pyramid
“An individual may have births and deaths, but a population has birth rates and death rates”
NCERT Class 12 Biology, Ch. 11, p. 191, section 11.1.1
Tested in: NEET 2020 Q132
Learn it: Population Attributes Growth
Death rate is deaths per capita per period
“If 4 individuals in a laboratory population of 40 fruitflies died during a specified time interval, say a week, the death rate in the population during that period is 4/40 = 0.1 individuals per fruitfly per week”
NCERT Class 12 Biology, Ch. 11, p. 191, section 11.1.1
Tested in: NEET 2022 Q169
Learn it: Population Attributes Growth
Integral exponential growth equation Nt=N0ert
“…you can derive the integral form of the exponential growth equation as Nt = N0 ert where Nt = Population density after time t”
NCERT Class 12 Biology, Ch. 11, p. 194, section 11.1.2
Tested in: NEET 2021 Q140
Learn it: Population Attributes Growth
Population growth
Tested 3 times
In short: Exponential: dN/dt = rN
NCERT Class 12 Biology, Ch. 11, p. 194, section 12.4
Tested in: NEET 2025 Q112, NEET 2024 Q114, NEET 2023 Q187
Learn it: Population Attributes Growth
Population interactions
Tested 5 times
In short: Predation, competition (Gause's competitive exclusion principle), parasitism (+, −), mutualism (+, +
NCERT Class 12 Biology, Ch. 11, p. 197, section 12.5
Tested in: NEET 2025 Q178, NEET 2023 Q144, NEET 2022 Q120, NEET 2022 Q147, NEET 2021 Q135
Learn it: Population Interactions
Gause's Competitive Exclusion Principle
Tested 2 times
“Gause's 'Competitive Exclusion Principle' states that two closely related species competing for the same resources cannot co-exist indefinitely and the competitively inferior one will be eliminated eventually”
NCERT Class 12 Biology, Ch. 11, p. 199, section 11.1.4
Tested in: NEET 2024 Q186, NEET 2023 Q147
Learn it: Population Interactions
Resource partitioning avoids competition
“…species facing competition might evolve mechanisms that promote co-existence rather than exclusion. One such mechanism”
NCERT Class 12 Biology, Ch. 11, p. 199, section 11.1.4
Tested in: NEET 2021 Q128
Learn it: Population Interactions
Brood parasitism: cuckoo lays eggs in host nest
“Brood parasitism in birds is a fascinating example of parasitism in which the parasitic bird lays its eggs in the nest of its host and lets the host incubate them”
NCERT Class 12 Biology, Ch. 11, p. 200, section 11.1.4
Tested in: NEET 2023 Q185
Learn it: Population Interactions

Class 12, Chapter 12: Ecosystem

Printed pages 205–215. 5 lines tested by 8 questions.

Topics in this chapter (2), in NCERT order

Ecosystem Structure Functionp. 2064 PYQs
Ecosystem Productivity Decompositionp. 20711 PYQs

Productivity, decomposition, energy flow
Tested 4 times
In short: GPP > NPP (NPP = GPP − R)
NCERT Class 12 Biology, Ch. 12, p. 207, section 12.2
Tested in: NEET 2025 Q147, NEET 2024 Q143, NEET 2023 Q121, NEET 2020 Q113
Learn it: Ecosystem Productivity Decomposition
Productivity units: g/energy per area per year
“The rate of biomass production is called productivity”
NCERT Class 12 Biology, Ch. 12, p. 207, section 12.2
Tested in: NEET 2025 Q91
Learn it: Ecosystem Productivity Decomposition
Decomposition rate vs lignin/chitin content
“Bacterial and fungal enzymes degrade detritus into simpler inorganic substances. This process is called as catabolism”
NCERT Class 12 Biology, Ch. 12, p. 207, section 12.3
Tested in: NEET 2022 Q128
Learn it: Ecosystem Productivity Decomposition
Fragmentation, leaching, mineralisation steps
“Detritivores (e.g., earthworm) break down detritus into smaller particles. This process is called fragmentation”
NCERT Class 12 Biology, Ch. 12, p. 207, section 12.3
Tested in: NEET 2022 Q168
Learn it: Ecosystem Productivity Decomposition
Energy flow unidirectional; not exempt from 2nd law
“So you find unidirectional flow of energy from the sun to producers and then to consumers”
NCERT Class 12 Biology, Ch. 12, p. 209, section 12.4
Tested in: NEET 2025 Q108
Learn it: Ecosystem Productivity Decomposition

Class 12, Chapter 13: Biodiversity and Conservation

Printed pages 216–227. 12 lines tested by 12 questions.

Topics in this chapter (2), in NCERT order

Biodiversity Patternsp. 2195 PYQs
Biodiversity Loss Conservationp. 22410 PYQs

Robert May estimate: 7 million global species
“…a more conservative and scientifically sound estimate made by Robert May places the global species diversity at about 7 million”
NCERT Class 12 Biology, Ch. 13, p. 217, section 13.1.1
Tested in: NEET 2024 Q137
Learn it: Biodiversity Patterns
Amazon rain forest has greatest biodiversity on earth
“The largely tropical Amazonian rain forest in South America has the greatest biodiversity on earth”
NCERT Class 12 Biology, Ch. 13, p. 219, section 13.1.2
Tested in: NEET 2020 Q129
Learn it: Biodiversity Patterns
Why tropics show greatest species richness
“…tropical latitudes have remained relatively undisturbed for millions of years”
NCERT Class 12 Biology, Ch. 13, p. 219, section 13.1.2
Tested in: NEET 2024 Q127
Learn it: Biodiversity Patterns
Humboldt: species richness rises with area
“…the great German naturalist and geographer Alexander von Humboldt observed that within a region species richness increased with increasing explored area, but only up to a limit”
NCERT Class 12 Biology, Ch. 13, p. 220, section 13.1.2
Tested in: NEET 2024 Q137
Learn it: Biodiversity Patterns
Paul Ehrlich's rivet popper hypothesis
“…we can develop a proper perspective through an analogy (the ‘rivet popper hypothesis’) used by Stanford ecologist Paul Ehrlich”
NCERT Class 12 Biology, Ch. 13, p. 221, section 13.1.3
Tested in: NEET 2024 Q137
Learn it: Biodiversity Patterns
Tilman's outdoor-plot ecosystem experiments
“David Tilman’s long-term ecosystem experiments using outdoor plots provide some tentative answers”
NCERT Class 12 Biology, Ch. 13, p. 221, section 13.1.3
Tested in: NEET 2024 Q137
Learn it: Biodiversity Patterns
Dodo is an example of recent extinction
“Some examples of recent extinctions include the dodo (Mauritius), quagga (Africa), thylacine (Australia), Steller’s Sea Cow (Russia) and three subspecies (Bali, Javan, Caspian) of tiger”
NCERT Class 12 Biology, Ch. 13, p. 221, section 13.1.4
Tested in: NEET 2025 Q125
Learn it: Biodiversity Loss Conservation
Evil Quartet: four causes of biodiversity loss
Tested 4 times
“Causes of biodiversity losses: The accelerated rates of species extinctions that the world is facing now are largely due to human activities”
NCERT Class 12 Biology, Ch. 13, p. 222, section 13.1.4
Tested in: NEET 2025 Q125, NEET 2024 Q118, NEET 2023 Q104, NEET 2022 Q131
Learn it: Biodiversity Loss Conservation
Lantana is an invasive alien species
“…environmental damage caused and threat posed to our native species by invasive weed species like carrot grass (Parthenium), Lantana and water hyacinth (Eicchornia)”
NCERT Class 12 Biology, Ch. 13, p. 223, section 13.1.4
Tested in: NEET 2025 Q125
Learn it: Biodiversity Loss Conservation
Conservation
Tested 4 times
In short: In situ: national parks, biosphere reserves (e.g
NCERT Class 12 Biology, Ch. 13, p. 224, section 13.2
Tested in: NEET 2025 Q125, NEET 2025 Q171, NEET 2024 Q121, NEET 2022 Q118
Learn it: Biodiversity Loss Conservation
In situ vs ex situ conservation defined
“When we conserve and protect the whole ecosystem, its biodiversity at all levels is protected - we save the entire forest to save the tiger. This approach is called in situ (on site) conservation”
NCERT Class 12 Biology, Ch. 13, p. 224, section 13.2.2
Tested in: NEET 2022 Q173
Learn it: Biodiversity Loss Conservation
Earth Summit Rio 1992 Convention on Biological Diversity
“The historic Convention on Biological Diversity (‘The Earth Summit’) held in Rio de Janeiro in 1992, called upon all nations to take appropriate measures for conservation of biodiversity and sustainable utilisation of its benefits”
NCERT Class 12 Biology, Ch. 13, p. 225, section 13.2.2
Tested in: NEET 2023 Q108
Learn it: Biodiversity Loss Conservation

Class 12 (pre-2023 edition), Chapter 9: Strategies for Enhancement in Food Production

Printed pages 165–178. 5 lines tested by 4 questions. This chapter is not in the current (2023 rationalised) NCERT book; pages are from the pre-2023 edition.

Inbreeding raises homozygosity and accumulates superior genes
“Inbreeding increases homozygosity. Thus inbreeding is necessary if we want to evolve a pureline in any animal. Inbreeding exposes harmful recessive genes that are eliminated by selection”
NCERT Class 12 Biology (pre-2023 edition), Ch. 9, p. 167, section 9.1.2
Tested in: NEET 2023 Q200
Continued close inbreeding causes inbreeding depression
“…continued inbreeding, especially close inbreeding, usually reduces fertility and even productivity. This is called inbreeding depression”
NCERT Class 12 Biology (pre-2023 edition), Ch. 9, p. 167, section 9.1.2
Tested in: NEET 2023 Q200
Mutation breeding uses chemicals or gamma radiation
“Mutation is the process by which genetic variations are created through changes in the base sequence within genes”
NCERT Class 12 Biology (pre-2023 edition), Ch. 9, p. 174, section 9.2.2
Tested in: NEET 2021 Q134
Learn it: Mutations Genetic Disorders
SCP & tissue culture
In short: Single-cell protein: Spirulina, Methylophilus methylotrophus — protein source
NCERT Class 12 Biology (pre-2023 edition), Ch. 9, p. 176, section 8.5
Tested in: NEET 2024 Q106
Biofortification defined
“Biofortification – breeding crops with higher levels of vitamins and minerals, or higher protein and healthier fats – is the most practical means to improve public health”
NCERT Class 12 Biology (pre-2023 edition), Ch. 9, p. 176, section 9.2.4
Tested in: NEET 2022 Q165

Class 12 (pre-2023 edition), Chapter 16: Environmental Issues

Printed pages 270–286. 5 lines tested by 5 questions. This chapter is not in the current (2023 rationalised) NCERT book; pages are from the pre-2023 edition.

Electrostatic precipitator removes particulate matter
Tested 2 times
“…the most widely used of which is the electrostatic precipitator (Figure 16.1), which can remove over 99 per cent particulate matter present in the exhaust from a thermal power plant”
NCERT Class 12 Biology (pre-2023 edition), Ch. 16, p. 271, section 16.1
Tested in: NEET 2023 Q179, NEET 2022 Q102
Electrostatic precipitator mechanism
“It has electrode wires that are maintained at several thousand volts, which produce a corona that releases electrons”
NCERT Class 12 Biology (pre-2023 edition), Ch. 16, p. 271, section 16.1
Tested in: NEET 2023 Q179
Ozone thickness measured in Dobson units
“The thickness of the ozone in a column of air from the ground to the top of the atmosphere is measured in terms of Dobson units (DU)”
NCERT Class 12 Biology (pre-2023 edition), Ch. 16, p. 282, section 16.7
Tested in: NEET 2023 Q110
UV-B causes snow-blindness and skin cancer
“UV-B damages DNA and mutation may occur. It causes aging of skin, damage to skin cells and various types of skin cancers”
NCERT Class 12 Biology (pre-2023 edition), Ch. 16, p. 283, section 16.7
Tested in: NEET 2020 Q117
Montreal Protocol 1987 controls ozone depleters
“…an international treaty, known as the Montreal Protocol, was signed at Montreal (Canada) in 1987 (effective in 1989) to control the emission of ozone depleting substances”
NCERT Class 12 Biology (pre-2023 edition), Ch. 16, p. 283, section 16.7
Tested in: NEET 2020 Q101

Class 11 Biology (pre-2023 edition), Chapter 1

No line of this chapter is yet matched to a NEET question, but PrepBrix lessons teach from it. This chapter is not in the current (2023 rationalised) NCERT book; pages are from the pre-2023 edition.

Topics in this chapter (1), in NCERT order

What Is Livingp. 40 PYQs

Questions about this list

Which NCERT Biology lines has NEET asked about more than once?: 79 of the 348 lines on this page were tested by two or more questions. The most tested: Population interactions (NCERT Class 12 Biology, Ch. 11, p. 197; 5 questions, 2021, 2022, 2023, 2025); Productivity, decomposition, energy flow (NCERT Class 12 Biology, Ch. 12, p. 207; 4 questions, 2020, 2023, 2024, 2025); Conservation (NCERT Class 12 Biology, Ch. 13, p. 224; 4 questions, 2022, 2024, 2025); Evil Quartet: four causes of biodiversity loss (NCERT Class 12 Biology, Ch. 13, p. 222; 4 questions, 2022, 2023, 2024, 2025); Immunity (NCERT Class 12 Biology, Ch. 7, p. 134; 4 questions, 2020, 2022, 2024, 2025).
How were these NCERT lines chosen?: Each line is an NCERT Biology passage that a NEET question from 2020 to 2025 was matched to directly: the question can be answered from that line. 348 lines across 36 chapters, tied to 361 questions. The count covers the questions matched to our NCERT extract, which does not yet hold every page of the book, so a line missing here may still have been tested.
Which page numbers are these?: The page number printed in the NCERT book, not the page of a PDF file. Chapters are numbered as the current (2023 rationalised) edition prints them; a chapter that edition dropped is marked pre-2023 edition.
Which NCERT Biology chapter has the most lines NEET tested?: Molecular Basis of Inheritance (Class 12, Chapter 5): 25 lines, tied to 31 questions.

Question numbers are those of the test-booklet code we hold for each year (2020 H3, 2021 P3, 2022 R6, 2023 F3, 2024 Q3, 2025 47). Solve them on the Biology practice page, or go back to all Biology units. Found a mistake? It will be fixed and listed in the corrections log.

NCERT line-by-line Biology for NEET: the lines NEET tested

Class 11, Chapter 1: The Living World

Biodiversity

Taxonomic categories

Class 11, Chapter 2: Biological Classification

Body organisation across the five kingdoms (Table 2.1)

Cyanobacteria are autotrophic Monerans

Yeast used to make bread and beer

Criteria for classifying fungi into classes

Fungal sexual cycle: plasmogamy, karyogamy, meiosis

Rhizopus is a Phycomycete (bread mould)

Ascomycetes (Penicillium) form conidia asexually

Agaricus, Ustilago, Puccinia are Basidiomycetes

Class 11, Chapter 3: Plant Kingdom

Hydrocolloids: algin (brown), carrageen (red)

Phaeophyceae: reproduction, pigments, cell wall

Bryophytes

Bryophyte life cycle sequence

Liverwort gemmae: asexual reproduction

Strobili or cones in pteridophytes

Pteridophyte spores form by meiosis

Heterosporous pteridophytes: Selaginella, Salvinia

Pteridophyte prothallus and fertilisation

Gymnosperms

Gymnosperm pollen tube grows to archegonia

Class 11, Chapter 4: Animal Kingdom

Coelenterates, ctenophores, echinoderms are radial

Coelomate, pseudocoelomate, acoelomate defined

Physalia is the Portuguese man-of-war

Pleurobrachia is an example of Ctenophora

Ancylostoma is the hookworm (Aschelminthes)

Arthropoda

Limulus (King crab) is a living fossil

Radula is Mollusca's rasping feeding organ

Pinctada is the pearl oyster (Mollusca)

Water vascular system: locomotion, feeding, respiration

Hemichordates are bilaterally symmetrical

Stomochord is Hemichordata's notochord-like structure

Vertebrates are chordates; notochord replaced

Chordates have closed circulation, gill slits

Table 4.1 chordate vs non-chordate features

Myxine (Hagfish) is a Cyclostomata example

All Cyclostomata are ectoparasites

Pristis (Saw fish) is a Chondrichthyes example

Air bladder regulates buoyancy in Osteichthyes

Exocoetus, Pterophyllum are Osteichthyes examples

Mammary glands, hair, pinnae unique to mammals

Class 11, Chapter 5: Morphology of Flowering Plants

Fibrous roots originate from stem base

Flower is a modified shoot with floral meristem

Zygomorphic flower examples

Actinomorphic flower examples

Epigynous flowers have inferior ovary

Perigynous flower: half inferior ovary

Vexillary aestivation in pea and bean

Twisted aestivation: china rose, lady's finger, cotton

Stamen fusion types: mono/di/polyadelphous

Axile placentation: china rose, tomato, lemon

Drupe fruit: mango and coconut

Class 11, Chapter 6: Anatomy of Flowering Plants

Radial vascular bundle arrangement in roots

Monocot root has polyarch xylem bundles

Monocot stem: sclerenchymatous hypodermis, no phloem parenchyma

Dicot vs monocot stem (TS)

Flaccid bulliform cells curl monocot leaves inward

Class 11, Chapter 7: Structural Organisation in Animals

Animal tissues

Male frog copulatory pad on forelimb first digit

Frog respiration differs in water vs on land

Frog vena cava and portal systems

Class 11, Chapter 8: Cell — The Unit of Life

Reductionist Biology (Unit 3 opener)

Prokaryotic vs eukaryotic

Mesosome: functions in prokaryotic cell

Inclusion bodies are unbound, free in cytoplasm

Cell Membrane composition

Active transport across the membrane

Endomembrane system

Golgi apparatus: cis-face intake, trans-face release

Mitochondria and plastids