Post-fertilization events in angiosperms follow a predictable sequence that NEET tests through precise terminology. The high-frequency confusion here: mixing up what the ovule becomes versus what the ovary becomes, and misattributing endosperm ploidy.
The sequence after double fertilization:
The zygote (2n) undergoes repeated mitotic divisions to form the embryo. The primary endosperm nucleus (PEN, 3n — from triple fusion) divides faster than the zygote, forming endosperm that nourishes the developing embryo.
Seed formation: The ovule matures into the seed. The integuments become the seed coat (testa from outer, tegmen from inner integument). The nucellus is generally consumed, but persists as perisperm in some seeds (e.g., black pepper, beet).
Fruit formation: The ovary wall develops into the pericarp (fruit wall). Fruits formed from the ovary alone = true fruits. Fruits where thalamus or other floral parts contribute = false fruits (e.g., apple — thalamus forms fleshy part; strawberry — thalamus forms receptacle).
Parthenocarpy: Fruit development without fertilization — seedless fruits. Distinct from apomixis (seed formation without fertilization).
Key NEET watch-out: Endosperm is 3n (triploid) in most angiosperms because it results from fusion of two polar nuclei (n + n) with one male gamete (n). Students who write "2n" lose marks immediately. Also: in monocots, endosperm persists (albuminous seeds); in most dicots, it is consumed during embryo development (exalbuminous seeds).
NCERT Class 12 Biology Chapter 1, page 18 confirms these structural transformations as core evaluable content retained under the rationalized syllabus.
Select an option to see the explanation. Wrong answers show why your choice was tempting — and name the exact trap it exploits.
The triploid (3n) structure in a mature angiosperm seed is the:
Answer: D. Endosperm is 3n because it forms from triple fusion — two polar nuclei (n + n) fuse with one male gamete (n). NCERT Class 12 Biology Chapter 1, page 18.
Why A is wrong: A — The embryo is diploid (2n), formed from the zygote after syngamy of one male gamete with the egg cell.
Why B is wrong: B — The nucellus is pre-existing maternal tissue (2n); it is consumed during seed development or persists as perisperm.
Why C is wrong: C — The seed coat develops from integuments (maternal tissue, 2n) and is not a product of fertilization.
Which of the following is an example of a false fruit?
Answer: B. In apple, the thalamus contributes to the fleshy edible part, making it a false fruit (pseudocarp). The true fruit (from the ovary) is the core. NCERT Class 12 Biology Chapter 1.
Why A is wrong: A — Mango is a true fruit; the edible part is the mesocarp of the pericarp, derived entirely from the ovary wall.
Why C is wrong: C — Tomato is a true fruit (berry type); the entire fleshy part develops from the ovary.
Why D is wrong: D — Pea is a true fruit (legume/pod); the pod is the pericarp derived from the ovary wall.
Seedless fruits can be produced by the phenomenon of:
Answer: C. Parthenocarpy is fruit development without fertilization, producing seedless fruits. Apomixis produces seeds without fertilization — a common confusion. NCERT Class 12 Biology Chapter 1.
Why A is wrong: A — Apomixis produces seeds WITHOUT fertilization (asexual seed formation), not seedless fruits. This is the most common NEET trap — apomixis = seeds present; parthenocarpy = no seeds.
Why B is wrong: B — Polyembryony means multiple embryos within a single seed (e.g., citrus). Seeds are still present.
Why D is wrong: D — Triple fusion is a normal event in double fertilization that produces the triploid endosperm nucleus. It leads to seeded fruits, not seedless ones.
In angiosperms, the__(i)__ develops into the seed and the __(ii)__ develops into the fruit.
Answer: A. The ovule (containing embryo sac) matures into the seed after fertilization. The ovary wall develops into the pericarp (fruit). This is a high-frequency assertion-based question in NEET. NCERT Class 12 Biology Chapter 1, page 20.
Why B is wrong: B — This reverses the mapping. The ovary becomes the fruit, not the seed. A common trap exploiting quick-reading habits.
Why C is wrong: C — The zygote becomes the embryo within the seed, not the entire seed. The seed includes seed coat (from integuments) and endosperm as well.
Why D is wrong: D — The nucellus is generally consumed during seed development (or becomes perisperm). Integuments become the seed coat, not the fruit.
A pea pod develops entirely from the ovary wall, and its mature seeds store food in fully developed cotyledons with no residual endosperm. Based on these two observations together, pea is correctly classified as a:
Answer: C. Two independent classifications must be combined here. First, since the pod (pericarp) develops solely from the ovary wall with no contribution from the thalamus or other floral parts, pea is a true fruit. Second, since its mature seed retains no endosperm — food is stored entirely in fully developed cotyledons — it is an exalbuminous seed (e.g., pea, groundnut). Combining both gives: true fruit with exalbuminous seeds (NCERT Class 12 Biology Chapter 1, page 20).
Why A is wrong: This gets the fruit type right (pea's pod is from the ovary wall alone, so it is a true fruit) but wrongly calls the seed albuminous — pea seeds consume their endosperm during development and store food in the cotyledons instead, which defines an exalbuminous seed, not albuminous (trap: reversing the endosperm-retention criterion).
Why B is wrong: This keeps the correct fruit type (true fruit) but pairs it with the wrong seed type: albuminous seeds RETAIN endosperm at maturity (e.g., wheat, castor), whereas pea's fully developed cotyledons with no residual endosperm is the defining feature of an exalbuminous seed (trap: swapping albuminous/exalbuminous).
Why D is wrong: This gets the seed type right (exalbuminous, since cotyledons store the food and no endosperm remains) but wrongly calls pea a false fruit — a false fruit requires the thalamus or another floral part (as in apple) to contribute to the fruit, which does not happen in pea; the pod is pericarp derived purely from the ovary wall, making it a true fruit (trap: reversing the true/false fruit criterion).
An albuminous seed is one that retains:
Answer: C. Albuminous (endospermic) seeds retain endosperm at maturity as the food reserve (e.g., wheat, maize, castor). In exalbuminous seeds (e.g., pea, groundnut), the endosperm is consumed and food is stored in cotyledons.
Why A is wrong: A — Perisperm (residual nucellus) is a separate structure. Seeds with perisperm are not called 'albuminous' — that term specifically refers to endosperm retention.
Why B is wrong: B — Fully developed cotyledons storing food characterize exalbuminous seeds, where endosperm was consumed during development. This is the opposite situation.
Why D is wrong: D — Integuments become seed coat in all seeds; this is not the defining feature of albuminous seeds.
In a fertilized ovule, the outer integument develops into:
Answer: A. Outer integument → testa (outer seed coat). Inner integument → tegmen (inner seed coat). This is a direct structural mapping question. NCERT Class 12 Biology Chapter 1.
Why B is wrong: B — Tegmen develops from the INNER integument, not the outer. This swap is a high-frequency NEET distractor.
Why C is wrong: C — Perisperm develops from the nucellus (when it persists), not from integuments.
Why D is wrong: D — Pericarp develops from the ovary wall, not from the ovule's integuments. Pericarp is a fruit structure, not a seed structure.
A student claims that in coconut, the liquid endosperm represents free nuclear endosperm that did not undergo cellularization. In which type of endosperm development does cellularization follow the free nuclear stage?
Answer: D. In nuclear type endosperm development, the PEN divides repeatedly without cell wall formation (free nuclear stage), and cell walls are laid down later. Coconut water is the free nuclear endosperm; the white kernel is the cellularized portion. This is the most common type in angiosperms.
Why A is wrong: A — This is incorrect because cellularization DOES eventually occur in nuclear type endosperm. The coconut example proves it: free nuclear endosperm (water) + cellularized endosperm (white meat) coexist.
Why B is wrong: B — In cellular type, every nuclear division is immediately followed by cytokinesis. There is NO free nuclear stage at all — cell walls form from the very first division.
Why C is wrong: C — Helobial type is intermediate: the first division produces two unequal chambers (one behaves nuclear-type, other cellular-type). It does not describe the standard free-nuclear-then-cellularize pattern asked here.
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Given
A NEET question states: "Assertion: The__(i)__ of an angiosperm seed develops from the__(ii)__." Match the blanks with the options provided:• (A) (i) Seed coat — (ii) Integuments• (B) (i) Fruit wall — (ii) Ovule• (C) (i) Endosperm — (ii) Zygote• (D) (i) Perisperm — (ii) Endosperm
Required
Identify which option correctly maps the post-fertilization structural origin.
Concept
After double fertilization, each structure in the ovule has a defined developmental fate:• Ovule → Seed• Integuments → Seed coat (testa + tegmen)• Zygote → Embryo• PEN (3n) → Endosperm• Ovary wall → Pericarp (fruit wall)• Nucellus → consumed (or perisperm if persistent)
Formula
No formula applies. This is a structural-mapping recall question.
Substitution
Check each option against the mapping:• (A) Seed coat from integuments ✓ — matches exactly• (B) Fruit wall from ovule ✗ — fruit wall is from ovary wall• (C) Endosperm from zygote ✗ — endosperm is from PEN (triple fusion)• (D) Perisperm from endosperm ✗ — perisperm is from nucellus
Calculation
No arithmetic. Elimination by structural origin verification.
Final answer
(A) — The seed coat develops from the integuments.
Common trap
Option (C) is the most tempting wrong answer. Students confuse the two products of double fertilization: syngamy produces the zygote (→ embryo), while triple fusion produces the PEN (→ endosperm). Attributing endosperm to the zygote conflates these two parallel events.
Similar NEET-style question
"In a post-fertilization angiosperm ovule, the nucellus persists as ________ in some seeds." Answer: perisperm (e.g., black pepper). Distractor trap: students select "endosperm" because both are nutritive tissues.
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Endosperm: nuclear → cellular. Embryo: zygote → proembryo → globular → heart → torpedo (dicot) / coleoptile + coleorhiza (monocot). Seed coat from integuments. Fruit: pericarp from ovary wall.
-- NCERT Class 12 Biology, Ch. 1, p. 18More in Reproduction: 10 exam traps and mistakes · 1 question pattern from its other lessons.
4 questions from NEET 2025, 2026. Answers verified against NTA official keys.
Which of the following plant produces non-albuminous seeds ?
Page numbers are the ones printed in the current NCERT textbook (2023 rationalised edition), unless marked pre-2023. The books are free at ncert.nic.in.
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