Families Fabaceae Solanaceae

8 MCQs9-step worked example
Source: NCERT Biological ClassificationPYQ coverage: NEET 2020, 2021, 2022, 2023, 2024, 2025Official key: NTA-verifiedLast reviewed: May 2026

Lesson

The trap that costs marks: NEET repeatedly asks you to match a plant family with its floral formula, placentation type, or fruit type — and the distractors swap features between Fabaceae, Solanaceae, and Liliaceae. The high-frequency confusion is placentation: Fabaceae is marginal, Solanaceae is axile, and Liliaceae is axile — students merge the last two or assign parietal (which belongs to Brassicaceae).

Three families, locked features:

Fabaceae (Papilionaceae) — Floral formula: % ⚥ K(5) C1+2+(2) A(9)+1 G1. Aestivation: vexillary (descending imbricate). Androecium: diadelphous (9 fused + 1 free). Gynoecium: monocarpellary, superior ovary, marginal placentation. Fruit: legume. Examples: pea, gram, soybean.

Solanaceae — Floral formula: ⊕ ⚥ K(5) C(5) A5 G(2). Aestivation: valvate (calyx), twisted (corolla in Datura). Androecium: epipetalous (5 stamens attached to petals). Gynoecium: bicarpellary, syncarpous, superior, axile placentation. Fruit: berry or capsule. Examples: tomato, potato, petunia, Datura.

Liliaceae — Floral formula: ⊕ ⚥ P(3+3) A3+3 G(3). Perianth: tepals (not differentiated into calyx/corolla), 6 in two whorls. Androecium: 6 stamens in two whorls. Gynoecium: tricarpellary, syncarpous, superior, axile placentation. Fruit: capsule or berry. Examples: Allium (onion), Colchicum, lily.

Watch-out: When you see "axile placentation + superior ovary," do NOT auto-select Solanaceae — Liliaceae shares both features. The differentiator is perianth structure: tepals (undifferentiated) = Liliaceae; distinct calyx + corolla = Solanaceae.

(Reference: NCERT Class 11 Biology Chapter 5, page 96)

Practice MCQs

Select an option to see the explanation. Wrong answers show why your choice was tempting — and name the exact trap it exploits.

MCQ 1Easy RecallPractice

The floral formula % ⚥ K(5) C1+2+(2) A(9)+1 G1 represents which family?

MCQ 2Easy RecallPractice

Which type of aestivation is characteristic of the corolla in Fabaceae?

MCQ 3Easy RecallPractice

Placentation in Solanaceae is:

MCQ 4Concept TrapPractice

Which of the following is a distinguishing feature of Liliaceae that separates it from Solanaceae?

MCQ 5Direct ApplicationPractice

The androecium in Solanaceae is described as epipetalous because:

MCQ 6Direct ApplicationPractice

A student identifies a plant with the following features: monocarpellary ovary, marginal placentation, diadelphous stamens, and legume fruit. The plant belongs to:

MCQ 7Direct ApplicationPractice

Which of the following correctly matches the plant with its family and fruit type?

MCQ 8Easy RecallPractice

In Liliaceae, the number of stamens and their arrangement is:

Worked Example

  1. 1

    Given

    A NEET question presents a plant with: zygomorphic flower, papilionaceous corolla with vexillary aestivation, diadelphous stamens (9)+1, monocarpellary superior ovary, marginal placentation. The question asks to identify the family.

  2. 2

    Required

    Identify the plant family based on the combination of floral characters.

  3. 3

    Concept

    Each angiosperm family has a diagnostic combination of floral features. The key is matching ALL features simultaneously — no single feature is sufficient because families can share individual characters.

  4. 4

    Formula/Rule

    Diagnostic matrix: - Fabaceae: zygomorphic + vexillary + diadelphous + monocarpellary + marginal + legume - Solanaceae: actinomorphic + valvate/twisted + epipetalous + bicarpellary + axile + berry/capsule - Liliaceae: actinomorphic + tepals (P3+3) + 6 free stamens + tricarpellary + axile + capsule/berry

  5. 5

    Substitution/Matching

    Given features → checklist: - Zygomorphic ✓ → eliminates Solanaceae (actinomorphic) and Liliaceae (actinomorphic) - Vexillary aestivation ✓ → confirms papilionaceous = Fabaceae - Diadelphous (9)+1 ✓ → Fabaceae diagnostic - Monocarpellary + marginal ✓ → Fabaceae (Solanaceae is bicarpellary axile)

  6. 6

    Reasoning

    All five features align exclusively with Fabaceae. No other family has this combination. The strongest eliminators are symmetry (zygomorphic rules out Solanaceae/Liliaceae immediately) and placentation type (marginal rules out any axile/parietal family).

  7. 7

    Final answer

    **Family: Fabaceae (Papilionaceae)**

  8. 8

    Common trap

    The distractor "Solanaceae" tempts students who focus only on "superior ovary" (shared by all three families) without checking symmetry and placentation. Another trap: confusing "imbricate" with "vexillary" — vexillary IS a type of imbricate, but it's specifically diagnostic for Fabaceae.

  9. 9

    Similar NEET-style question

    "A plant shows actinomorphic flowers, gamopetalous corolla with 5 epipetalous stamens, bicarpellary syncarpous superior ovary with axile placentation. Identify the family." (Answer: Solanaceae — actinomorphic + gamopetalous + epipetalous + bicarpellary axile is the Solanaceae diagnostic set.) ---

Before solving, remember these

Key Fact

Fabaceae, Solanaceae, Liliaceae

Fabaceae (pea): zygomorphic, papilionaceous corolla, marginal placentation, fruit legume. Solanacaeae (potato): actinomorphic, axile placentation, fruit berry/capsule. Liliaceae (onion): trimerous, axile, fruit capsule/berry.

-- NCERT Class 11 Biology, Ch. 5, p. 96

Exam Traps & Common Mistakes

These are the exact patterns that cause wrong answers in NEET. Each trap includes when it triggers and how to avoid it.

Trap

Dicot vs monocot stem feature confusion

Category: Similar Terms

Dicot stem: vascular bundles in ring, conjoint, OPEN (cambium present), endarch. Monocot: scattered, CLOSED (no cambium), endarch.

When it triggers

Question shows TS or asks bundle arrangement.

How to avoid

Ring + cambium = dicot (open); scattered + no cambium = monocot (closed).

Trap

Epithelial tissue type and location swap

Category: Similar Terms

Squamous (alveoli, blood vessel lining), cuboidal (kidney tubules), columnar (intestine), ciliated (trachea/bronchi), glandular (sweat).

When it triggers

Question gives location and asks tissue type or vice versa.

How to avoid

Map: shape → function — squamous = thin diffusion; columnar = absorption; ciliated = movement.

Trap

Placentation type confusion (axile vs parietal)

Category: Similar Terms

Marginal (peas), axile (china rose, lemon), parietal (mustard), free central (Dianthus), basal (sunflower).

When it triggers

Question gives plant family/example and asks placentation.

How to avoid

Memorise per family: Solanaceae axile; Brassicaceae parietal; Fabaceae marginal.

Mistake

Confuses valvate, twisted, and imbricate aestivation.

Root cause: term confusion

Correction

Valvate: edges touch (Calotropis). Twisted: one edge overlaps next (China rose). Imbricate: irregular overlap (Cassia). Vexillary: papilionaceous (pea — flag-like standard).

Past Year Questions

47 questions from NEET 2020, 2021, 2022, 2023, 2024, 2025. Answers verified against NTA official keys.

NEET 2024

Bulliform cells are responsible for

1Inward curling of leaves in monocots.
2Protecting the plant from salt stress.
3Increased photosynthesis in monocots.
4Providing large spaces for storage of sugars.
NTA Answer: Option 1(final)
NEET 2024

Match List I with List II related to digestive system of cockroach. List-I List-II A. The structures used for I. Gizzard storing of food. B. Ring of 6-8 blind tubules II. Gastric Caeca at junction of foregut and midgut. C. Ring of 100-150 yellow III. Malpighian tubules coloured thin filaments at junction of midgut and hindgut. - 51 - NEET (UG)-2024 (Code-Q3) D. The structures used for IV. Crop grinding the food. Choose the correct answer from the options given below:

1A-IV, B-II, C-III, D-I
2A-I, B-II, C-III, D-IV
3A-IV, B-III, C-II, D-I
4A-III, B-II, C-IV, D-I
NTA Answer: Option 1(final)
NEET 2023

Given below are two statements : Statement I : Endarch and exarch are the terms often used for describing the position of secondary xylem in the plant body. Statement II : Exarch condition is the most common feature of the root system. In the light of the above statements, choose the correct answer from the options given below:

1Both Statement I and Statement II are false
2Statement I is correct but Statement II is false
3Statement I is incorrect but Statement II is true
4Both Statement I and Statement II are true
NTA Answer: Option 3(final)
NEET 2023

Given below are two statements : Statement I : The forces generated transpiration can lift a xylem-sized column of water over 130 meters height. Statement II : Transpiration cools leaf surfaces sometimes 10 to 15 degrees evaporative cooling. In the light of the above statements, choose the most appropriate answer from the options given below :

1Both Statement I and Statement II are incorrect
2Statement I is correct but Statement II is incorrect
3Statement I is incorrect but Statement II is correct
4Both Statement I and Statement II are correct
NTA Answer: Option 4(final)
NEET 2023

Given below are two statements : One is labelled as Assertion A and the other is labelled as Reason R : Assertion A : Late wood has fewer xylary elements with narrow vessels. Reason R : Cambium is less active in winters. In the light of the above statements, choose the correct answer from the options given below :

1Both A and R are true but R is NOT the correct explanation of A
2A is true but R is false
3A is false but R is true
4Both A and R are true and R is the correct explanation of A
NTA Answer: Option 4(final)
NEET 2023

Match List I with List II. List I (Type of Joint) List II (Found between) A. Cartilaginous Joint I. Between flat skull bones B. Ball and Socket Joint II. Between adjacent vertebrae in vertebral column C. Fibrous Joint III. Between carpal and metacarpal of thumb D. Saddle Joint IV. Between Humerus and Pectoral girdle Choose the correct answer from the options given below:

1A-II, B-IV, C-I, D-III
2A-I, B-IV, C-III, D-II
3A-II, B-IV, C-III, D-I
4A-III, B-I, C-II, D-IV
NTA Answer: Option 1(final)
NEET 2023

Which of the following statements are correct regarding skeletal muscle? A. Muscle bundles are held together by collagenous connective tissue layer called fascicle. B. Sarcoplasmic reticulum of muscle fibre is a store house of calcium ions. C. Striated appearance of skeletal muscle fibre is due to distribution pattern of actin and myosin proteins. D. M line is considered as functional unit of contraction called sarcomere. Choose the most appropriate answer from the options given below:

1B and C only
2A, C and D only
3C and D only
4A, B and C only
NTA Answer: Option 1(final)
NEET 2022

Read the following statements about the vascular bundles : (a) In roots, xylem and phloem in a vascular bundle are arranged in an alternate manner along the different radii. (b) Conjoint closed vascular bundles do not possess cambium (c) In open vascular bundles, cambium is present in between xylem and phloem (d) The vascular bundles of dicotyledonous stem possess endarch protoxylem (e) In monocotyledonous root, usually there are more than six xylem bundles present Choose the correct answer from the options given below :

1(a), (c), (d) and (e) Only
2(a), (b) and (d) Only
3(b), (c), (d) and (e) Only
4(a), (b), (c) and (d) Only Answer (NA) No option is correct 106. DNA polymorphism forms the basis of : (1) Translation (2) Genetic mapping (3) DNA finger printing (4) Both genetic mapping and DNA finger printing
NTA Answer: Option 4(final)
NEET 2022

In old trees the greater part of secondary xylem is dark brown and resistant to insect attack due to : (a) secretion of secondary metabolities and their deposition in the lumen of vessels. (b) deposition of organic compounds like tannins and resins in the central layers of stem. (c) deposition of suberin and aromatic substances in the outer layer of stem. (d) deposition of tannins, gum, resin and aromatic substances in the peripheral layers of stem. (e) presence of parenchyma cells, functionally active xylem elements and essential oils. Choose the correct answer from the options given below:

1(b) and (d) Only
2(a) and (b) Only
3(c) and (d) Only
4(d) and (e) Only
NTA Answer: Option 2(final)
NEET 2022

The anatomy of springwood shows some peculiar features. Identify the correct set of statements about springwood. (a) It is also called as the earlywood (b) In spring season cambium produces xylem elements with narrow vessels (c) It is lighter in colour (d) The springwood along with autumnwood shows alternate concentric rings forming annual rings (e) It has lower density Choose the correct answer from the options given below :

1(c), (d) and (e) Only
2(a), (b), (d) and (e) Only
3(a), (c), (d) and (e) Only
4(a), (b) and (d) Only
NTA Answer: Option 3(final)
NEET 2022

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Osteoporosis is characterised by decreased bone mass and increased chance of fractures. Reason (R): Common cause of osteoporosis is increased levels of estrogen. In the light of the above statements, choose the most appropriate answer from the options given below.

1(A) is not correct but (R) is correct
2Both (A) and (R) are correct and (R) is the correct explanation of (A)
3Both (A) and (R) are correct but (R) is not the correct explanation of (A)
4(A) is correct but (R) is not correct
NTA Answer: Option 4(final)
NEET 2022

Given below are two statements: Statements I : In a scrubber the exhaust from the thermal plant is passed through the electric wires to charge the dust particles. Statement II : Particulate matter (PM 2.5) cannot be removed by scrubber but can be removed by an electrostatic precipitator. In the light of the above statements, choose the most appropriate answer from the options given below :

1Statement I is incorrect but Statement II is correct
2Both Statement I and Statement II are correct
3Both Statement I and Statement II are incorrect
4Statement I is correct but Statement II is incorrect
NTA Answer: Option 1(final)
NEET 2021

Match List-I with List-II. (4) Extension, Denaturation, Annealing Answer (2) List-I List-II 116. When gene targetting involving gene amplification is (a) Lenticels (i) Phellogen attempted in an individual's tissue to treat disease, (b) Cork cambium (ii) Suberin deposition it is known as :

1Safety testing (c) Secondary cortex (iii) Exchange of gases
2Biopiracy (d) Cork (iv) Phelloderm
3Gene therapy Choose the correct answer from the options given
4Molecular diagnosis below.
NTA Answer: Option 3(final)
NEET 2021

Match Column-I with Column-II (a) % K C A G (i) Brassicaceae 150. Now a days it is possible to detect the mutated gene (5) 1+2+(2) (9)+1 1 causing cancer by allowing radioactive probe to (b) K (5) C (5) A 5 G 2 (ii) Liliaceae hybridise its complimentary DNA in a clone of cells, followed by its detection using autoradiography (c) P A G (iii) Fabaceae because : (3 + 3) 3 + 3 (3)

1mutated gene does not appear on photographic (d) K C A G (iv) Solanaceae 2 + 2 4 2 – 4
2film as the probe has complementarity with it Select the correct answer from the options given (2) mutated gene partially appears on a below. photographic film (a) (b) (c) (d)
3mutated gene completely and clearly appears on (1) (iv) (ii) (i) (iii) a photographic film (2) (iii) (iv) (ii) (i)
4mutated gene does not appear on a (3) (i) (ii) (iii) (iv) photographic film as the probe has no complementarity with it (4) (ii) (iii) (iv) (i)
NTA Answer: Option 4(final)
NEET 2020

ÁŸêŸ Sà ÷Ê ∑§Ê Á◊‹ÊŸ ∑§⁄U ‚„Ë Áfl∑§À¬ ∑§Ê øÿŸ ∑§⁄UÊ – second and Sà ÷ - I Sà ÷ - II seventh ribs (a) å‹ÊflË ¬‚Á‹ÿÊ° (i) ŒÍ‚⁄UË ∞fl ‚ÊÃflË (b) Acromion (ii) Head of the ¬‚‹Ë ∑ § ’Ëø ÁSÕà Humerus „Ê ÃË „Ò (c) Scapula (iii) Clavicle (b) ∞∑§˝ÊÁ ◊ÿŸ (ii) sÍ◊⁄U‚ ∑§Ê ‡ÊË ¸ (c) S∑Ò§¬È‹Ê (iii) Ä‹ Áfl∑§‹ (d) Glenoid cavity (iv) Do not connect (d) Ç‹ËŸÊÚÿ«U ªÈ„Ê (iv) ©⁄UÊ ÁSÕ ‚ Ÿ„Ë ¡È«∏ÃË with the sternum (a) (b) (c) (d) (a) (b) (c) (d)

1(iv) (iii) (i) (ii) (1) (iv) (iii) (i) (ii)
2(ii) (iv) (i) (iii) (2) (ii) (iv) (i) (iii)
3(i) (iii) (ii) (iv) (3) (i) (iii) (ii) (iv)
4(iii) (ii) (iv) (i) (4) (iii) (ii) (iv) (i) H3 28 Hindi+English
NTA Answer: Option 1(final)

How NEET usually asks this

Recurring question shapes from past papers. Each pattern shows why wrong options look tempting.

Sources

NCERT refs: Class 11 Biology Chapter 5, p.96

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