Class 12 Biology | Unit I — Reproduction
Chapter 2: Sexual Reproduction in Flowering Plants
Flower Structure • Microsporogenesis • Megasporogenesis • Pollination • Double Fertilisation • Endosperm • Fruit & Seed
1. The Flower — A Site for Sexual Reproduction
Flower: A modified shoot bearing reproductive organs. In angiosperms, it is the site of
sexual reproduction. Complete flower has: calyx, corolla, androecium, gynoecium. Incomplete flower lacks one
or more whorls.
1.1 Androecium (Male Reproductive Organ)
- Each stamen = filament + anther.
- Anther: typically bilobed, each lobe has 2 microsporangia = 4 microsporangia per anther (tetrasporangiate).
- Wall of microsporangium (outside to inside): Epidermis → Endothecium → Middle layers → Tapetum.
- Tapetum: innermost nutritive layer. Provides nutrients to developing pollen grains. Has dense cytoplasm; polynucleate.
1.2 Microsporogenesis
Microsporogenesis: Process of formation of microspores (pollen grains) from microspore
mother cells (MMC / pollen mother cells, 2n) by meiosis.
- MMC (2n) divides by meiosis → tetrad of microspores (n).
- Each microspore = pollen grain.
- Pollen grains are surrounded by exine (outer, sporopollenin — most resistant biological material known) and intine (inner, cellulose + pectin).
- Sporopollenin: resistant to extreme heat, strong acids/alkalis, decay. Hence pollen preserved in fossil record. Hence allergy persists.
- Pollen grain has germ pore (aperture in exine where intine bulges out on germination).
- Mature pollen: 2-celled — large vegetative (tube) cell + small generative cell. OR 3-celled if generative divides before shedding.
1.3 Gynoecium (Female Reproductive Organ)
- Pistil = Stigma + Style + Ovary.
- Monocarpellary: single pistil (pea). Syncarpous: fused pistils (tomato). Apocarpous: free pistils (lotus).
- Ovary contains ovule(s) attached to ovary wall via funicle at hilum.
1.4 Parts of an Ovule
| Part | Structure / Function |
|---|---|
| Funicle | Stalk attaching ovule to ovary wall. |
| Hilum | Junction of funicle and ovule body. |
| Integuments | 1 or 2 protective layers around ovule. Inner integument = inner; outer integument = outer. Leave a small opening = micropyle. |
| Nucellus | Nutritive tissue inside integuments; encloses embryo sac. |
| Chalaza | Region opposite micropyle where nucellus and integuments fuse. |
| Embryo sac | Female gametophyte; located inside nucellus. |
1.5 Megasporogenesis and Embryo Sac Formation
Megasporogenesis: Formation of megaspores from megaspore mother cell (MMC, 2n) by
meiosis → 4 megaspores (n). In most angiosperms, only 1 megaspore functional
(chalazal end); remaining 3 degenerate. Called monosporic development.
- Functional megaspore undergoes 3 mitotic divisions (free nuclear) → 8-nucleate embryo sac (Polygonum type).
- Cell arrangement of mature embryo sac (8-nucleate, 7-celled):
| Position | Cells | Function |
|---|---|---|
| Micropylar end | Egg cell + 2 synergids = Egg apparatus | Egg cell = female gamete. Synergids have filiform apparatus; guide pollen tube. |
| Centre | Central cell with 2 polar nuclei | Polars fuse to form secondary nucleus (2n). Fertilised to form endosperm. |
| Chalazal end | 3 antipodal cells | Nutritive; degenerate after fertilisation. |
⚠️ NEET Focus (2013, 2015, 2017, 2019, 2021): Anther = 4
microsporangia. Tapetum = nutritive layer. Sporopollenin = most resistant. Exine =
sporopollenin; intine = cellulose. Embryo sac = 8-nucleate, 7-celled. Egg apparatus = egg +
2 synergids. Polar nuclei = 2 (central cell). Antipodals = 3. Monosporic development = 1
functional megaspore (chalazal).
2. Pollination
Pollination: Transfer of pollen grains from anther to stigma. If same flower or same plant
= self-pollination (autogamy). If different plant of same species =
cross-pollination (xenogamy / allogamy).
2.1 Agents of Pollination
| Agent | Term | Adaptations / Examples |
|---|---|---|
| Wind | Anemophily | Feathery stigma, large amounts of light dry pollen, reduced/absent perianth, exposed anthers. Examples: maize, date palm, grasses, coconut. |
| Water | Hydrophily | Pollen light/mucilage-covered. Ribbon-like pollen in Vallisneria. Examples: Vallisneria (surface), Zostera (underwater/submarine). |
| Insects | Entomophily | Brightly coloured, fragrant flowers, nectar, sticky/spiny pollen, nectar guides. Examples: rose, sunflower, Salvia. |
| Birds | Ornithophily | Bright red/orange flowers, copious dilute nectar. Examples: Bignonia, Bombax, Erythrina. |
| Bats | Chiropterophily | Large dull-coloured flowers opening at night, fruity smell. Examples: Anthocephalus. |
2.2 Special Pollination Mechanisms
- Cleistogamy: Flowers don't open. Compulsory autogamy. Examples: Oxalis, Viola, Commelina. Ensures seed set even in absence of pollinators. Chasmogamous flowers open normally.
- Outbreeding devices: Mechanisms favouring cross-pollination: (a) Dichogamy: anther/stigma mature at different times (protandry: anthers first; protogyny: stigma first). (b) Herkogamy: physical barrier between anther and stigma. (c) Self-incompatibility: pollen rejected by stigma of same plant (genetic).
3. Pollen-Pistil Interaction and Double Fertilisation
3.1 Pollen Germination
- Pollen lands on compatible stigma → absorbs water → germinates → pollen tube grows through style.
- Generative cell divides → 2 male gametes.
- Pollen tube enters ovule through micropyle (porogamy) — most common. Or through integuments (mesogamy) or chalaza (chalazogamy).
- Pollen tube tip enters embryo sac through synergid → releases 2 male gametes.
3.2 Double Fertilisation (Discovered by Nawaschin, 1898)
Double Fertilisation — unique to angiosperms:
1. Syngamy: One male gamete (n) fuses with egg cell (n) → zygote (2n) → develops into embryo.
2. Triple fusion: Second male gamete (n) fuses with 2 polar nuclei (n + n = 2n central cell, but secondary nucleus = 2n) → primary endosperm nucleus (PEN) (3n) → develops into endosperm.
Total = 2 fertilisation events = Double fertilisation.
1. Syngamy: One male gamete (n) fuses with egg cell (n) → zygote (2n) → develops into embryo.
2. Triple fusion: Second male gamete (n) fuses with 2 polar nuclei (n + n = 2n central cell, but secondary nucleus = 2n) → primary endosperm nucleus (PEN) (3n) → develops into endosperm.
Total = 2 fertilisation events = Double fertilisation.
3.3 Endosperm Development
| Type | Description | Examples |
|---|---|---|
| Nuclear type | PEN divides without cell wall formation first → free nuclei → then cell walls form. Most common in angiosperms. | Coconut water (free nuclear liquid endosperm) + coconut meat (cellular) |
| Cellular type | Cell wall formed after each division of PEN. | Petunia |
| Helobial type | Intermediate between nuclear and cellular. | Monocots |
⚠️ NEET Focus (2014, 2016, 2018, 2020, 2022): Double
fertilisation = feature of angiosperms only. Syngamy → zygote (2n). Triple fusion →
PEN (3n). Endosperm = 3n. Embryo = 2n. Pollen tube enters through micropyle (porogamy).
Nawaschin (1898) discovered double fertilisation. Coconut water = free nuclear endosperm.
4. Post-Fertilisation: Fruit and Seed Development
4.1 Embryo Development
- Zygote develops into embryo after a period of dormancy.
- Proembryo → globular → heart-shaped → torpedo-shaped → mature embryo.
- Dicot embryo: radicle + plumule + 2 cotyledons + hypocotyl + epicotyl.
- Monocot (grass): radicle enclosed in coleorhiza, plumule in coleoptile, 1 cotyledon (scutellum). Endosperm persistent and large (aleurone layer = outermost protein-rich layer).
4.2 Fruit Formation
- Ovary wall → pericarp (fruit wall). Ovule → seed.
- True fruit: develops from ovary only. False fruit (pseudocarp): develops from ovary + other floral parts (e.g., apple = thalamus; cashew = peduncle + true nut).
- Parthenocarpy: fruit development without fertilisation. Seedless fruits. Induced by auxin application. Example: banana.
4.3 Apomixis and Polyembryony
- Apomixis: Seeds form without fertilisation (asexually). No meiosis, no syngamy. Important in agriculture (clonal seeds can be produced). Example: Poa (grass), some Asteraceae, citrus. Types: diplospory (from MMC without meiosis), apospory (somatic cells of nucellus), adventive embryony.
- Polyembryony: Presence of more than one embryo in a seed. Example: citrus (orange, lemon) — multiple nucellar embryos + one sexual embryo.
⚠️ NEET Focus (2015, 2018, 2021): Parthenocarpy = seedless
fruit (banana). Apomixis = seed without fertilisation (e.g., Poa, citrus).
Polyembryony = multiple embryos (citrus). Scutellum = cotyledon in grasses. Aleurone layer
= outermost endosperm layer (protein). Coleorhiza covers radicle;
coleoptile covers plumule in monocots.
🎓 Key NEET Questions
Q1. [NEET 2022] The outermost layer of the anther wall that provides nutrition to
developing pollen grains is:
(a) Epidermis (b) Endothecium (c) Tapetum (d) Middle layers
Answer: (c) Tapetum is the innermost layer of anther wall and is the nutritive layer for developing pollen grains. It is dense cytoplasm, polynucleate, and supplies nutrients and sporopollenin precursors to pollen.
Answer: (c) Tapetum is the innermost layer of anther wall and is the nutritive layer for developing pollen grains. It is dense cytoplasm, polynucleate, and supplies nutrients and sporopollenin precursors to pollen.
Q2. [NEET 2021] The mature embryo sac of a typical angiosperm is:
(a) 7-celled, 8-nucleate (b) 6-celled, 7-nucleate (c) 8-celled, 8-nucleate (d)
7-celled, 7-nucleate
Answer: (a) The mature embryo sac (Polygonum type) is 7-celled and 8-nucleate: egg + 2 synergids (micropylar end) + central cell with 2 polar nuclei + 3 antipodal cells.
Answer: (a) The mature embryo sac (Polygonum type) is 7-celled and 8-nucleate: egg + 2 synergids (micropylar end) + central cell with 2 polar nuclei + 3 antipodal cells.
Q3. [NEET 2020] Triple fusion involves fusion of:
Answer Triple fusion involves one male gamete (n)
fusing with the two polar nuclei (n + n) of the central cell of the embryo sac. The
product is the Primary Endosperm Nucleus (PEN, 3n) which develops into the
endosperm.
Q4. [NEET 2019] Identify the correct statement regarding double fertilisation:
Answer Double fertilisation is unique to angiosperms. It involves
two fusions: (1) Syngamy: male gamete + egg cell → zygote (2n) →
embryo. (2) Triple fusion: male gamete + 2 polar nuclei → PEN (3n) →
endosperm. Discovered by Nawaschin (1898).
Q5. [NEET 2018] Which of the following is the correct sequence of events during
microsporogenesis?
Answer
MMC (pollen mother cell, 2n) → meiosis → tetrad of
microspores (n) → each microspore = pollen grain →
mitosis within pollen grain → vegetative cell + generative cell. Generative
cell divides again (before or after shedding) → 2 male gametes.
Q6. [NEET 2017] Cleistogamous flowers are:
(a) Cross-pollinated (b) Always self-pollinated (c) Pollinated by wind (d)
Pollinated by insects
Answer: (b) Cleistogamous flowers remain closed (never open). They are always self-pollinated (autogamy). This ensures seed set even in adverse conditions (e.g., absence of pollinators). Example: Viola, Oxalis, Commelina. These are produced along with chasmogamous (normally opening) flowers.
Answer: (b) Cleistogamous flowers remain closed (never open). They are always self-pollinated (autogamy). This ensures seed set even in adverse conditions (e.g., absence of pollinators). Example: Viola, Oxalis, Commelina. These are produced along with chasmogamous (normally opening) flowers.
💡 Rapid Revision — Key Points
- Anther = bilobed, 4 microsporangia. Anther wall (outermost inward): Epidermis → Endothecium → Middle layers → Tapetum.
- Pollen wall: outer exine (sporopollenin = most resistant) + inner intine (cellulose).
- Embryo sac = 7-celled, 8-nucleate: egg + 2 synergids + central cell (2 polars) + 3 antipodals.
- Double fertilisation (Nawaschin 1898) = unique to angiosperms. Syngamy→embryo(2n); Triple fusion→endosperm(3n).
- Cleistogamy = closed flowers, always autogamy (Viola, Oxalis).
- Parthenocarpy = seedless fruit (banana). Apomixis = seed without fertilisation (Poa).
- Monocot embryo: scutellum (cotyledon), coleoptile (plumule), coleorhiza (radicle).
CLASS 12 BIOLOGY | NCERT SOLUTIONS
Chapter 2 — Sexual Reproduction in Flowering Plants
All NCERT Exercise Questions with Detailed Solutions
📋 Note: Solutions for all NCERT Class 12 Biology Chapter 2 Exercise questions.
Diagrams described textually as per NCERT.
NCERT Exercise Questions & Solutions
2 MarksQ1. Name the parts of an angiosperm flower in
which development of male and female gametophyte takes place.
✓ Answer
- Male gametophyte (pollen grain / microgametophyte): develops in the microsporangia (pollen sacs) of the anther.
- Female gametophyte (embryo sac / megagametophyte): develops inside the ovule, specifically within the nucellus of the ovule, inside the ovary.
3 MarksQ2. Differentiate between microsporogenesis
and megasporogenesis. Which type of cell division occurs during these events? Name the structures formed
at the end of these two processes.
✓ Answer
Both processes involve meiosis. Subsequent development of gametophytes involves
mitosis.
| Feature | Microsporogenesis | Megasporogenesis |
|---|---|---|
| Site | Microsporangia (anther) | Nucellus of ovule |
| Starting cell | Microspore Mother Cell (MMC, 2n) | Megaspore Mother Cell (MMC, 2n) |
| Division type | Meiosis | Meiosis |
| Product | Tetrad of microspores (pollen grains, n) | 4 megaspores (n); 3 degenerate, 1 functional |
| End structure | Pollen grain (male gametophyte) | Embryo sac (female gametophyte) |
5 MarksQ3. What is meant by monosporic development of
female gametophyte?
✓ Answer
After meiosis of the megaspore mother cell (2n), 4 megaspores (n) are produced. In monosporic development, only one megaspore (usually the one at the chalazal end) remains functional and develops into the female gametophyte (embryo sac); the remaining 3 megaspores degenerate.
Development of embryo sac from functional megaspore (Polygonum type):
After meiosis of the megaspore mother cell (2n), 4 megaspores (n) are produced. In monosporic development, only one megaspore (usually the one at the chalazal end) remains functional and develops into the female gametophyte (embryo sac); the remaining 3 megaspores degenerate.
Development of embryo sac from functional megaspore (Polygonum type):
- Functional megaspore undergoes 3 successive mitotic divisions (free nuclear, no wall formation between nuclei).
- 1 → 2 → 4 → 8 nuclei.
- 8 nuclei organise into 7 cells: 3 at micropylar end (egg apparatus: egg + 2 synergids), 2 polar nuclei in central cell, 3 antipodal cells at chalazal end.
5 MarksQ4. With a neat labelled diagram explain the
seven-celled, eight-nucleate nature of the female gametophyte.
✓ Answer
The mature female gametophyte (embryo sac) is 7-celled and 8-nucleate:
Total = 3 + 1 + 3 = 7 cells. Total nuclei = 3 (egg apparatus) + 2 (polar nuclei in
central cell) + 3 (antipodals) = 8 nuclei.
Hence termed 7-celled, 8-nucleate embryo sac.
The mature female gametophyte (embryo sac) is 7-celled and 8-nucleate:
| Region | Cells / Nuclei | Function |
|---|---|---|
| Micropylar end | Egg cell (1) + 2 Synergids = egg apparatus (3 cells). Synergids have filiform apparatus. | Egg = female gamete. Synergids guide pollen tube entry and release. |
| Centre | Central cell (1 cell) with 2 polar nuclei. Polars may fuse = secondary nucleus (2n). | Participates in triple fusion → endosperm (3n). |
| Chalazal end | 3 antipodal cells. | Nutritive; degenerate after fertilisation. |
Hence termed 7-celled, 8-nucleate embryo sac.
5 MarksQ5. What is double fertilisation? Explain its
significance in angiosperms.
✓ Answer
Double Fertilisation (discovered by Nawaschin, 1898): Two fertilisation events occurring simultaneously in angiosperms:
Double Fertilisation (discovered by Nawaschin, 1898): Two fertilisation events occurring simultaneously in angiosperms:
- Syngamy: One male gamete (n) fuses with the egg cell (n) → zygote (2n) → develops into embryo.
- Triple fusion: Second male gamete (n) fuses with the two polar nuclei (2n total in central cell) → Primary Endosperm Nucleus (PEN) (3n) → develops into endosperm.
- Ensures development of endosperm only when fertilisation occurs — prevents wastage of resources.
- Endosperm (3n) provides nutrition to the developing embryo.
- Unique feature of angiosperms — explains their evolutionary success.
- The triploid endosperm is a new genetic combination of father (n) + 2× mother (n+n).
3 MarksQ6. Describe the various types of pollination.
What is the difference between geitonogamy and xenogamy?
✓ Answer
Types of Pollination:
Types of Pollination:
- Autogamy: Pollen transferred from anther to stigma of the same flower. Requires synchrony of pollen maturation and stigma receptivity. Example: cleistogamous flowers (Viola, Oxalis).
- Geitonogamy: Pollen transferred from anther of one flower to stigma of another flower on the SAME plant. Functionally cross-pollination (mediated by pollinator) but genetically similar to self-pollination (same plant genome).
- Xenogamy (Allogamy): Pollen transferred from anther of one plant to stigma of a different plant of same species. Genetically true cross-pollination. Introduces genetic variation.
| Feature | Geitonogamy | Xenogamy |
|---|---|---|
| Pollen source | Different flower of SAME plant | Flower of DIFFERENT plant |
| Genetic effect | Genetically like self-pollination | Genetic variation introduced |
| Requires pollinator? | Usually yes | Yes |
3 MarksQ7. What is apomixis and what is its
importance?
✓ Answer
Apomixis: A form of asexual reproduction in plants that mimics sexual reproduction — seeds are formed WITHOUT fertilisation (no meiosis, no syngamy). The embryo develops from vegetative (somatic) cells of the ovule or from unreduced megaspore (without meiosis).
Types:
Apomixis: A form of asexual reproduction in plants that mimics sexual reproduction — seeds are formed WITHOUT fertilisation (no meiosis, no syngamy). The embryo develops from vegetative (somatic) cells of the ovule or from unreduced megaspore (without meiosis).
Types:
- Diplospory: MMC divides mitotically (no meiosis) → unreduced diploid embryo sac.
- Apospory: Embryo sac develops from somatic cells of nucellus (nucellar embryony).
- Adventive embryony: Embryos from cells of nucellus or integuments directly (e.g., Citrus, mango).
- Produces clonal seeds — offspring identical to parent (no variation).
- Important in agriculture: can fix hybrid vigour (heterosis) permanently over successive generations without costly hybrid seed production each year.
- Seeds produced even without pollination.
- Citrus polyembryony: nucellar embryos are uniform and disease free.
✍ NCERT Exercise — Score Guide
Q1: 2 marks | Q2: 3 marks | Q3: 5 marks | Q4: 5 marks | Q5: 5 marks | Q6: 3 marks | Q7: 3 marks
Q1: 2 marks | Q2: 3 marks | Q3: 5 marks | Q4: 5 marks | Q5: 5 marks | Q6: 3 marks | Q7: 3 marks
CLASS 12 BIOLOGY | NEET RAPID CAPSULE
Facts & High-Yield Points
Chapter 2 — Sexual Reproduction in Flowering Plants | 22 Key Facts for NEET
🍊 Anther & Pollen
FACT #01 — Anther Wall Layers
Outside to inside: Epidermis → Endothecium → Middle layers → Tapetum.
Tapetum = nutritive (innermost), dense cytoplasm, polynucleate. Provides sporopollenin
precursors, nutrients to pollen. Anther = bilobed = 4 microsporangia.FACT #02 — Pollen Wall
Exine (outer): sporopollenin — most resistant biological
material (survives strong acid, alkali, heat, decay). Responsible for pollen fossil record and
allergies. Intine (inner): cellulose + pectin. Germ pore = aperture.FACT #03 — Pollen Structure
Mature pollen = 2-celled: large vegetative (tube) cell + small
generative cell (inside). Generative cell divides → 2 male
gametes. Some species shed 3-celled pollen (generative divides before shedding).FACT #04 — Embryo Sac (7+8)
7-celled, 8-nucleate: Egg + 2 synergids (micropylar, filiform apparatus) + central cell
with 2 polar nuclei + 3 antipodals (chalazal, nutritive, degenerate).
Monosporic development = 1 functional megaspore (chalazal end).
🌻 Pollination
FACT #05 — Types of Pollination
Autogamy: same flower. Geitonogamy: different flower, same plant
(genetically = self-pollination). Xenogamy: different plant, same species (genetic
variation). Cleistogamy: closed flowers, compulsory autogamy (Viola, Oxalis,
Commelina).FACT #06 — Pollination Agents
Wind = Anemophily (maize, grasses; feathery stigma, light pollen). Water =
Hydrophily (Vallisneria surface; Zostera submarine). Insect =
Entomophily (fragrant, coloured flowers). Bird = Ornithophily (red
flowers, dilute nectar).FACT #07 — Outbreeding Devices
Dichogamy: anther & stigma mature at different times (Protandry = stamens first;
Protogyny = stigma first). Self-incompatibility: pollen rejected by own stigma (genetic
S-locus). Unisexuality: monoecious or dioecious plants.
🌿 Fertilisation
FACT #08 — Double Fertilisation
Unique to angiosperms. Discovered by Nawaschin (1898). (1)
Syngamy: male gamete (n) + egg (n) → Zygote (2n) → embryo.
(2) Triple fusion: male gamete (n) + 2 polar nuclei (2n) → PEN
(3n) → endosperm.FACT #09 — Pollen Tube Entry
Porogamy: pollen tube enters through micropyle (most common).
Mesogamy: through integuments. Chalazogamy: through chalaza. Pollen
tube enters synergid → releases 2 male gametes in embryo sac.FACT #10 — Endosperm Ploidy
Endosperm = 3n (triploid). Develops from PEN. Coconut water = free
nuclear (liquid) endosperm (nuclear type). Coconut meat = cellular endosperm. Aleurone
layer = outermost protein-rich layer of endosperm in cereals.
🍏 Post-Fertilisation
FACT #11 — Fruit Types
True fruit: from ovary only (mango, tomato). False fruit (pseudocarp):
from ovary + other floral parts. Apple = thalamus; Cashew = peduncle. Parthenocarpy:
seedless fruit without fertilisation (banana). Induced by auxin.FACT #12 — Apomixis & Polyembryony
Apomixis: seed without fertilisation. Seeds are clonal. Examples: Poa, citrus,
dandelion. Agriculture: fixes hybrid vigour. Polyembryony: multiple embryos per seed
(citrus — nucellar + sexual embryos).FACT #13 — Monocot Embryo
Grass embryo: scutellum (single cotyledon), coleoptile (covers
plumule), coleorhiza (covers radicle). Aleurone layer present. Endosperm persistent and
large in monocots.🧠 Mnemonics — Remember Fast
Anther Wall: “Every Engineer Makes Telephone”
Epidermis → Endothecium → Middle layers
→ Tapetum. (outside → inside). Tapetum = nutritive, innermost.
Embryo sac: “3-1-3 = 7 cells, 8 nuclei”
3 (egg apparatus: egg+2 synergids) + 1 central cell (2 polar nuclei) +
3 antipodals = 7 cells, but central cell has 2 nuclei = 3+2+3 = 8
nuclei.
Double Fertilisation: “S+T”
Syngamy = egg + male gamete → zygote (2n) → embryo. Triple
fusion = polars (2) + male gamete → PEN (3n) → endosperm. Nawaschin 1898. Unique to
angiosperms.
Pollination: “A-G-X”
Autogamy = same flower. Geitonogamy = same plant (genetically like
auto). Xenogamy = different plant (true cross). Cleistogamy = always
autogamy (closed flowers).
🔢 Critical Numbers — Never Forget
4 — microsporangia per anther
7-celled, 8-nucleate — mature embryo sac
2n — zygote (syngamy)
3n — PEN (triple fusion, endosperm)
1898 — Nawaschin (double fertilisation)
Sporopollenin — most resistant matter
Banana — parthenocarpic fruit
Chalazal — functional megaspore position
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📱 Practice MCQs for this topic inside our App
📱 Practice MCQs for this topic inside our App
📱 Practice MCQs for this topic inside our App