The Mango You Eat Is a Swollen Ovary With a Seed Inside
Learn how meiosis creates variation, the parts of a flower and their functions, how self-pollination differs from cross-pollination, and how an ovule becomes a seed and an ovary a fruit.
What part of the plant are you eating when you eat a mango?
The ovary of a flower, swollen with stored food — and the stone inside it is the ovule, now a seed.
Every fruit began as the ovary at the base of a flower's pistil. Once fertilisation has happened inside it, the ovary grows and its wall thickens into the flesh you eat, while each ovule inside becomes a seed containing an embryo.
The other parts of the flower simply fall away. The petals wither, the sepals drop, the stamens dry up, and the style and stigma shrivel — which is why the tip of many fruits carries a small dry scar where the style used to be.
So a mango, a pea pod, a tomato and a grain of wheat are all the same structure at different scales: a fertilised ovary. This page covers the second part of the CBSE Class 9 Science chapter on reproduction, and it traces that journey from flower to fruit.
Every fruit began as the ovary at the base of a flower's pistil. Once fertilisation has happened inside it, the ovary grows and its wall thickens into the flesh you eat, while each ovule inside becomes a seed containing an embryo.
The other parts of the flower simply fall away. The petals wither, the sepals drop, the stamens dry up, and the style and stigma shrivel — which is why the tip of many fruits carries a small dry scar where the style used to be.
So a mango, a pea pod, a tomato and a grain of wheat are all the same structure at different scales: a fertilised ovary. This page covers the second part of the CBSE Class 9 Science chapter on reproduction, and it traces that journey from flower to fruit.
How does meiosis create variation in sexual reproduction?
In two steps — by shuffling the chromosomes as gametes are made, and by combining gametes from two different parents.
Step one: meiosis shuffles. Gametes are produced by meiosis, which halves the chromosome number so that each gamete receives one chromosome from each pair. Which member of each pair a given gamete receives is a matter of chance, so an enormous number of different gamete types can be produced from a single parent.
Step two: fertilisation combines. A gamete from one parent fuses with a gamete from another parent. The offspring therefore carries a combination of chromosomes that existed in neither parent before.
Why that matters. The offspring of sexual reproduction differ from each other and from both parents. As the previous part of this chapter showed, asexual offspring are clones and differ from the parent only by rare copying errors. Sexual reproduction generates variation by design, every generation.
Everyday evidence. Brothers and sisters share the same two parents and are noticeably different from one another in height, features and build. Seeds from a single mango tree, planted and grown, produce trees whose fruit differs — which is exactly why valuable mango varieties are propagated by grafting rather than from seed, as the previous part of this chapter explained.
Variation comes from the process, not from mistakes. A student meeting this for the first time often assumes variation must be a kind of error. It is the intended outcome of meiosis followed by fertilisation, and it is the reason sexual reproduction is worth its greater cost.
The chromosome number is restored by fertilisation. Meiosis halves it and fusion doubles it back, so the offspring has the same number as each parent. Without the halving, every generation would carry twice as many chromosomes as the last — which is why meiosis and fertilisation must work as a pair, as the cell chapter of this course established with the human counts of and .
Step one: meiosis shuffles. Gametes are produced by meiosis, which halves the chromosome number so that each gamete receives one chromosome from each pair. Which member of each pair a given gamete receives is a matter of chance, so an enormous number of different gamete types can be produced from a single parent.
Step two: fertilisation combines. A gamete from one parent fuses with a gamete from another parent. The offspring therefore carries a combination of chromosomes that existed in neither parent before.
Why that matters. The offspring of sexual reproduction differ from each other and from both parents. As the previous part of this chapter showed, asexual offspring are clones and differ from the parent only by rare copying errors. Sexual reproduction generates variation by design, every generation.
Everyday evidence. Brothers and sisters share the same two parents and are noticeably different from one another in height, features and build. Seeds from a single mango tree, planted and grown, produce trees whose fruit differs — which is exactly why valuable mango varieties are propagated by grafting rather than from seed, as the previous part of this chapter explained.
Variation comes from the process, not from mistakes. A student meeting this for the first time often assumes variation must be a kind of error. It is the intended outcome of meiosis followed by fertilisation, and it is the reason sexual reproduction is worth its greater cost.
The chromosome number is restored by fertilisation. Meiosis halves it and fusion doubles it back, so the offspring has the same number as each parent. Without the halving, every generation would carry twice as many chromosomes as the last — which is why meiosis and fertilisation must work as a pair, as the cell chapter of this course established with the human counts of and .
What are the parts of a flower and what does each do?
Four sets of parts, arranged in rings from the outside in, and the inner two are the reproductive ones.
Sepals — the outermost ring, together called the calyx. Usually green and leaf-like, they protect the flower while it is still a bud.
Petals — the next ring, together called the corolla. Often brightly coloured and scented, they attract pollinators.
Stamen — the male reproductive part, and all the stamens together are the androecium. Each stamen has two parts:
- The filament, a slender stalk
- The anther, a swollen head that produces pollen grains, each containing the male gamete
Pistil or carpel — the female reproductive part, and all together the gynoecium. It has three parts:
- The stigma at the top, often sticky, which receives pollen
- The style, the stalk connecting stigma to ovary
- The ovary at the base, containing one or more ovules, each holding the female gamete or egg
Bisexual and unisexual flowers. A bisexual flower has both stamens and pistil — Hibiscus, mustard, rose. A unisexual flower has only one of the two — papaya, watermelon, maize — so a plant may bear separate male and female flowers, or the two sexes may be on separate plants.
Everyday evidence. A Hibiscus flower is the standard specimen because all four sets are large and easy to separate. Its stamens form a tube around the long style, and the five-lobed stigma stands out beyond them. Dust the anthers with a finger and the yellow pollen comes away visibly.
The stigma receives pollen and the anther produces it — and swapping those two words is the commonest error in labelling a flower diagram. The anther is at the top of a stamen; the stigma is at the top of the pistil. One is male and one is female, and both sit high in the flower where they are easy to confuse in a hurry.
Only a bisexual flower can self-pollinate. A unisexual flower has no anthers and pistil in the same flower, so its pollen must travel to a different flower — which means the flower's own structure has already decided part of the question the next section asks.
Sepals — the outermost ring, together called the calyx. Usually green and leaf-like, they protect the flower while it is still a bud.
Petals — the next ring, together called the corolla. Often brightly coloured and scented, they attract pollinators.
Stamen — the male reproductive part, and all the stamens together are the androecium. Each stamen has two parts:
- The filament, a slender stalk
- The anther, a swollen head that produces pollen grains, each containing the male gamete
Pistil or carpel — the female reproductive part, and all together the gynoecium. It has three parts:
- The stigma at the top, often sticky, which receives pollen
- The style, the stalk connecting stigma to ovary
- The ovary at the base, containing one or more ovules, each holding the female gamete or egg
Bisexual and unisexual flowers. A bisexual flower has both stamens and pistil — Hibiscus, mustard, rose. A unisexual flower has only one of the two — papaya, watermelon, maize — so a plant may bear separate male and female flowers, or the two sexes may be on separate plants.
Everyday evidence. A Hibiscus flower is the standard specimen because all four sets are large and easy to separate. Its stamens form a tube around the long style, and the five-lobed stigma stands out beyond them. Dust the anthers with a finger and the yellow pollen comes away visibly.
The stigma receives pollen and the anther produces it — and swapping those two words is the commonest error in labelling a flower diagram. The anther is at the top of a stamen; the stigma is at the top of the pistil. One is male and one is female, and both sit high in the flower where they are easy to confuse in a hurry.
Only a bisexual flower can self-pollinate. A unisexual flower has no anthers and pistil in the same flower, so its pollen must travel to a different flower — which means the flower's own structure has already decided part of the question the next section asks.
How does self-pollination differ from cross-pollination?
Pollination is the transfer of pollen from an anther to a stigma, and it is self or cross depending on whether the two belong to the same plant.
Self-pollination: pollen reaches the stigma of the same flower, or of another flower on the same plant. It is possible only in bisexual flowers.
Cross-pollination: pollen is carried to a flower on a different plant of the same species. It requires an external agent to carry the pollen.
The agents of cross-pollination, with the flower features that suit each.
Wind. Pollen is light, dry and powdery, produced in very large quantities, and the stigmas are often large and feathery to catch it. The flowers themselves are small, dull and usually without scent or nectar — there is nothing to attract, so nothing is spent on attraction.
- Examples: grasses, maize, wheat
Water. Used by aquatic plants, where pollen is carried on or under the water surface.
- Examples: Vallisneria, Hydrilla
Insects and other animals. Flowers are brightly coloured, often scented, and produce nectar as a reward. Their pollen is sticky or spiny so that it clings to a visiting body.
- Insects: bees, butterflies, moths
- Also birds such as the sunbird, and bats
Everyday evidence. A field of maize releases clouds of pollen that settle as a fine dust on everything nearby — that is wind pollination, and the sheer waste of pollen is the price of relying on chance. A Hibiscus or a sunflower, by contrast, spends its resources on colour, scent and nectar and gets its pollen carried deliberately.
You can usually predict the agent from the flower. Large, coloured, scented, nectar-producing and sticky-pollened means animal. Small, dull, scentless, with light dry pollen in huge amounts and feathery stigmas, means wind. The structure is an adaptation to the method, and a question describing a flower is giving you the answer.
Cross-pollination produces more variation than self-pollination. In self-pollination both gametes come from the same plant, so the offspring resemble the parent closely. In cross-pollination the two parents differ, so the combinations are new — which links directly to the variation argument of the first section. Self-pollination preserves the type; cross-pollination creates variety, and many plants have structural features that actively prevent self-pollination for exactly that reason.
Self-pollination: pollen reaches the stigma of the same flower, or of another flower on the same plant. It is possible only in bisexual flowers.
Cross-pollination: pollen is carried to a flower on a different plant of the same species. It requires an external agent to carry the pollen.
The agents of cross-pollination, with the flower features that suit each.
Wind. Pollen is light, dry and powdery, produced in very large quantities, and the stigmas are often large and feathery to catch it. The flowers themselves are small, dull and usually without scent or nectar — there is nothing to attract, so nothing is spent on attraction.
- Examples: grasses, maize, wheat
Water. Used by aquatic plants, where pollen is carried on or under the water surface.
- Examples: Vallisneria, Hydrilla
Insects and other animals. Flowers are brightly coloured, often scented, and produce nectar as a reward. Their pollen is sticky or spiny so that it clings to a visiting body.
- Insects: bees, butterflies, moths
- Also birds such as the sunbird, and bats
Everyday evidence. A field of maize releases clouds of pollen that settle as a fine dust on everything nearby — that is wind pollination, and the sheer waste of pollen is the price of relying on chance. A Hibiscus or a sunflower, by contrast, spends its resources on colour, scent and nectar and gets its pollen carried deliberately.
You can usually predict the agent from the flower. Large, coloured, scented, nectar-producing and sticky-pollened means animal. Small, dull, scentless, with light dry pollen in huge amounts and feathery stigmas, means wind. The structure is an adaptation to the method, and a question describing a flower is giving you the answer.
Cross-pollination produces more variation than self-pollination. In self-pollination both gametes come from the same plant, so the offspring resemble the parent closely. In cross-pollination the two parents differ, so the combinations are new — which links directly to the variation argument of the first section. Self-pollination preserves the type; cross-pollination creates variety, and many plants have structural features that actively prevent self-pollination for exactly that reason.
How does fertilisation turn an ovule into a seed?
The pollen grows a tube down to the ovule, the gametes fuse inside it, and the surrounding structures then swell into seed and fruit.
The sequence, in order:
- A pollen grain lands on the stigma — this is pollination
- The pollen grain germinates and grows a pollen tube down through the style
- The tube reaches the ovary and enters an ovule
- The male gamete travels down the tube and fuses with the egg inside the ovule — this is fertilisation
- The product of that fusion is the zygote
What each part becomes afterwards:
- The zygote divides repeatedly to form the embryo
- The ovule becomes the seed, with the embryo inside and a protective seed coat
- The ovary becomes the fruit, its wall thickening into the flesh
- The petals, sepals, stamens, style and stigma wither and usually fall away
Everyday evidence. A pea pod is one ovary that contained several ovules, so it becomes one fruit holding several seeds. A mango ovary held a single ovule, so it becomes one fruit with one stone. Look at the end of a tomato or a brinjal and the small dry mark is where the style once stood.
Pollination and fertilisation are not the same event. This is the most examined distinction in the section, so it is worth stating precisely:
- Pollination is the transfer of pollen to a stigma. It happens outside the ovary, it needs an agent, and it may well fail
- Fertilisation is the fusion of gametes. It happens inside the ovule, and it needs a pollen tube to have reached there first
Every fertilisation requires a prior pollination. But pollination does not guarantee fertilisation — pollen may land on the stigma of the wrong species, or fail to germinate, or the tube may not reach an ovule. So the two words describe two separate steps, and using one where the other is meant loses the mark even when the biology described is otherwise right.
The number of seeds is set by the number of ovules. A fruit with many seeds grew from an ovary with many ovules, each of which had to be fertilised separately by its own pollen tube. That is why a partly pollinated flower can produce a lopsided or half-empty fruit — some ovules were fertilised and some were not.
The sequence, in order:
- A pollen grain lands on the stigma — this is pollination
- The pollen grain germinates and grows a pollen tube down through the style
- The tube reaches the ovary and enters an ovule
- The male gamete travels down the tube and fuses with the egg inside the ovule — this is fertilisation
- The product of that fusion is the zygote
What each part becomes afterwards:
- The zygote divides repeatedly to form the embryo
- The ovule becomes the seed, with the embryo inside and a protective seed coat
- The ovary becomes the fruit, its wall thickening into the flesh
- The petals, sepals, stamens, style and stigma wither and usually fall away
Everyday evidence. A pea pod is one ovary that contained several ovules, so it becomes one fruit holding several seeds. A mango ovary held a single ovule, so it becomes one fruit with one stone. Look at the end of a tomato or a brinjal and the small dry mark is where the style once stood.
Pollination and fertilisation are not the same event. This is the most examined distinction in the section, so it is worth stating precisely:
- Pollination is the transfer of pollen to a stigma. It happens outside the ovary, it needs an agent, and it may well fail
- Fertilisation is the fusion of gametes. It happens inside the ovule, and it needs a pollen tube to have reached there first
Every fertilisation requires a prior pollination. But pollination does not guarantee fertilisation — pollen may land on the stigma of the wrong species, or fail to germinate, or the tube may not reach an ovule. So the two words describe two separate steps, and using one where the other is meant loses the mark even when the biology described is otherwise right.
The number of seeds is set by the number of ovules. A fruit with many seeds grew from an ovary with many ovules, each of which had to be fertilised separately by its own pollen tube. That is why a partly pollinated flower can produce a lopsided or half-empty fruit — some ovules were fertilised and some were not.
Exam tip
Exam tip: label the diagram and keep pollination apart from fertilisation
Learn the flower diagram with all four sets: sepals (calyx), petals (corolla), stamens (androecium) and pistil (gynoecium).
Anther produces pollen; stigma receives it. The anther is on the stamen (male), the stigma on the pistil (female). Swapping them is the standard labelling error.
Name the sub-parts: stamen is filament plus anther; pistil is stigma, style and ovary, with ovules inside.
Pollination is transfer of pollen; fertilisation is fusion of gametes. Pollination happens outside and may fail; fertilisation happens inside the ovule. Never use one word for the other.
Give the sequence in order: pollination, germination of the pollen grain, pollen tube down the style, fusion, zygote.
Learn what becomes what: zygote to embryo, ovule to seed, ovary to fruit, and the rest withers.
Only bisexual flowers can self-pollinate.
Match the agent to the flower: wind means light dry pollen in quantity with feathery stigmas and dull flowers; insect means colour, scent, nectar and sticky pollen; water means aquatic plants such as Vallisneria.
Cross-pollination gives more variation than self-pollination.
And for the variation question, give both steps: meiosis shuffles the chromosomes and fertilisation combines two different parents.
Anther produces pollen; stigma receives it. The anther is on the stamen (male), the stigma on the pistil (female). Swapping them is the standard labelling error.
Name the sub-parts: stamen is filament plus anther; pistil is stigma, style and ovary, with ovules inside.
Pollination is transfer of pollen; fertilisation is fusion of gametes. Pollination happens outside and may fail; fertilisation happens inside the ovule. Never use one word for the other.
Give the sequence in order: pollination, germination of the pollen grain, pollen tube down the style, fusion, zygote.
Learn what becomes what: zygote to embryo, ovule to seed, ovary to fruit, and the rest withers.
Only bisexual flowers can self-pollinate.
Match the agent to the flower: wind means light dry pollen in quantity with feathery stigmas and dull flowers; insect means colour, scent, nectar and sticky pollen; water means aquatic plants such as Vallisneria.
Cross-pollination gives more variation than self-pollination.
And for the variation question, give both steps: meiosis shuffles the chromosomes and fertilisation combines two different parents.
Did you know
Why wind-pollinated flowers are never beautiful
Think of the flowers people grow for their looks — rose, jasmine, Hibiscus, marigold, sunflower. Every one is animal-pollinated. Now think of the flowers of wheat, rice, maize and grass, and most people cannot picture them at all.
That is not a coincidence. Colour, scent and nectar are advertising, and they are expensive to produce. A plant only makes them if there is an animal to advertise to.
Wind has no eyes and cannot be bribed. So a wind-pollinated plant spends nothing on petals, nothing on perfume and nothing on nectar, and puts everything into quantity of pollen instead — because the method works purely by chance, and the only way to improve the odds is to release far more pollen than can possibly be needed. The stigmas grow large and feathery for the same reason: a bigger net catches more of what is drifting past.
The two strategies show a clear trade-off. Animal pollination is efficient — pollen is carried directly from one flower to another of the same species — and it costs a great deal in petals, scent and nectar. Wind pollination is wasteful but cheap, and it needs no partner to be present at all.
There is a consequence people notice every year. The clouds of pollen released by wind-pollinated plants are what cause seasonal allergies, and the showy flowers in a garden rarely do, because their pollen is sticky and stays on the insect rather than drifting into the air.
So the appearance of a flower is a record of how it gets pollinated. A plant that has evolved to be visited is built to be noticed, and a plant that relies on the wind has no reason to be looked at.
That is not a coincidence. Colour, scent and nectar are advertising, and they are expensive to produce. A plant only makes them if there is an animal to advertise to.
Wind has no eyes and cannot be bribed. So a wind-pollinated plant spends nothing on petals, nothing on perfume and nothing on nectar, and puts everything into quantity of pollen instead — because the method works purely by chance, and the only way to improve the odds is to release far more pollen than can possibly be needed. The stigmas grow large and feathery for the same reason: a bigger net catches more of what is drifting past.
The two strategies show a clear trade-off. Animal pollination is efficient — pollen is carried directly from one flower to another of the same species — and it costs a great deal in petals, scent and nectar. Wind pollination is wasteful but cheap, and it needs no partner to be present at all.
There is a consequence people notice every year. The clouds of pollen released by wind-pollinated plants are what cause seasonal allergies, and the showy flowers in a garden rarely do, because their pollen is sticky and stays on the insect rather than drifting into the air.
So the appearance of a flower is a record of how it gets pollinated. A plant that has evolved to be visited is built to be noticed, and a plant that relies on the wind has no reason to be looked at.
Exam relevance
How does plant reproduction in Class 9 feed into NEET?
This page is the foundation for the Class 12 Biology chapter Sexual Reproduction in Flowering Plants, a standing part of the NEET syllabus, and it is one of the chapters NEET draws on most heavily.
That chapter develops every item on this page. The anther is treated in detail down to its four microsporangia and its layers; the ovule is described with its integuments, micropyle, nucellus and embryo sac; and the pollen grain's journey is followed as pollen-pistil interaction. The Class 9 sequence — pollination, germination, pollen tube, fusion — is the skeleton that detail hangs on.
The biggest addition is double fertilisation. In Class 12 you learn that two male gametes travel down each pollen tube: one fuses with the egg to give the zygote, and the other fuses with two polar nuclei to give the primary endosperm nucleus, which becomes the food-storing endosperm of the seed. That is why the Class 9 statement the male gamete fuses with the egg is completed rather than corrected later, and a student who has the simple version firmly in place finds the double version straightforward.
Pollination becomes a chapter section of its own, with agents classified formally and with the outbreeding devices by which plants prevent self-pollination — the very features the previous section mentioned. NEET asks about those devices directly.
The meiosis-and-variation argument feeds into Class 12 Principles of Inheritance and Variation and Evolution, where variation becomes the raw material of natural selection.
What the questions look like. Diagram-based questions dominate for this material in NEET — a labelled flower, anther or ovule with one part to identify. Match-the-column items pair a floral part with its function, or a plant with its pollination agent, and the pairs that catch students out are Vallisneria (water) and maize (wind). Assertion-reason questions favour the statement that cross-pollination produces more variation. Statement-count questions ask how many of several listed structures develop into a named part of the seed or fruit.
How board and competitive emphasis differ. A board paper asks you to draw and label a flower, describe fertilisation in sequence, and give two differences between self and cross-pollination. A NEET item gives a structure and asks what it becomes, or gives a set of statements about the post-fertilisation changes and asks which are correct — so the what-becomes-what list matters more than the description of the process.
The single trap that costs the most marks. Using pollination and fertilisation interchangeably. Pollination is the transfer of pollen, outside the ovary; fertilisation is the fusion of gametes, inside the ovule. Questions are written specifically to separate them, and an answer that describes fusion when asked about pollination scores nothing however accurate the biology.
A second trap worth naming. Confusing anther with stigma on a diagram. Both sit high in the flower and both are the business end of their structure, but one makes pollen and the other receives it. Fix them by their stalks: filament and anther are male; style and stigma are female.
That chapter develops every item on this page. The anther is treated in detail down to its four microsporangia and its layers; the ovule is described with its integuments, micropyle, nucellus and embryo sac; and the pollen grain's journey is followed as pollen-pistil interaction. The Class 9 sequence — pollination, germination, pollen tube, fusion — is the skeleton that detail hangs on.
The biggest addition is double fertilisation. In Class 12 you learn that two male gametes travel down each pollen tube: one fuses with the egg to give the zygote, and the other fuses with two polar nuclei to give the primary endosperm nucleus, which becomes the food-storing endosperm of the seed. That is why the Class 9 statement the male gamete fuses with the egg is completed rather than corrected later, and a student who has the simple version firmly in place finds the double version straightforward.
Pollination becomes a chapter section of its own, with agents classified formally and with the outbreeding devices by which plants prevent self-pollination — the very features the previous section mentioned. NEET asks about those devices directly.
The meiosis-and-variation argument feeds into Class 12 Principles of Inheritance and Variation and Evolution, where variation becomes the raw material of natural selection.
What the questions look like. Diagram-based questions dominate for this material in NEET — a labelled flower, anther or ovule with one part to identify. Match-the-column items pair a floral part with its function, or a plant with its pollination agent, and the pairs that catch students out are Vallisneria (water) and maize (wind). Assertion-reason questions favour the statement that cross-pollination produces more variation. Statement-count questions ask how many of several listed structures develop into a named part of the seed or fruit.
How board and competitive emphasis differ. A board paper asks you to draw and label a flower, describe fertilisation in sequence, and give two differences between self and cross-pollination. A NEET item gives a structure and asks what it becomes, or gives a set of statements about the post-fertilisation changes and asks which are correct — so the what-becomes-what list matters more than the description of the process.
The single trap that costs the most marks. Using pollination and fertilisation interchangeably. Pollination is the transfer of pollen, outside the ovary; fertilisation is the fusion of gametes, inside the ovule. Questions are written specifically to separate them, and an answer that describes fusion when asked about pollination scores nothing however accurate the biology.
A second trap worth naming. Confusing anther with stigma on a diagram. Both sit high in the flower and both are the business end of their structure, but one makes pollen and the other receives it. Fix them by their stalks: filament and anther are male; style and stigma are female.
Key takeaways
Flowers, pollination and fertilisation: quick revision
- Variation arises in two steps: meiosis shuffles the chromosomes as gametes form, and fertilisation combines gametes from two different parents.
- Meiosis halves the chromosome number and fertilisation restores it, which is why the two must work as a pair.
- Flower parts, outside in: sepals (calyx) protect the bud; petals (corolla) attract pollinators; stamens (androecium) are male; pistil (gynoecium) is female.
- Stamen filament anther, and the anther makes pollen grains with the male gamete.
- Pistil stigma style ovary, and the ovary holds ovules, each with the egg.
- Anther produces pollen; stigma receives it. Hibiscus is the standard specimen.
- Bisexual flowers have both parts (Hibiscus, mustard); unisexual flowers have one (papaya, maize).
- Pollination is the transfer of pollen from anther to stigma. Self-pollination is within the same flower or plant and needs a bisexual flower; cross-pollination is between different plants of the same species.
- Wind: light, dry, abundant pollen, feathery stigmas, small dull flowers — grasses, maize, wheat.
- Water: aquatic plants — Vallisneria, Hydrilla.
- Insects and animals: bright colour, scent, nectar, sticky or spiny pollen — bees, butterflies, sunbirds, bats.
- You can predict the agent from the flower's structure.
- Cross-pollination gives more variation; self-pollination preserves the parental type.
- Fertilisation sequence: pollen lands on the stigma, germinates, grows a pollen tube through the style into an ovule, and the male gamete fuses with the egg to give the zygote.
- Afterwards: zygote to embryo, ovule to seed, ovary to fruit, and petals, sepals, stamens, style and stigma wither.
- A pea pod is one ovary with several ovules, so one fruit with several seeds; a mango had one ovule, so one seed.
- Pollination is not fertilisation. Pollination is transfer, outside, and may fail; fertilisation is fusion, inside the ovule.
Draw a flower from memory, label every part, then write beside each reproductive structure what it becomes after fertilisation — that second column is what most questions actually ask for.
- Meiosis halves the chromosome number and fertilisation restores it, which is why the two must work as a pair.
- Flower parts, outside in: sepals (calyx) protect the bud; petals (corolla) attract pollinators; stamens (androecium) are male; pistil (gynoecium) is female.
- Stamen filament anther, and the anther makes pollen grains with the male gamete.
- Pistil stigma style ovary, and the ovary holds ovules, each with the egg.
- Anther produces pollen; stigma receives it. Hibiscus is the standard specimen.
- Bisexual flowers have both parts (Hibiscus, mustard); unisexual flowers have one (papaya, maize).
- Pollination is the transfer of pollen from anther to stigma. Self-pollination is within the same flower or plant and needs a bisexual flower; cross-pollination is between different plants of the same species.
- Wind: light, dry, abundant pollen, feathery stigmas, small dull flowers — grasses, maize, wheat.
- Water: aquatic plants — Vallisneria, Hydrilla.
- Insects and animals: bright colour, scent, nectar, sticky or spiny pollen — bees, butterflies, sunbirds, bats.
- You can predict the agent from the flower's structure.
- Cross-pollination gives more variation; self-pollination preserves the parental type.
- Fertilisation sequence: pollen lands on the stigma, germinates, grows a pollen tube through the style into an ovule, and the male gamete fuses with the egg to give the zygote.
- Afterwards: zygote to embryo, ovule to seed, ovary to fruit, and petals, sepals, stamens, style and stigma wither.
- A pea pod is one ovary with several ovules, so one fruit with several seeds; a mango had one ovule, so one seed.
- Pollination is not fertilisation. Pollination is transfer, outside, and may fail; fertilisation is fusion, inside the ovule.
Draw a flower from memory, label every part, then write beside each reproductive structure what it becomes after fertilisation — that second column is what most questions actually ask for.