Fertilisation and germination
Introduced| English | Meaning |
|---|---|
| seed/siːd/ | A plant structure containing an embryo and a food supply protected by a seed coat. |
| pollen tube/ˈpɒlən tjuːb/ | The tube grown by a pollen grain down the style to deliver the male gamete. |
| ovule/ˈɒvjuːl/ | ovule |
| fruit/fruːt/ | fruit |
| germination/ˌdʒɜːmɪˈneɪʃn/ | The resumption of growth of a seed embryo, developing into a seedling under suitable conditions. |
From pollen to a new plant
- After pollination, the plant must complete fertilisation and grow a seed 种子 — which later sprouts.
- These steps turn a flower into the next generation.
After landing on the stigma, a pollen grain grows a:
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The pollen tube carries the male nucleus to the ovule.
After fertilisation, the ovule becomes a:
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The ovule becomes a seed; the ovary becomes a fruit.
Fertilisation in plants
- A pollen grain grows a pollen tube 花粉管 down the style to an ovule 胚珠 in the ovary.
- The male nucleus fuses with the ovule — fertilisation. The ovule becomes a seed; the ovary becomes a fruit 果实.
Pollination transfers pollen from anther to stigma — the first step toward a new plant
Germination of a seed
A seed stays dormant until it has the right conditions, then the young plant grows out.
Which conditions does a seed need to germinate? (Select all that apply.)
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Seeds need water, oxygen and warmth — not light at first.
Germination needs ______ to activate the seed's enzymes.
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Water, oxygen and warmth start germination.
What a seed needs to germinate
- Germination 萌发 is a seed starting to grow. It needs water, oxygen and a suitable temperature.
- (It does not need light at first — the energy comes from the seed's food store.)
A seed needs light to begin germinating.
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The seed uses its own food store; light is needed only later.
Why those conditions
- Water activates enzymes; oxygen is for respiration; warmth speeds the enzymes up.
- The young plant uses stored food until its leaves can photosynthesise.
Seeds don't need light to germinate. Many people assume they do, but the seed has its own food store. Light is only needed later, once the seedling must photosynthesise.
You've got it
- a pollen tube carries the male nucleus to the ovule → fertilisation
- the ovule becomes a seed, the ovary becomes a fruit
- germination needs water, oxygen and warmth (not light at first)