fertilisation Flashcards
1
Q
what is fertilisation?
A
nucleus of a male gamete fuses with the nucleus of a female gamete to form a zygote.
2
Q
what triggers a pollen grain to germinate?
A
when it comes into contact with the sugary fluid secreted by the mature stigma
3
Q
what occurs after pollination?
( step 1 )
A
- after pollination, the pollen grain germinates after coming into contact with the sugary fluid secreted by the mature stigma
4
Q
what happens after the pollen grain germinates?
( step 2 )
A
- a pollen tube grows out from each pollen grain, male gametes enter the pollen tube
5
Q
what does the pollen tube secrete?
A
- as the pollen tube grows. it secretes enzymes to digest the surrounding tissue of the stigma and style, allowing the pollen tube to grow
6
Q
what happens when the pollen tube reaches the ovule?
A
- the pollen tube enters the ovule through the micropyle
- inside the ovule, the tip of the pollen tube absorbs the sap and bursts to release male gametes
7
Q
what happens after the male gametes enter the ovule?
A
6 the nucleus of the male gametes fuse with the nucleus of the ovum to form the zygotes
( fertilisation )
8
Q
what does the ovary and ovule develop into after fertilisation?
A
ovary- fruit
ovule- seeds
9
Q
what happens to the flower after fertilisation?
A
- zygote becomes embryo
- petals, stigma, style, anthers wither and drop off
