2.5 Plant Reproduction

Question 1

Stigma

Answer 1

Platform that pollen land on

Question 2

Style

Answer 2

Provides support

Question 3

Ovules

Answer 3

Found in the ovary

Question 4

Carpel(female reproductive system)

Answer 4

Contains ovary stigma and style
Ovary - ovule - nucleus - micropyle

Question 5

Nucellus

Answer 5

Contains mass of the ovule
Contains diploid megaspore

Question 6

Female gamete formation

Answer 6

Female megaspore mother cell divides by meiosis to produce four haploid cells three will disintegrate and die the remaining haploid cells grow until it fills the nucellus the megaspore divides 3 times by mitosis becoming an immature embryo sac, the cytoplasm then divides to form 7 cells( 3 antipodal cells, the ovum and 2 synergids. The remaining 2 polar nuclei stay at the centre of the mature embryo sac.

Question 7

Male gamete formation

Answer 7

Each megaspore mother cell divides twice by meiosis forming 4 haploid microspores developing into pollen grains via mitosis via mitosis forming 2 nuclei a tube nuclei and a generative nuclei.

Question 8

The process of fertilisation

Answer 8

Pollen grain lands on the stigma and water is absorbed causing the pollen grain to split causing the pollen tube too grow down through the tissue of stigma, style and ovary the hydrolytic enzymes on the tip of the pollen tube digests the plant tissues as the cell grows driven by the absorption of products. At the tip of the pollen tube is the tube nucleus behind the generative that divides by mitosis to produce 2 haploid nucleus that are now male gametes, the pollen tube reaches the ovule growing through the micropyle entering embryo sac. Double fertilisation happens and one of the male gametes fused with the female nucleus to form a diploid zygote and the other male gamete fuses with 2 polar nuclei to form a tripod endosperm and 5 disintegrate.