Sexual reporudction in plants

Question 1

During fertilisation, what does the nuclei from the pollen tube fuse with?

Answer 1

The egg cell and the polar nuclei

Question 2

Describe the process of fertilisation that takes place in flowering plants

Answer 2

idea that generative nucleus divides
to form two male gametes ;
2. by mitosis ;
3. pollen tube fuses with embryo sac /
eq ;
4. reference to double fertilisation ;
5. (one) male { gamete / nucleus }
fuses with egg (cell) nucleus ;
6. to produce diploid zygote;
7. other male nucleus fuses with two
polar nuclei ;
8. to produce triploid endosperm ;

Question 3

What is crossing over?

Answer 3

3. crossing over involves swapping of
   {sections / eq} of {chromatids
   /chromosomes} ;

Question 4

What is independent assortment?

Answer 4

. independent assortment gives rise
to {new / different / eq}
combinations of (paternal and
maternal) chromosomes ;

Question 5

Suggest the advantages to flowering plants of increased pollen tube growth

Answer 5

1. more likely to reach the ovule /eq ;
2. fertilisation more likely to occur /eq ;
3. idea of fertilisation in shorter time period ;