Meiosis

Question 1

What is the purpose of meiosis?

Answer 1

It produces haploid gametes to prevent the chromosome number from doubling when gametes fuse at fertilisation.
Results in genetic variation

Question 2

Short meiosis model answer (4)

Answer 2

Dna is replicated in interphase before meiosis begins
In the first division there is a separation of homologous chromosomes halving the chromosome number
In the second division there is a separation of the sister chromatids
This produced four genetically different daughter cells

Question 3

What is a non disjunction?

Answer 3

When chromosomes arent seperated by the spindles. You typically end up with too many copies or not enough

Question 4

What is gene flow?

Answer 4

Different alleles being introduced into a population when individuals from another population migrate into them and reproduce

Question 5

What is crossing over?

Answer 5

While the two homologous chromosomes are joined in a bivalent sections of one chromosome are swapped with the corresponding bits of the other chromosome. There are always equal amounts crossed over so chromosomes stay the same length. This means the paternal and maternal alleles can be mixed

Question 6

What is independent assortment/segregation?

Answer 6

The chromosomes can line up in any order on the equator resulting in different possible combinations of

Question 7

What is random fertilisation?

Answer 7

Which male gamete meets the female gamete is random. This increases variation. Random fusion of gametes produces new combinations of alleles