14. Evolutionary Mechanisms

Question 1

what is random assortment?

Answer 1

occurs in meiosis and results in gametes that have a huge number of possible combinations of the chromosomes that originally came from the male and female parent

Question 2

what is crossing over?

Answer 2

of chromatids, occurs during meiosis and may result in pieces of chromatid being broken off and attaching to a different chromatid
- results in a changed sequence or recombination of the alleles along the resulting chromosome

Question 3

what is non- disjunction?

Answer 3

where one or more members of a chromosome pair fail to seperate during meiosis
if gametes are involved in fertilisation, the resulting embryo will have the incorrect number of chromosomes

Question 4

what is random fertilisation?

Answer 4

because each person will produce a huge amount of different sperm or eggs and because any sperm can fertilise any egg, there is almost an infinite number of possible combinations of alleles in the offspring

Question 5

What are mutations?

Answer 5

permenant changes in the dna of a chromosome and may result in totally new characteristics of an individual