exam Q's

Question 1

explain why colour blindness is more common in men than women

Answer 1

-males have 1 X chromosome and females have 2
-so recessive allele is always expressed in men
-and females need 2 recessive alleles to be colour blind

Question 2

explain what is meant by a dominant allele

Answer 2

an allele that is always expressed in a phenotype

Question 3

describe in words how a 9:3:3:1 ratio might be different if the two genes were autosomally linked

Answer 3

higher proportion of heterozygous/ like parents

Question 4

explain why asexually reproducing populations will be less genetically varied than sexually reproducing populations

Answer 4

-asexual reproduction involved mitosis which produces genetically identical/ clone offspring
-sexual reproduction involves meiosis which produces genetically different offspring involving random fertilisation