lecture 10 & 11

Question 1

what is incomplete dominance?

Answer 1

expression of the heterozygote phenotype forms an intermediate that is distinct from either parent; combination of parental phenotypes
ex. flowers

Question 2

what is the correlation of the genotypic and phenotypic ratios in incomplete dominance?

Answer 2

they are the same

Question 3

what is codominance?

Answer 3

expression of the heterozygote phenotype results in BOTH phenotypes being expressed
ex. cows

Question 4

what is pleiotropy?

Answer 4

alleles of pleiotropic genes are transmitted the same way as alleles of single trait genes
ex. Marfan syndrome

Question 5

what is the phenotypic ratio of a recessive lethal allele?

Answer 5

2:1

Question 6

how do dominant lethal alleles persist in a population?

Answer 6

delayed expression(e.g. Huntington’s), conditional expression, penetrance(not all the people with the gene express it)