Genetics interactions

Question 1

Incomplete dominance

Answer 1

Heterozygotes show an intermediate phenotype

Question 2

Co-dominance

Answer 2

heterozygotes show phenotype of both alleles

Question 3

Multiple alleles

Answer 3

There may be more than two alleles for a gene

Question 4

Pleiotropy

Answer 4

One gene contributes to more than one trait

Question 5

Lethal alleles

Answer 5

can cause skewed phenotypic ratios

indicates an essential gene

Question 6

What is an example of complications of dominance and pleiotropy?

Answer 6

sickle cell syndrome

Question 7

What are the A,B, C,D an dS gene?

Answer 7

A = determines distribution of pigment in hair
B - determine colour of pigment in hair
C = permits colour expression
D = controls intensity of pigment specified by other genes
S = controls distribution of pigment

Question 8

Epistasis

Answer 8

A gene interaction in which the effects of an allele at one gene hide the effects of alleles at another gene

Question 9

Penetrance

Answer 9

measures the percent of individuals with a given genotype who exhibit the phenotype associated with genotype

Question 10

Expressivity

Answer 10

measures the extent to which a given genotype is expressed at phenotypic level

Question 11

Complementation tests

Answer 11

determine if a phenotype arises from mutations in the same or separate genes