Gene Interactions

Question 1

What are the 7 types of gene interaction?

Answer 1

Incomplete Dominance 
Codominance 
Epistatic effects 
Sex- linkage 
Sex- influenced 
Multiple alleles 
Lethal alleles

Question 2

Describe incomplete dominance

Answer 2

Neither allele is completely dominant to the other.

This produces a new phenotype where the heterozygous animal will look different to both homozygous animals.

Question 3

Describe Codominance

Answer 3

Neither allele is completely dominant to the other. Both alleles are shown at the same time in the phenotype.

Question 4

Describe Epistatic effects

Answer 4

This is where one gene affects the expression of another gene

Question 5

Describe Sex-linkage

Answer 5

This is when genes are carried on the sex chromosomes (X or Y)

Question 6

Describe Sex- influenced

Answer 6

The phenotype depends on the gender of the animal even though the gene controlling that characteristic is not is not on the sex chromosome.
It is influenced by sex hormones.

Question 7

Describe Multiple Alleles

Answer 7

This is where three or more alternative alleles of a single gene are possible (but only two are present in an individual organism)

Question 8

Describe Lethal Alleles

Answer 8

These lead to death in the animals which have them. They can be dominant or recessive or show other interactions such as lethal white overo in horses.