Gene Interactions

Question 1

Incomplete Dominance

Answer 1

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 2

Codominance

Answer 2

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

Question 3

Epistatic Effects

Answer 3

This is where one gene affects the expression of another gene

Question 4

Sex-linkage

Answer 4

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

Question 5

Sex-influenced

Answer 5

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

Question 6

Multiple Alleles

Answer 6

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

Question 7

Lethal Alleles

Answer 7

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