5.2 - Variations in Heredity

Question 1

Complete dominance

Answer 1

Only one allele is present, despite the presence of the other allele

Question 2

Incomplete dominance

Answer 2

Where neither allele dominates the other and both have an influence on the individual; results in partial expression of both traits. *Genotype still 1:2:1. Only affects phenotype

Example: Snapdragons. Red snapdragon and white snapdragon makes a pink snapdragon

Question 3

Co-dominance

Answer 3

Both alleles are expressed fully to produce offspring with a third (mixed) phenotype. *Genotype still 1:2:1. Only affects phenotype

Examples: Shorthorn cattle (red bull and white cow makes roan (red-and-white) cow)

Question 4

Multiple alleles

Answer 4

Traits controlled by a single gene with more than 2 alleles.

Example: ABO blood type