Heredity Test Review

The form of a gene that is always expressed if present is the ______ form.

• recessive

• dominant

• zygote

• heterozygous

The heterozygous purple-flowering pea plants are crossed. If purple is dominant over white, what are the expected phenotypic results?

• 100% purple

• 75% purple, 25% white

• 50% purple, 50% white

• 25% purple, 75% white

If an organism inherits one dominant allele and one recessive allele for eye color, their genotype would be:

• haploid

• homozygous

• heterozygous

• homologous

Two parents have the genotype Gg for a genetic disorder caused by a recessive allele. What is the chance that any of their children will inherit the disorder?

• 25%

• 50%

• 75%

• 100%

According to the Punnett square, B represents the dominant gene for blue feathers and b represents the recessive gene for red feathers. A homozygous dominant and a homozygous recessive birds mate. What percent chance does the offspring have for red feathers?

• 100%

• 75%

• 50%

• 0%

In pigs, the allele for a wavy, rough coat (R) is dominant to the allele for a soft, fine coat (r). A rough coat boar and a soft coat sow mate. They produce several litters, 50% are rough coat and 50% are smooth coat. What must be the genotypes of the parents to create this phenotypic ratio?

• RR x rr

• Rr x rr

• RR x Rr

• Rr x Rr

Imagine two heterozygous parents. Each has a dominant allele A for brown eyes and a recessive allele for blue eyes. What would the genotypic ratio of the offspring be?

• 100% Aa

• 50% AA, 50% Aa

• 25% AA, 50% Aa, 25% aa

• 50% Aa, 50% aa

Identify the following as homozygous or heterozygous: TT

• Homozygous

• Heterozygous

Identify the following as homozygous or heterozygous: Tt

• Homozygous

• Heterozygous

Identify the following as homozygous or heterozygous: tt

• Homozygous

• Heterozygous