Genetics review

What is the probability of having an offspring with a recessive trait if both parents are heterozygous for that trait?

• 25%

• 50%

• 75%

• 100%

In a Punnett square, what does a capital letter represent?

• A recessive trait

• A dominant trait

• A co-dominant trait

• An incomplete dominant trait

Which of the following best describes co-dominance?

• Only one allele is expressed in the phenotype.

• Both alleles are fully expressed in the phenotype.

• A blend of the alleles is expressed in the phenotype.

• Neither allele is expressed in the phenotype.

What is the expected phenotype ratio of a cross between two heterozygous parents showing incomplete dominance?

• 1:2:1

• 3:1

• 9:3:3:1

• 2:1

Which blood type is the recessive blood type?

• AB

• B

• O

• A

In humans, colorblindness is a sex-linked trait. A colorblind woman and a non-colorblind man have a daughter. What would her genotype be?

• XCXc

• XcXc

• XCY

• XcY

If a plant species exhibits incomplete dominance for flower color, and R represents red, W represents white, what color flowers would an RW plant have?

• Red

• White

• Pink

• Purple

What is the genotype of a person with AB blood type?

• AA or AO

• BB or BO

• OO

• AB

Which of the following is not true of a recessive trait?

• You will see it with only one copy.

• It can hide in a population.

• It needs two copies to be expressed.

• A heterozygous genotype is a carrier of the recessive trait.

What is the expected genotypic ratio of a monohybrid cross between two heterozygous parents (Aa x Aa)?

• 1:2:1

• 3:1

• 9:3:3:1

• 2:1