Lesson 4 - Heredity Milestones Review Practice Questions

In pea plants, the trait for tall stems is dominant over the trait for short stems. If two heterozygous tall plants are crossed, what percentage of the offspring would be expected to have the same phenotype as the parents?

• 100%

• 75%

• 50%

• 25%

Alleles for the A and B blood cell antigens are codominant. The condition where no antigens are present on the blood cells (type O blood) is a recessive trait. Which set of parents can most likely produce a child with type O blood?

• one parent with type AB blood, and the other parent with type A blood

• one parent with type AB blood and the other parent with type O blood

• one parent with heterozygous type A blood, and the other parent with type O blood

• one parent with homozygous type A blood, and the other parent with homozygous type B blood

One of the parents of a child has phenylketonuria (PKU), which is caused by recessive alleles. The other parent does not have the PKU alleles. What is the chance that the couple will have a child with phenylketonuria?

• 0%

• 50%

• 75%

• 100%

Hitchhiker's thumb (H) is dominant to no hitchhiker's thumb (h). A woman who does not have hitchhiker's thumb marries a man who is heterozygous for hitchhiker's thumb. What is the probable genotypic ratio of their children?

• 0% Hh: 100% hh

• 50% Hh: 50% hh

• 75% Hh: 25% hh

• 100% Hh: 0% hh

A pair of male Holsteins (black-and-white) calves that have the same parents display many similarities but also exhibit some variations. Which process best explains these variations?

• independent assortment

• sex linkage

• dominance

• gene kinkage

This diagram shows a diploid cell with two pairs of homologous chromosomes. Due to independent assortment, what is the possible genetic make-up of gametes produced by this organism?

• SsTt

• Ss, Tt

• S, s, T, t

• ST, St, sT, st

The table lists the trials for fruit color where allele R exhibits incomplete dominance over allele R ^I . Heterozygous fruit have orange phenotypes. What percent of offspring are expected to have an orange phenotype if the parent plants are orange (RN) and yellow (R'R')?

• 25%

• 50%

• 75%

• 100%

When recovering from injury, blood platelets that cover the wound are slowly replaced by newly formed skin cells. Old skin cells, with 46 chromosomes, divide to form new skin cells with 46 chromosomes. This is classified as what sort of reproductive process?

• Sexual

• Gestation

• Asexual

• Binary Fission

Female cattle that have white coats are crossed with male cattle that have read coats. Both male and female offspring have roan coats, which are coats with both red hairs and white hairs. Which of the following BEST describes the genetics of coat color in the cattle?

• The red and white alleles are sex-linked.

• The red and white alleles are codominant.

• The red allele is recessive to the white allele.

• The red allele is dominant to the white allele.

Mitosis and meiosis are processes involved in cellular reproduction. Which of the following describes an event that results from mitosis but NOT meiosis

• two stages of cell division

• replication of cellular genetic material

• daughter cells that are identical to the parent cell

• four daughter cells that are produced from each parent cell