SCI9 - HEREDITY - MENDELIAN - EC

In genetics, what does a genotype of Hh signify?

• Homozygous; two dominant alleles

• Homozygous; two recessive alleles

• Heterozygous; one dominant allele and one recessive allele

• Homozygous; one dominant allele and one recessive allele

A female fish is homozygous dominant for both fancy fins (F) and shiny scales (S). She is crossed with a male who is heterozygous for both traits.

What are the genotypes of these fish? (female; male)

• ffss; FFSS

• FFSs; ffss

• FFSS; FfSs

• ffSS; FfSs

In corn, smooth kernels (K) are dominant to wrinkled kernels (k).

A farmer crosses two corn plants that are heterozygous for kernel texture.

What are the odds that the offspring will have smooth kernels?

• 0/4

• 1/4

• 1/2

• 3/4

• 4/4

In rabbits, brown fur (B) is dominant to white fur (b) and short fur (H) is dominant to long fur (h).

A brown, long-furred rabbit (Bbhh) is crossed with a white, short-furred rabbit (bbHh). Both the B and H traits assort independently from one another.

What percentage of the offspring will be brown with long fur?

• 75%

• 100%

• 25%

• 50%

In monkeys, being playful (P) is dominant to being paranoid (p). A heterozygous female is crossed with a homozygous dominant male.

What are the possible genotypes of their offspring?

• PP and pp

• PP and Pp

• Only Pp

• Only PP

In cats, being awesome (A) is dominant to being average (a), and being bashful (B) is dominant to being boring (b).

A male cat that is homozygous dominant for the A trait and heterozygous for the B trait is mated with a female cat that is homozygous recessive for both. Both the A and B traits assort independently from one another.

What is the probability that they will have an offspring who is heterozygous for both traits?

• 25%

• 0%

• 50%

• 100%

Which of the following are true of dominant and recessive alleles?

• Only dominant alleles determine phenotype

• Dominant alleles mask the expression of recessive alleles

• Only recessive alleles determine phenotype

In chickens, the allele for black feathers (A) is dominant over the allele for red feathers (a).

Which of the following pairs of terms are correctly matched?

• Aa - phenotype; black feathers - genotype

• aa - genotype; red feathers - phenotype

• AA - genotype; red feathers - phenotype

• aa - phenotype; red feathers - genotype.

In humans, the ability to taste the bitter chemical PTC is controlled by a single gene. The tasting gene (T) is dominant to the non-tasting gene (t).

Which of the following genotypes is correctly labeled?

• TT - homozygous dominant

• tT - heterozygous recessive

• Tt - homozygous recessive

• tt - heterozygous dominant

A scientist crosses a homozygous red flower with a homozygous white flower. All of the resulting offspring are heterozygous with red flowers.

Assuming that flower color is controlled by a single gene, which of the following statements is most likely true?

• The allele for red flowers is on a different chromosome than the allele for white flowers.

• The allele for red flowers is recessive to the allele for white flowers.

• The allele for red flowers has mutated more times than the allele for white flowers.

• The allele for red flowers is dominant to the allele for white flowers.