Inheritance & Variation Test Review

Who is considered the father of modern genetics?

• James Watson

• Francis Crick

• Charles Darwin

• Gregor Mendel

What does the Law of Dominance describe?

• Dominant alleles are always masked by recessive alleles

• Recessive alleles are always masked by dominant alleles

• A heterozygous phenotype will result in an intermediate blend of the two traits

• The particular gene that passes on in a pair is entirely dominant

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

• Only recessive alleles determine phenotype

• Dominant and recessive alleles can be found in the same individual

• Dominant alleles do not mask the expression of recessive alleles

• Only dominant alleles determine phenotype

In a species of flowers, having tall stems (T) is dominant to having short stems (t). Which of the following genotypes is INCORRECTLY labeled?

• TT - homozygous dominant

• tt - homozygous recessive

• Tt - homozygous dominant

• Tt - heterozygous

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; red feathers - genotype

• Aa - phenotype; black feathers - genotype

• aa - genotype; red feathers - phenotype

• AA - genotype; red feathers - phenotype

What does it mean to be a carrier?

• The individual is homozygous dominant

• The individual is heterozygous

• The individual is homozygous recessive

• The individual shows the recessive trait

In humans, the ability to roll your tongue is dominant (R) to the inability to roll your tongue, which is recessive (r). Which of the following genotype and phenotype combinations is correctly labeled?

• RR homozygous recessive - inability to roll tongue

• Rr homozygous dominant - ability to roll tongue

• Rr heterozygous - ability to roll tongue

• rr homozygous recessive - inability to roll tongue

Red eyes (R) in fruit flies are dominant over white eyes (r). What is the probability of getting an offspring with red eyes if you cross two heterozygous parents?

• 25%

• 50%

• 75%

• 100%

What is the probability of getting an offspring with white eyes if you cross a homozygous dominant parent with a heterozygous parent?

• 0%

• 25%

• 50%

• 75%

Two parents with red eyes produced a white-eyed offspring. What are the genotypes of the parents?

• RR & RR

• RR & Rr

• Rr & Rr

• rr & rr