Genetics test review

What fraction of individuals will be homozygous dominant?

• 1/3

• 1/2

• 2/3

• 1/4

Freckles are dominant over not having freckles. If the following cross occurred, Ff x Ff, what percentage of the offspring would you expect to NOT have freckles?

• 100%

• 75%

• 50%

• 25%

Two identical alleles for a trait is known as

• homozygous

• heterozygous

• mutation

• codominance

What are an individual's traits determined by?

In rabbits, black fur (B) is dominant over brown fur (b). If a rabbit has brown fur, what can you conclude about its genotype?

• It is BB.
• It is Bb
• It is brown
• It is bb.

What is the definition of phenotype?

• The physical expression of a trait

• The genetic combination of alleles

• A gene on the DNA strand

• A variation of a gene

How many offspring will show the recessive trait?

• 0%

• 25%

• 50%

• 75%

In humans, the ability to roll one's tongue is dominant over the inability to do so. Two parents that are both heterozygous for tongue rolling have children. What are all possible genotypes of the children?

Which of the following is homozygous dominant?

• RR

• Rr

• rR

• rr

One uppercase and one lowercase letter are alleles for what type of trait?

• Homozygous

• Heterozygous (hybrid)

• Phenotype

• Allele