Genetics test review

What are an individual's traits determined by?

(a)  

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?

(a)  

Brown fur is dominant over white fur in dogs. Two white dogs are crossed. What are all possible phenotypes of the puppies?

• all white

• all brown

• white and brown

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%

Red and white flowers cross and produce pink flowers. (Incomplete dominance). If two pink flowers are crossed, show all possible genotypes of the offspring.

• RW

• RW,WW

• WW,RR

• RR,RW,WW

A father is heterozygous for right-handedness. The mother is homozygous for right-handedness. What percent of the children are expected to be homozygous for right-handedness?

• 50%
• 25%

• 75%

• 100%

An organism’s genetic makeup; the pair of alleles for a trait is called a(n)

• dominant trait

• genotype

• phenotype

• recessive trait

Two identical alleles for a trait is known as

• homozygous

• heterozygous

• mutation

• codominance

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

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.