Mid-Unit Genetics Review

An allele is:

• another word for a gene

• a homozygous genotype

• a heterozygous phenotype

• one possible variation of a gene

Phenotype refers to the ___________________ of an individual.

• genetic makeup

• physical appearance

• recessive alleles

What genotype is made of a dominant and a recessive allele?

• Homozygous dominant

• Homozygous recessive

• Heterozygous

• None of the above

A small section of DNA that codes for a specific protein, which makes a specific phenotype of a trait is called a _____________________.

• gene

• chromosome

• dominant

• heterozygote

Which phenotype is recessive?

• Purple

• White

• Both

• Neither

Which of the following is an example of an allele?

• Bb

• b

• hair texture

• curly

How many different phenotypes for the earlobes trait are shown here?

• 6

• 4

• 2

• 0

What is the probability of the offspring being heterozygous?

• 0/4 = 0%

• 1/4= 25%

• 2/4 = 50%

• 3/4 = 75%

• 4/4 = 100%

This Punnett Square is for the sickle cell anemia trait.

The sickle cell allele is recessive.

What is the probability of the offspring having sickle cell anemia?

• 0/4 = 0%

• 1/4 = 25%

• 2/4 = 50%

• 3/4 = 75%

• 4/4 = 100%

Describe the phenotype of the dog's fur color trait.