Genetics Blackout Review

Draw an example of:

-A pair of heterozygous alleles

- A pair of homozygous dominant alleles

- A pair of homozygous recessive alleles

In domesticated dogs, hair type is controlled by two different alleles. The allele for wire hair is (H) and the allele for smooth hair is (h).

When two heterozygous dogs are crossed are crossed, what percentage of the offspring is expected to be homozygous for smooth hair?

• 0%

• 25%

• 50%

• 75%

A genetic cross involving two unlinked genes is represented:

AaGG x aaGg

Which genotype is NOT possible in the offspring produced by the cross?

• AaGG

• Aagg

• aaGg

• aaGG

The inheritance pattern for an autosomal dominant trait is shown in the pedigree. Shaded symbols represent individuals that express the dominant trait.

Based on the pedigree, what are the most likely genotypes of individuals I-1 and I-2?

• I-1: aa

  I-2: Aa

• I-1: AA

  I-2: Aa

• I-1: Aa

  I-2: aa

• I-1: aa

  I-2: AA

In humans blood type is determined by the A, B, and O alleles. The A and B alleles are codominant to each other and dominant over the O allele. An individual with the AO genotype and an individual with the BO genotype offspring with which of the following phenotypes?

• O only

• A or B only

• A, B, or O only

• A, AB, or O

Mice have two unlinked allele pairs that affect fur color. The table shows how allele pairs affect fur color. The term "agouti" describes fur with pigmentation that changes in each hair from the shaft to the tip, giving the fur a banded appearance. Mice with the aa allele pair are alpine, regardless of the second allele-pair combination.

What is the probability of albinism in the offspring of a cross between two mice with AaBb alleles?

• 1/16

• 3/16

• 4/16

• 9/16

When asked about homozygous and heterozygous alleles, we know that homozygous looks like this: ​ (a)   and heterozygous will look like this: ​ (b)   . If someone is homozygous dominant for a trait, their genotype will look like:​ ​ (c)   . If someone is homozygous recessive for a trait, their genotype will look like: ​ ​ (d)   . We also know the term used to describe the physical trait is a ​ (e)   .

• phenotype
• heterozygous
• aa or AA