Unit 9 Test Review

Achondroplasia is an inherited condition that affects the formation of bone in humans. The allele for achondroplasia (A) is dominant to the affected allele (a). If a person who is homozygous dominant has children with a person who is homozygous recessive, what percentage of their children will likely have achondroplasia?

• 0%

• 25%

• 100%

• 50%

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, what percentage of the offspring is expected to be homozygous for smooth hair?

• 50%

• 75%

• 0%

• 25%

A cellular process is shown. Which of these is the most likely result of the process shown in the diagram?

• Offspring will no longer express traits from previous generations.

• Chromatids will have less genetic variety.

• Gametes will contain new allele combinations.

• Chromosome replication will cease to avoid errors that result in mutations.

This diagram demonstrates how crossing-over contributes to genetic variety during meiosis.

• mitosis

• anaphase

• crossing-over

• DNA

Sexual reproduction in animals depends on the production of gametes. The production of gametes in animals is known as

• Meiosis

• Binary Fission

• Mitosis

• Fertilization

Human body cells each have 46 chromosomes in their nuclei. Meiosis is necessary in order to ensure that each gamete produced in the human body has ____ chromosomes.

• 23

• 46

• 92

• 69

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 (Hh * Hh) are crossed, what percentage of the offspring is expected to be homozygous for smooth hair?

• 75%

• 25%

• 50%

• 0%

A model of the genetic control of coat color in rabbits is shown. Which Punnett square represents a cross that would produce albino offspring?

• 
• 
• 
• 

Some angelfish colors are determined by codominance. Possible phenotypes and genotypes of angelfish colors are shown. What is the expected percentage of black offspring resulting from a cross between a black angelfish and a black-lace angelfish?

• 0%

• 100%

• 25%

• 50%

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