6F 6G Quiz

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?

• 0%

• 25%

• 50%

• 75%

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 can produce offspring with which of the following phenotypes?

• O only

• A or B only

• A, B or O only

• A, B, AB or O

In some chickens, the gene for feather color is controlled by codominance. The allele for black is B and the allele for white is W. The heterozygous phenotype is known as erminette.

 

If two erminette chickens were crossed, what is the probability that they would have a black chick?

• 0%

• 25%

• 50%

• 75%

Albinism is an autosomal recessive condition. Which circle graph shows the genotype probability when an albino female mates with a male that is heterozygous for the albinism trait?

• F

• G

• H

• J

Gametes produced by an organism contain a combination of genes from that organism. In every gamete, this combination is-

• Different due to independent assortment during mitosis

• The same because chromosomes are copied prior to meiosis

• Different due to DNA replication prior to mitosis

• The same because it is created from the same DNA

Chickens can have different types of feathers. Frizzled feathers curl towards a chicken’s head. Assume that feather type is determined by a single gene and that the allele for frizzled feathers is dominant over the allele for straight feathers.

 

In a cross between two chickens with straight feathers, what percentage of the offspring can be expected to have frizzled feathers?

• 0%

• 25%

• 50%

• 75%

A cellular process is shown.

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

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

• Offspring will no longer express traits from previous generations.

• Gametes will contain new allele combinations.

• Chromatids will have less genetic variety.

In cattle the allele for cloven hooves (H) is dominant over the allele for mule-foot hooves (h).

What is the probability of cloven hooves in the offspring of parents that are heterozygous for the trait?

• 0%

• 25%

• 50%

• 75%

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 –

• 12 chromosomes

• 23 chromosomes

• 46 chromosomes

• 92 chromosomes

Why do sex-linked traits appear more often in males than in females?

• Only one copy of the X chromosome is found in cells of males, but two copies are found in cells of females.  

• Replication of the X chromosome occurs often in males but rarely in females.

• Males have hormones that enhance the expression of X-linked traits.

• Males mature more slowly than females, allowing recessive traits more time to appear.