Book 8.3

Question 1

When the phenotype of the heterozygote is intermediate between both homozygotes, the situation is called _______ _______.

Answer 1

Incomplete dominance

Question 2

sickle cell disease _________ dominance.

Answer 2

Incomplete

Question 3

oxygen-carrying protein in red blood cells

Answer 3

Hemoglobin

Question 4

Under conditions of _______ stress, mutant hemoglobin molecules will clump together, forming long chains that distort cells into a sickle shape, causing them to clog small blood vessels in the body.

Answer 4

Oxygen

Question 5

The sickle-cell allele is described as ________ dominant because the mutant protein is still produced.

Answer 5

Incompletely

Question 6

two different alleles of a gene are both expressed in an individual is known as _________.

Answer 6

Co-dominance

Question 7

When a heterozygote has a phenotype intermediate between two homozygotes, the allele is said to be _________ dominant.

Answer 7

Incompletely

Question 8

In sickle cell anemia, the disease- causing allele is not nonfunctional, it is present in ______ form.

Answer 8

mutated

Question 9

The alleles that determine A and B blood type are best described as ________, meaning that both are expressed in the heterozygote.

Answer 9

Co-dominant

Question 10

The ABO blood system also displays other common phenomenon- that any gene may more than ___ alleles.

Answer 10

2

Question 11

Individuals with type O blood carry two copies of the _____ allele for blood type.

Answer 11

Recessive