Question 1

Which of the following best describes Mendel's law of segregation?

Accepted Answer

The two alleles for a heritable character separate during gamete formation and end up in different gametes.

Question 2

A pea plant with genotype $$Pp is $$crossed with another $$Pp$$ plant. What is the probability that an offspring will have white flowers?

Accepted Answer

$$\frac{1}{4}$$

Question 3

In a dihybrid cross between two $$YyRr$$ pea plants, what is the expected phenotypic ratio for the offspring?

Accepted Answer

9:3:3:1

Question 4

Which of the following is an example of incomplete dominance?

Accepted Answer

A cross between red and white snapdragons produces pink offspring.

Question 5

A man with blood type AB and a woman with blood type O have children. Which blood types are possible for their offspring?

Accepted Answer

A and B

Question 6

Which term describes a gene that affects multiple phenotypic traits, such as the sickle-cell allele?

Accepted Answer

Pleiotropy

Question 7

In Labrador retrievers, coat color is determined by two genes. If two $$BbEe$$ dogs are crossed, what is the expected ratio of black:chocolate:yellow puppies?

Accepted Answer

9:3:4

Question 8

A couple both have a sibling with a recessively inherited disease. What is the probability that their child will have the disease, assuming both are carriers?

Accepted Answer

$$\frac{1}{4}$$

Question 9

Which of the following best illustrates polygenic inheritance?

Accepted Answer

Height in humans

Question 10

If a heterozygous individual ($$Aa) $$mates with another heterozygous individual ($$Aa$$), what is the probability that their child will be a carrier for a recessive disease?

Accepted Answer

$$\frac{1}{2}$$

Question 11

Which of the following statements about dominant alleles is correct?

Accepted Answer

Dominant alleles are not necessarily more common in populations than recessive alleles.

Question 12

A testcross is used to determine the genotype of an individual with a dominant phenotype. Which result would indicate the individual is heterozygous?

Accepted Answer

Some offspring have the recessive phenotype.

Question 13

Which rule is used to calculate the probability that two independent events will occur together?

Accepted Answer

Multiplication rule

Question 14

A woman who is a carrier for cystic fibrosis ($$Ff) $$and a man who is not a carrier ($$FF) $$have a child. What is the probability that the child will be a carrier?

Accepted Answer

$$\frac{1}{2}$$

Question 15

Which of the following is an example of codominance?

Accepted Answer

A person with genotype $$I^A I^B$$ has blood type AB.

Question 16

Which scenario best illustrates the environmental impact on phenotype?

Accepted Answer

Hydrangeas grown in basic soil are pink, while those grown in acidic soil with free aluminum are blue.

Question 17

Which of the following best describes the law of independent assortment?

Accepted Answer

Alleles for different genes segregate independently during gamete formation.

Question 18

A couple both have a sibling with a recessively inherited disease. What is the probability that their child will have the disease, given each has a $$\frac{2}{3}$$ chance of being a carrier?

Accepted Answer

$$\frac{1}{9}$$

Question 19

Which of the following is a multifactorial disorder?

Accepted Answer

Heart disease

Mendel and the Gene Idea: Principles of Inheritance

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