Question 1

Which of the following best describes Mendel’s Law of Segregation?

Accepted Answer

Alleles for a heritable character separate during gamete formation and end up in different gametes.

Question 2

A pea plant with genotype $$Pp ($$where $$P is $$dominant for purple flowers and $$p is $$recessive for white flowers) is self-pollinated. What is the probability that an offspring will have white flowers?

Accepted Answer

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

Question 3

Which of the following scenarios is an example of incomplete dominance?

Accepted Answer

A cross between red and white snapdragons produces pink offspring.

Question 4

In a dihybrid cross between two $$YyRr$$ pea plants (where $$Y = $$yellow, $$y = $$green, $$R = $$round, $$r = $$wrinkled), what is the probability of obtaining an offspring with genotype $$yyrr$$?

Accepted Answer

$$\frac{1}{16}$$

Question 5

Which of the following best explains why dominant alleles are not necessarily more common in a population than recessive alleles?

Accepted Answer

Dominant alleles can be rare due to mutation or selection, as seen in polydactyly.

Question 6

A genetic counselor is working with a couple, both of whom have a sibling affected by a rare recessive disorder. What is the probability that their child will have the disorder? (Assume both sets of parents are carriers.)

Accepted Answer

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

Question 7

Which of the following is an example of pleiotropy?

Accepted Answer

The gene for sickle-cell disease causing multiple symptoms such as anemia, pain, and organ damage.

Question 8

In Labrador retrievers, coat color is determined by two genes: one for pigment color ($$B = $$black, $$b = $$brown) and one for pigment deposition ($$E = $$color, $$e = no $$color). What is the expected phenotypic ratio in the F2 generation from a cross of two $$BbEe$$ dogs?

Accepted Answer

9 black : 3 chocolate : 4 yellow

Question 9

A woman with blood type $$AB$$ and a man with blood type $$O$$ have a child. What are the possible blood types of their child?

Accepted Answer

A or B

Question 10

Which of the following best describes polygenic inheritance?

Accepted Answer

Multiple genes independently affect a single trait, resulting in continuous variation.

Question 11

If a plant with genotype $$Pp is $$testcrossed with a $$pp$$ plant, what proportion of the offspring will have purple flowers?

Accepted Answer

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

Question 12

Which of the following is a multifactorial trait?

Accepted Answer

Skin color in humans, influenced by both genes and environment.

Question 13

A man with genotype $$Ii ($$where $$I is $$the dominant allele for the enzyme that adds A carbohydrate to red blood cells, and $$i is $$the recessive allele) and a woman with genotype $$IBi$$ have a child. What is the probability that the child will have blood type O?

Accepted Answer

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

Question 14

Which of the following statements about Mendel’s experiments is FALSE?

Accepted Answer

Mendel used pea plants because they had a long generation time.

Question 15

A pedigree shows a trait that appears in every generation and affects both males and females equally. What is the most likely mode of inheritance?

Accepted Answer

Autosomal dominant

Question 16

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

Accepted Answer

The inheritance of seed color does not affect the inheritance of seed shape in pea plants.

Question 17

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

Accepted Answer

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

Question 18

Which of the following is an example of codominance?

Accepted Answer

A person with genotype $$IAIB$$ has both A and B carbohydrates on their red blood cells.

Question 19

Which of the following best describes the relationship between genotype and phenotype?

Accepted Answer

Phenotype is determined by genotype and environmental influences.

Mendel and the Gene Idea: Principles of Inheritance

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