Question 1

Which of the following best explains why the blending hypothesis was rejected in favor of Mendel’s particulate theory of inheritance?

Accepted Answer

Because blending could not explain how traits that disappear in one generation can reappear in later generations.

Question 2

A pea plant with genotype $$Pp is $$crossed with another $$Pp$$ plant. According to Mendel’s law of segregation, what is the expected phenotypic ratio in the offspring if $$P is $$dominant to $$p$$?

Accepted Answer

$$3:1 ($$dominant:recessive)

Question 3

Which phase of meiosis provides the physical basis for Mendel’s law of segregation?

Accepted Answer

Anaphase I

Question 4

A woman with type O blood and a man with type AB blood have children. Which of the following blood types could their children have?

Accepted Answer

Type A or Type B

Question 5

Which of the following best describes pleiotropy?

Accepted Answer

A single gene influences multiple phenotypic characters.

Question 6

In a dihybrid cross between two individuals with genotype $$AaBb$$, what is the probability of producing an offspring with genotype $$AABB$$? (Assume independent assortment.)

Accepted Answer

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

Question 7

A geneticist observes that two genes do not assort independently and are often inherited together. What is the most likely explanation?

Accepted Answer

The genes are located close together on the same chromosome (linked genes).

Question 8

A woman who is a carrier for hemophilia (an X-linked recessive disorder) and a man without hemophilia have a son. What is the probability that their son will have hemophilia?

Accepted Answer

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

Question 9

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

Accepted Answer

A cross between red-flowered and white-flowered snapdragons produces pink-flowered offspring.

Question 10

If a man with genotype $$AaBbCc$$ mates with a woman with genotype $$AaBbCc$$, what is the probability that their child will have genotype $$AABBCC$$? (Assume independent assortment.)

Accepted Answer

$$\frac{1}{64}$$

Question 11

Which of the following statements about polygenic inheritance is correct?

Accepted Answer

It results from the additive effects of two or more genes on a single phenotypic character.

Question 12

A testcross is performed between a plant with an unknown genotype and a homozygous recessive plant. If all offspring display the dominant phenotype, what is the genotype of the unknown parent?

Accepted Answer

Homozygous dominant

Question 13

Which of the following best explains why Mendel was able to ignore environmental influences in his pea plant experiments?

Accepted Answer

He used controlled conditions that minimized environmental variation.

Question 14

Which of the following is true regarding the inheritance of X-linked recessive disorders in humans?

Accepted Answer

Males are more likely to express the disorder because they have only one X chromosome.

Question 15

Which of the following best describes the chromosomal basis for Mendel’s law of independent assortment?

Accepted Answer

The random orientation of homologous chromosome pairs during metaphase I of meiosis.

Question 16

A geneticist finds that two genes have a recombination frequency of 10%. What does this indicate about their location?

Accepted Answer

They are relatively close together on the same chromosome.

Question 17

Which of the following is an example of codominance?

Accepted Answer

A person with genotype $$I^A I^B$$ has type AB blood, expressing both A and B antigens.

Question 18

A woman with normal vision (whose father was colorblind) marries a colorblind man. What is the probability that their first child will be a colorblind son? (Colorblindness is X-linked recessive.)

Accepted Answer

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

Question 19

Which of the following statements about the Y chromosome is correct?

Accepted Answer

It is passed virtually unchanged from father to son, making it useful for tracing paternal ancestry.

Question 20

Which of the following is a real-world example of how environmental factors can influence genetic traits?

Accepted Answer

The sex of some reptiles is determined by the temperature at which eggs are incubated.

Patterns of Inheritance: Mendelian Genetics and Beyond

Study Guide - Practice Questions

Study Guide - Flashcards