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 account for the reappearance of traits after they disappeared in one generation.

Question 2

A man with type AB blood and a woman with type O blood have a child. What is the probability that their child will have type A blood? Use the following alleles: $$I^A$$, $$I^B$$, and $$i.$$

Accepted Answer

$$0.5$$

Question 3

Which of the following scenarios is an example of pleiotropy?

Accepted Answer

A single gene mutation causes changes in hemoglobin structure, anemia, and organ damage.

Question 4

In a dihybrid cross between two individuals heterozygous for both seed color (Yy) and seed shape (Rr), what is the expected phenotypic ratio in the F2 generation according to Mendel's law of independent assortment?

Accepted Answer

$$9:3:3:1$$

Question 5

A woman who is a carrier for an X-linked recessive disorder and a man who does not have the disorder have a son. What is the probability that their son will have the disorder?

Accepted Answer

$$0.5$$

Question 6

Which of the following best describes the chromosomal theory of inheritance?

Accepted Answer

Genes occupy specific loci on chromosomes, and chromosomes undergo segregation and independent assortment during meiosis.

Question 7

If two genes are located close together on the same chromosome, which of the following is most likely to be observed?

Accepted Answer

The genes tend to be inherited together and do not assort independently.

Question 8

A testcross is performed between a pea plant with an unknown genotype for flower color (purple is dominant to white) and a homozygous recessive plant. If all offspring have purple flowers, what is the genotype of the unknown parent?

Accepted Answer

Homozygous dominant

Question 9

Which of the following is an example of incomplete dominance?

Accepted Answer

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

Question 10

Which rule would you use to calculate the probability of obtaining a plant with yellow seeds and round shape from a dihybrid cross, given that the traits assort independently?

Accepted Answer

The rule of multiplication

Question 11

A pedigree shows that a genetic disorder appears in every generation and affects both males and females equally. Which inheritance pattern is most likely?

Accepted Answer

Autosomal dominant

Question 12

Which of the following best explains why King Henry VIII was incorrect in blaming his wives for not producing sons?

Accepted Answer

The male determines the sex of the offspring because he can contribute either an X or a Y chromosome.

Question 13

Which of the following is a real-world example of polygenic inheritance?

Accepted Answer

Human height, which is influenced by the additive effects of multiple genes.

Question 14

If the recombination frequency between two genes is $$12\%$$, what does this indicate about their physical relationship on a chromosome?

Accepted Answer

The genes are relatively close together on the same chromosome.

Question 15

Which of the following statements about sex-linked inheritance is correct?

Accepted Answer

Males are more likely to express X-linked recessive disorders because they have only one X chromosome.

Question 16

Which of the following best describes codominance?

Accepted Answer

Both alleles are fully expressed in the phenotype of a heterozygote.

Question 17

Carrier screening and fetal testing can provide valuable genetic information. Which of the following is a potential ethical dilemma associated with these technologies?

Accepted Answer

Deciding whether to continue a pregnancy based on genetic information.

Question 18

In some reptiles, the sex of the offspring is determined by the temperature at which eggs are incubated. What is a possible consequence of global climate change for these species?

Accepted Answer

It may alter the sex ratio by favoring the development of one sex over the other.

Question 19

A genetic map based on recombinant frequencies is called a:

Accepted Answer

Linkage map

Question 20

Which of the following statements about the inheritance of sickle-cell disease is correct?

Accepted Answer

Carriers of the sickle-cell allele are resistant to malaria.

Patterns of Inheritance: Mendelian and Chromosomal Genetics

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