Question 1

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

Accepted Answer

Each individual has a pair of alleles for each trait, and these alleles separate during gamete formation so that each gamete contains only one allele from each pair.

Question 2

A heterozygous tall pea plant (Tt) is crossed with a homozygous short pea plant (tt). What is the expected phenotypic ratio of the offspring?

Accepted Answer

1 tall : 1 short

Question 3

Which of the following is an example of codominance in humans?

Accepted Answer

ABO blood type, where both $$I^A$$ and $$I^B$$ alleles are fully expressed in individuals with type AB blood.

Question 4

A man with type AB blood ($$I^A I^B) $$and a woman with type O blood ($$ii) $$have children. What are the possible blood types of their children?

Accepted Answer

Type A or Type B

Question 5

Which of the following best explains why cystic fibrosis is considered an autosomal recessive disorder?

Accepted Answer

Only individuals with two copies of the mutant allele ($$aa) $$express the disorder, while heterozygotes ($$Aa) $$are carriers but do not show symptoms.

Question 6

In a dihybrid cross between two heterozygous pea plants ($$TtGg x$$ $$TtGg$$), what is the expected phenotypic ratio among the offspring?

Accepted Answer

9:3:3:1

Question 7

A woman who is a carrier for hemophilia (an X-linked recessive disorder) has children with a man who does not have hemophilia. What is the probability that their son will have hemophilia?

Accepted Answer

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

Question 8

Which of the following statements about polygenic inheritance is correct?

Accepted Answer

Traits are governed by two or more sets of alleles, resulting in continuous variation within a population.

Question 9

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

Accepted Answer

Autosomal dominant

Question 10

Which of the following best describes pleiotropy?

Accepted Answer

A single gene affects two or more seemingly unrelated traits.

Question 11

If a woman with normal vision (but whose father was color-blind) marries a man with normal vision, what is the probability that their daughter will be color-blind? (Color blindness is X-linked recessive.)

Accepted Answer

0

Question 12

Which of the following is an example of incomplete dominance?

Accepted Answer

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

Question 13

Which of the following best explains Mendel's Law of Independent Assortment?

Accepted Answer

Alleles of different genes assort independently of one another during gamete formation.

Question 14

A man with Huntington disease (autosomal dominant) has a child with a woman who does not have the disease. What is the probability that their child will have Huntington disease if the man is heterozygous?

Accepted Answer

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

Question 15

Which of the following is true about X-linked recessive disorders?

Accepted Answer

More males than females are affected because males have only one X chromosome.

Question 16

A testcross is used to determine the genotype of an individual with a dominant phenotype. Which cross would you perform?

Accepted Answer

Cross the individual with a homozygous recessive individual.

Question 17

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

Accepted Answer

Genotype refers to the alleles an individual has for a specific trait, while phenotype refers to the physical appearance of the individual.

Question 18

Which of the following is a real-world example of a polygenic trait influenced by both genetics and environment?

Accepted Answer

Human skin color, which shows continuous variation and is affected by sun exposure.

Question 19

Which of the following scenarios demonstrates incomplete penetrance?

Accepted Answer

An individual inherits a dominant allele for polydactyly but does not exhibit extra digits.

Question 20

Which of the following best explains why two parents with a dominantly inherited disorder can have an unaffected child?

Accepted Answer

Both parents are heterozygous, and the child inherits the recessive allele from each parent.

Mendelian Patterns of Inheritance: Study Notes CH11

Guida di studio - Domande di pratica

Study guide - Flashcard