Question 1

Which of the following best describes the difference between a character and a trait in Mendelian genetics?

Accepted Answer

A character is a heritable feature that varies among individuals, while a trait is a specific variant of that character.

Question 2

Why were pea plants ideal for Mendel's genetic experiments?

Accepted Answer

They have a short generation time, produce many offspring, and their mating can be controlled.

Question 3

Mendel's law of segregation states that:

Accepted Answer

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

Question 4

If a pea plant with genotype Pp is self-pollinated, what is the expected phenotypic ratio of purple to white flowers in the offspring?

Accepted Answer

$$3:1$$

Question 5

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 display the recessive phenotype.

Question 6

In a dihybrid cross between two individuals with genotype YyRr, what is the probability of obtaining an offspring with genotype yyrr?

Accepted Answer

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

Question 7

Which of the following is an example of incomplete dominance?

Accepted Answer

A cross between red and white snapdragons produces pink offspring.

Question 8

Which statement about codominance is correct?

Accepted Answer

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

Question 9

A man with blood type AB marries a woman with blood type O. What are the possible blood types of their children?

Accepted Answer

A or B

Question 10

Which of the following best describes pleiotropy?

Accepted Answer

A single gene affects multiple phenotypic traits.

Question 11

In Labrador retrievers, coat color is determined by two genes. One gene determines pigment color (B for black, b for brown), and the other gene (E for color, e for no color) determines whether pigment is deposited. What is the expected phenotypic ratio in the offspring of two BbEe dogs?

Accepted Answer

$$9$$ black : $$3$$ brown : $$4$$ yellow

Question 12

Which of the following is an example of polygenic inheritance?

Accepted Answer

Human skin color, which is controlled by several genes.

Question 13

Hydrangea flowers of the same genetic variety are blue in acidic soil and pink in basic soil. This is an example of:

Accepted Answer

Environmental influence on phenotype.

Question 14

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 15

If two carriers (heterozygotes) for a recessive disorder have a child, what is the probability that the child will be affected by the disorder?

Accepted Answer

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

Question 16

A couple each has a sibling with a recessively inherited disease, but neither parent nor the couple themselves are affected. What is the probability that their first child will have the disease? (Assume the disease is rare and both sets of parents are carriers.)

Accepted Answer

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

Question 17

Which of the following best explains why dominant alleles that cause lethal diseases are rare in populations?

Accepted Answer

They often result in death before reproductive age, reducing their transmission.

Question 18

Which probability rule would you use to calculate the chance of getting either a yellow or a green seed in a single cross?

Accepted Answer

Addition rule

Question 19

A woman with genotype IAi and a man with genotype IBi have a child. What is the probability that the child will have blood type O?

Accepted Answer

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

Question 20

Which of the following is a multifactorial disorder?

Accepted Answer

Heart disease, which is influenced by both genetic and environmental factors.

Chapter 14

Guida di studio - Domande di pratica

Study guide - Flashcard