Question 1

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

Accepted Answer

The two alleles for each trait separate during gamete formation and unite at random during fertilization.

Question 2

In a monohybrid cross between two heterozygous pea plants ($Yy 	imes Yy$), what is the expected phenotypic ratio in the F2 generation?

Accepted Answer

$3:1$

Question 3

A pea plant with genotype $Yy$ is crossed with a plant with genotype $yy$. What proportion of the offspring will have yellow seeds if yellow ($Y$) is dominant to green ($y$)?

Accepted Answer

$0.5$

Question 4

Which of the following statements about alleles is correct according to Mendel's findings?

Accepted Answer

Each individual carries two alleles for each trait, one from each parent.

Question 5

A testcross is performed to determine the genotype of a pea plant with a dominant phenotype. If the offspring are produced in a $1:1$ ratio of dominant to recessive phenotypes, what is the genotype of the parent being tested?

Accepted Answer

Heterozygous

Question 6

In Mendel's dihybrid cross ($YyRr 	imes YyRr$), what is the expected phenotypic ratio among the F2 offspring?

Accepted Answer

$9:3:3:1$

Question 7

Which of the following best explains the Law of Independent Assortment?

Accepted Answer

Different pairs of alleles segregate independently during gamete formation.

Question 8

A plant breeder wants to develop a true-breeding line for round, yellow peas. Which genotype should the breeder select?

Accepted Answer

$YYRR$

Question 9

If a pea plant with genotype $YyRr$ produces gametes, what is the expected proportion of gametes with genotype $Yr$?

Accepted Answer

$1/4$

Question 10

Which of the following is an example of a homozygous recessive genotype?

Accepted Answer

$yy$

Question 11

A geneticist observes a $3:1$ ratio of phenotypes in the F2 generation of a cross. Which of Mendel's laws does this observation support?

Accepted Answer

Law of Segregation

Question 12

In a real-world scenario, a farmer notices that crossing two varieties of peas always results in all yellow seeds in the F1 generation, but both yellow and green seeds in the F2. What does this suggest about the inheritance of seed color?

Accepted Answer

Yellow is dominant to green, and inheritance follows Mendel's Law of Segregation.

Question 13

Which of the following statements is FALSE regarding Mendel's conclusions?

Accepted Answer

Alleles blend together to form new traits.

Question 14

A pea plant with genotype $Yy$ is self-fertilized. What is the probability that an offspring will be homozygous dominant?

Accepted Answer

$1/4$

Question 15

Which of the following best defines a phenotype?

Accepted Answer

The observable characteristics of an organism.

Question 16

In a dihybrid cross, what is the probability of obtaining an offspring that is homozygous recessive for both traits ($yyrr$) from two $YyRr$ parents?

Accepted Answer

$1/16$

Question 17

Which of the following is a key feature of Mendel's experimental design that allowed him to discover the laws of inheritance?

Accepted Answer

He used pure-breeding lines and performed reciprocal crosses.

Question 18

A plant with genotype $YyRr$ is crossed with a plant with genotype $yyrr$. What proportion of the offspring will have yellow, round seeds?

Accepted Answer

$1/4$

Question 19

Which of the following best describes a heterozygous genotype?

Accepted Answer

The alleles are different for a given trait.

Question 20

In a medical genetics context, a child inherits a recessive genetic disorder even though both parents are healthy. Which of Mendel's principles explains this observation?

Accepted Answer

Law of Segregation, because both parents are likely heterozygous carriers.

Mendel’s Laws: Foundations of Classical Genetics

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