Question 1

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

Accepted Answer

Organisms have two copies of each gene, which randomly segregate into gametes, so each gamete receives only one copy.

Question 2

In Mendel’s pea plant experiments, what was the observed phenotypic ratio in the F2 generation of a monohybrid cross?

Accepted Answer

$3:1$

Question 3

A plant with genotype $Aa$ is self-fertilized. What is the expected genotypic ratio among the offspring?

Accepted Answer

$1 AA : 2 Aa : 1 aa$

Question 4

Which statement about Mendel’s choice of pea plants is correct?

Accepted Answer

Pea plants are annual, self-fertilizing, and can be easily manipulated for controlled crosses.

Question 5

If a plant with the dominant phenotype is crossed with a homozygous recessive plant and half the offspring show the recessive phenotype, what is the genotype of the dominant parent?

Accepted Answer

Heterozygous

Question 6

In a dihybrid cross between $SsYy$ plants, what is the expected phenotypic ratio in the F2 generation?

Accepted Answer

$9:3:3:1$

Question 7

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

Accepted Answer

Alleles for different genes segregate independently during gamete formation.

Question 8

A true-breeding round-seeded pea plant ($RR$) is crossed with a true-breeding wrinkled-seeded plant ($rr$). What will be the genotype and phenotype of the F1 generation?

Accepted Answer

Genotype: $Rr$; Phenotype: round

Question 9

Which of the following is a correct application of the rules of probability in predicting the outcome of a genetic cross?

Accepted Answer

The probability of two independent events both occurring is the product of their individual probabilities.

Question 10

A plant with genotype $AaBb$ is self-fertilized. What fraction of the offspring are expected to be homozygous recessive for both traits ($aabb$)?

Accepted Answer

$1/16$

Question 11

Which of the following best describes a gene from a molecular perspective?

Accepted Answer

A gene is a segment of DNA that contains the information to express a protein that performs a function in the cell or body.

Question 12

In a trihybrid cross ($AaBbCc$ x $AaBbCc$), what is the probability of obtaining an offspring with genotype $aabbcc$?

Accepted Answer

$1/64$

Question 13

Which of the following is NOT a reason Mendel’s pea plant experiments were successful?

Accepted Answer

He studied traits controlled by multiple genes with continuous variation.

Question 14

A researcher performs a chi-square test to compare observed and expected ratios in a genetic cross. What is the primary purpose of this test?

Accepted Answer

To assess whether deviations from expected ratios are due to random chance.

Question 15

If two heterozygous plants ($Aa$) are crossed, what is the probability that an offspring will be homozygous recessive ($aa$)?

Accepted Answer

$1/4$

Question 16

Which of the following statements about alleles is correct?

Accepted Answer

Alleles are different versions of a gene that can result in different phenotypes.

Question 17

In a dihybrid cross ($AaBb$ x $AaBb$), what is the expected proportion of offspring with genotype $A_B_$ (where _ means any allele)?

Accepted Answer

$9/16$

Question 18

Which of the following is a real-world application of Mendelian genetics?

Accepted Answer

Using genetic crosses to predict the likelihood of inheriting a genetic disease.

Question 19

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

Accepted Answer

Homozygous dominant

Question 20

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

Accepted Answer

Genotype is the genetic makeup of an organism, which determines its phenotype, the observable traits.

Mendelian Genetics Review: Principles, Experiments, and Applications

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