Question 1

Which of the following best explains why Mendel chose the garden pea (Pisum sativum) as his model organism for studying inheritance?

Accepted Answer

It has many easily distinguishable traits and can be artificially crossbred.

Question 2

In Mendel’s monohybrid cross between true-breeding purple-flowered and white-flowered pea plants, all F1 offspring had purple flowers. What does this result demonstrate?

Accepted Answer

The purple allele is dominant over the white allele.

Question 3

If two heterozygous tall pea plants (Tt) are crossed, what is the expected phenotypic ratio of tall to dwarf plants in the F2 generation?

Accepted Answer

$$3:1$$

Question 4

Which of Mendel’s postulates is illustrated by the observation that a plant with genotype Ww produces gametes with either W or w alleles, but not both?

Accepted Answer

Segregation of alleles during gamete formation.

Question 5

A pea plant with genotype GgWw can produce which of the following gametes?

Accepted Answer

GW, Gw, gW, gw

Question 6

In a dihybrid cross between two heterozygous plants (YyRr x YyRr), what is the expected phenotypic ratio in the F2 generation?

Accepted Answer

$$9:3:3:1$$

Question 7

Which equation correctly represents the chi-square ($$\$$chi^2$$) test used to evaluate genetic data?

Accepted Answer

$$\$$chi^2$$ = \sum \frac{(o-e)^2$}{e}$$

Question 8

A testcross is performed between a pea plant with yellow, round seeds of unknown genotype and a plant with green, wrinkled seeds. If the unknown plant is heterozygous for both traits, what phenotypic ratio is expected among the offspring?

Accepted Answer

$$1:1:1:1$$

Question 9

If the probability of a pea plant producing a yellow seed is $$3/4$$ and the probability of producing a round seed is $$3/4$$, what is the probability of producing a yellow, round seed?

Accepted Answer

$$9/16$$

Question 10

How many genetically distinct gametes can be produced by an organism with the genotype AaBbCc?

Accepted Answer

$$2^3 = 8$

Question 11

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

Accepted Answer

Genes are located on chromosomes, which segregate and assort independently during meiosis.

Question 12

In a cross between Dd (tall) and dd (dwarf) pea plants, what is the expected genotypic ratio among the offspring?

Accepted Answer

$$1 Dd : 1 dd$$

Question 13

A researcher observes 740 purple and 260 white-flowered plants in a monohybrid cross (expected 3:1 ratio, total 1000 plants). What is the expected number of white-flowered plants?

Accepted Answer

250

Question 14

Which of the following is a consequence of independent assortment during meiosis?

Accepted Answer

Production of genetically dissimilar gametes

Question 15

If a plant with genotype WW is crossed with a plant with genotype ww, what will be the genotype and phenotype of the F1 generation?

Accepted Answer

Genotype: Ww; Phenotype: dominant trait

Question 16

A trihybrid cross (AaBbCc x AaBbCc) produces how many different phenotypic classes in the F2 generation, assuming independent assortment and complete dominance?

Accepted Answer

8

Question 17

Which law states that the probability of two independent events occurring together is the product of their individual probabilities?

Accepted Answer

Product law

Question 18

In a pedigree analysis, which pattern would suggest a trait is dominant?

Accepted Answer

The trait appears in every generation and affected individuals have at least one affected parent.

Question 19

If the null hypothesis is rejected in a chi-square test of genetic data, what does this indicate?

Accepted Answer

The observed deviation is not due to chance alone.

Question 20

What is the probability that two heterozygous parents (Aa x Aa) will have two children, both of whom are homozygous recessive (aa)?

Accepted Answer

$$1/16$$

CH3: Mendelian Genetics: Principles, Experiments, and Analysis

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