Question 1

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

Accepted Answer

Each individual has two alleles for each gene, and these alleles separate during gamete formation so that each gamete receives only one allele.

Question 2

A pea plant with genotype Yy is crossed with another Yy plant. What is the expected phenotypic ratio of yellow to green seeds in the offspring?

Accepted Answer

$$3:1$$

Question 3

Which of the following is a key feature of autosomal dominant inheritance?

Accepted Answer

Each affected individual has at least one affected parent.

Question 4

If a plant with genotype RrYy is test-crossed with a plant with genotype rryy, what is the expected phenotypic ratio among the offspring?

Accepted Answer

$$1:1:1:1$$

Question 5

Which of the following best explains the molecular basis for the wrinkled seed phenotype in Mendel’s peas?

Accepted Answer

A dominant allele produces a starch-branching enzyme, while the recessive allele results in a loss of enzyme function due to an insertion mutation.

Question 6

A dihybrid cross between two heterozygous plants (RrYy x RrYy) produces which expected phenotypic ratio in the F2 generation?

Accepted Answer

$$9:3:3:1$$

Question 7

Which probability rule would you use to calculate the chance of obtaining a plant with genotype AaBb from a cross AaBb x AaBb?

Accepted Answer

Product rule

Question 8

In a pedigree, a trait appears in every generation and both males and females are equally affected. What is the most likely mode of inheritance?

Accepted Answer

Autosomal dominant

Question 9

A plant heterozygous for four unlinked genes (AaBbDdEe) is selfed. What proportion of the progeny will be genotypically AaBBddEe?

Accepted Answer

$$\frac{1}{64}$$

Question 10

Which of the following is NOT a critical innovation in Mendel’s experimental design?

Accepted Answer

Ignoring replicate and reciprocal crosses

Question 11

A test cross is performed between a plant with an unknown genotype for a dominant trait and a homozygous recessive plant. If all offspring display the dominant phenotype, what is the genotype of the unknown parent?

Accepted Answer

Homozygous dominant

Question 12

Which equation represents the chi-square statistic used to compare observed and expected genetic ratios?

Accepted Answer

$$\$$chi^2$$ = \sum \frac{(O - E)^2$}{E}$$

Question 13

Which of the following best describes the molecular basis for the yellow seed color in Mendel’s peas?

Accepted Answer

The dominant allele produces an enzyme that breaks down chlorophyll, turning seeds yellow.

Question 14

If two heterozygous tall pea plants (Tt) are crossed, what is the probability that an offspring will be short?

Accepted Answer

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

Question 15

Which of the following statements about Mendel’s Law of Independent Assortment is correct?

Accepted Answer

It states that alleles of different genes assort independently during gamete formation.

Question 16

A pedigree shows a trait that appears only among siblings, not in every generation, and both sexes are equally affected. What is the most likely mode of inheritance?

Accepted Answer

Autosomal recessive

Question 17

Which of the following is an example of a dichotomous trait studied by Mendel?

Accepted Answer

Seed color: yellow or green

Question 18

If the probability of a plant having yellow seeds is $$\frac{3}{4}$$ and the probability of having round seeds is $$\frac{3}{4}$$, what is the probability of a plant having both yellow and round seeds (assuming independent assortment)?

Accepted Answer

$$\frac{9}{16}$$

Question 19

Which of the following best describes a test cross?

Accepted Answer

A cross between an individual of unknown genotype and a homozygous recessive individual

Question 20

A plant with genotype GgRr is test-crossed. What phenotype ratios are expected among the progeny?

Accepted Answer

$$1:1:1:1$$

Transmission Genetics: Mendelian Principles and Probability in Genetic Analysis

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