Question 1

Which of the following best describes Mendel's principle of segregation?

Accepted Answer

Each pair of unit factors separates randomly during gamete formation, so each gamete receives one member of each pair.

Question 2

A plant with genotype $$Dd is $$crossed with a plant with genotype $$dd. $$What is the expected phenotypic ratio among the offspring if $$D is $$dominant to $$d$$?

Accepted Answer

$$1:1 ($$dominant:recessive)

Question 3

In a dihybrid cross between two heterozygous individuals ($$RrYy 	imes RrYy$$), what is the probability of obtaining an offspring with the genotype $$rryy$$?

Accepted Answer

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

Question 4

Which of the following statements about Mendel's monohybrid crosses is correct?

Accepted Answer

The F$$_1$$ generation always displays the dominant phenotype.

Question 5

A testcross is performed between a plant of unknown genotype showing the dominant phenotype 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 6

Which of the following best explains the 9:3:3:1 phenotypic ratio observed in Mendel's dihybrid crosses?

Accepted Answer

Independent assortment of two gene pairs during gamete formation

Question 7

If a human has a haploid number $$n = 23$$, how many different types of gametes can be produced by independent assortment alone?

Accepted Answer

$$2^{23}$$

Question 8

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 9

Which of the following is a correct application of the product law in genetics?

Accepted Answer

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

Question 10

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

Accepted Answer

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

Question 11

Which of the following statements about the chromosomal theory of inheritance is correct?

Accepted Answer

Genes are located on chromosomes, which are transmitted from generation to generation.

Question 12

A couple, both heterozygous for a recessive disease allele ($$Dd$$), have a child. What is the probability that the child will be affected by the disease?

Accepted Answer

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

Question 13

Which of the following best describes a locus?

Accepted Answer

The specific location on a chromosome where a gene is found

Question 14

In a pedigree, a shaded square represents:

Accepted Answer

A male expressing the trait

Question 15

Which of the following is a key reason Mendel chose garden peas for his experiments?

Accepted Answer

They have easily distinguishable traits and can self-fertilize or be cross-fertilized.

Question 16

A geneticist is analyzing the results of a cross and wants to determine if the observed data fit the expected Mendelian ratio. Which statistical test should they use?

Accepted Answer

Chi-square test

Question 17

If a trait is controlled by a gene with two alleles, $$A ($$dominant) and $$a ($$recessive), what is the expected genotypic ratio in the F$$_2$$ generation from a monohybrid cross?

Accepted Answer

$$1:2:1 (AA$$:Aa:aa)

Question 18

Which of the following is NOT an assumption underlying Mendel's predicted genetic ratios?

Accepted Answer

All genes are linked on the same chromosome

Question 19

A woman is a carrier for an autosomal recessive disorder, and her partner is homozygous dominant. What is the probability that their child will be affected?

Accepted Answer

$$0$$

Question 20

Which of the following best describes the sum law in probability as applied to genetics?

Accepted Answer

The probability of obtaining any single outcome that can be accomplished in more than one way is equal to the sum of the individual probabilities of all such events.

Mendelian Genetics: Principles, Methods, and Applications

Study Guide - Practice Questions

Study Guide - Flashcards