Question 1

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

Accepted Answer

Each organism inherits two alleles for each gene, but only one allele from each parent is present in each gamete due to random segregation during gamete formation.

Question 2

A pea plant with genotype $$Yy ($$yellow seeds, where yellow is dominant to green) is self-fertilized. What is the expected phenotypic ratio of the offspring?

Accepted Answer

$$3:1$$ yellow to green

Question 3

Which of the following is a key reason Mendel chose pea plants for his experiments?

Accepted Answer

They naturally self-fertilize and can be easily cross-fertilized by hand.

Question 4

In a dihybrid cross between two plants heterozygous for seed shape and color ($$SsYy 	imes SsYy$$), what is the expected phenotypic ratio in the F2 generation?

Accepted Answer

$$9:3:3:1$$

Question 5

A testcross is performed between a plant with an unknown genotype showing the dominant phenotype and a homozygous recessive plant. If the unknown plant is heterozygous, what ratio of phenotypes is expected in the offspring?

Accepted Answer

$$1:1$$ dominant:recessive

Question 6

Which of the following statements about genotype and phenotype is correct?

Accepted Answer

Genotype refers to the genetic makeup, while phenotype refers to the observable traits.

Question 7

Mendel’s Law of Independent Assortment states that:

Accepted Answer

Alleles for different genes segregate independently during gamete formation.

Question 8

A plant with genotype $$Ss is $$crossed with a plant with genotype $$ss. $$What is the probability that an offspring will have the recessive phenotype?

Accepted Answer

$$0.5$$

Question 9

Which of the following best explains why Mendel did not observe blending inheritance in his experiments?

Accepted Answer

Traits were determined by discrete factors (genes) that did not blend but segregated independently.

Question 10

In a trihybrid cross ($$AaBbCc 	imes AaBbCc$$), what is the probability of obtaining an offspring that is homozygous recessive for all three genes?

Accepted Answer

$$\left(\frac{1}{4}\$$right)^3$$ = \frac{1}{64}$$

Question 11

A population of corn is produced by crossing two true-breeding lines: one with yellow kernels ($$WW) $$and one with white kernels ($$ww). $$The F1 generation is self-fertilized. What proportion of the F2 generation will have white kernels?

Accepted Answer

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

Question 12

Which of the following is an example of a continuously variable trait?

Accepted Answer

Human height

Question 13

If a plant with genotype $$Rr ($$round seeds) is self-fertilized, what is the expected genotypic ratio among the F2 offspring?

Accepted Answer

$$1:2:1 (RR$$:Rr:rr)

Question 14

Why did Mendel’s work go largely unnoticed during his lifetime?

Accepted Answer

His results were published in an obscure journal and not widely read.

Question 15

Which of the following best describes a monohybrid cross?

Accepted Answer

A cross between two individuals that differ in one trait.

Question 16

A researcher observes a 9:3:3:1 phenotypic ratio in the F2 generation of a cross. What does this indicate about the genes involved?

Accepted Answer

The genes assort independently and are located on different chromosomes.

Question 17

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 18

If the observed results of a genetic cross differ significantly from the expected results, which statistical test can be used to determine if the difference is due to chance?

Accepted Answer

Chi-square test

Question 19

In a real-world scenario, why might the observed ratios of phenotypes in a genetic cross differ from the expected Mendelian ratios?

Accepted Answer

Random chance and sampling error can cause deviations from expected ratios.

Lecture 2

Study Guide - Practice Questions

Study Guide - Flashcards