Question 1

Which of the following best describes the process and significance of crossing over during meiosis?

Accepted Answer

Crossing over occurs during prophase I and increases genetic variation by exchanging DNA between homologous chromosomes.

Question 2

A human karyotype is used to:

Accepted Answer

Visualize and count the number and structure of chromosomes, including autosomes and sex chromosomes.

Question 3

Which of the following best explains Mendel’s Law of Independent Assortment?

Accepted Answer

Alleles of different genes assort independently of one another during gamete formation, provided the genes are on different chromosomes.

Question 4

A woman with blood type AB and a man with blood type O have a child. Which blood types are possible for their child?

Accepted Answer

A or B

Question 5

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

Accepted Answer

$$9:3:3:1$$

Question 6

A geneticist is studying a trait that shows incomplete dominance. If a red-flowered plant ($$RR) is $$crossed with a white-flowered plant ($$WW$$), what will be the phenotype of the $$F_1$$ generation?

Accepted Answer

All pink flowers

Question 7

Which of the following scenarios best illustrates pleiotropy?

Accepted Answer

A single gene affects both eye color and susceptibility to a disease.

Question 8

A pedigree shows a trait that appears mostly in males and skips generations. Which inheritance pattern is most likely?

Accepted Answer

X-linked recessive

Question 9

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

Accepted Answer

Genotype refers to the alleles present, while phenotype refers to the observable traits.

Question 10

A test cross is performed between a plant with an unknown genotype showing the dominant phenotype 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 11

Which of the following is an example of polygenic inheritance?

Accepted Answer

Height in humans

Question 12

If a gene is located on the X chromosome and shows X inactivation, what is a likely outcome in a female mammal?

Accepted Answer

One X chromosome is randomly inactivated in each cell, leading to mosaic expression of X-linked genes.

Question 13

Which of the following best explains the concept of epigenetics?

Accepted Answer

Heritable changes in gene expression that do not involve changes to the DNA sequence.

Question 14

A couple is concerned about genetic disorders in their unborn child. Which screening test involves sampling amniotic fluid to analyze fetal chromosomes?

Accepted Answer

Amniocentesis

Question 15

Which of the following best describes the outcome of random alignment of homologous chromosomes on the metaphase plate during meiosis I?

Accepted Answer

It increases genetic variation by producing different combinations of maternal and paternal chromosomes.

Question 16

In a family pedigree, a trait is present in every generation and affects both males and females equally. What is the most likely mode of inheritance?

Accepted Answer

Autosomal dominant

Question 17

Which scenario best illustrates codominance?

Accepted Answer

A flower with red and white patches from parents with red and white flowers.

Question 18

If two genes are linked, which of the following is most likely to occur?

Accepted Answer

They tend to be inherited together unless crossing over occurs between them.

Question 19

Which of the following best describes the Law of Segregation?

Accepted Answer

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

Question 20

A woman who is a carrier for an X-linked recessive disorder and a man who is unaffected have a son. What is the probability that their son will have the disorder?

Accepted Answer

$$0.5$$

Meiosis and Genetics: Key Concepts and Review

Study Guide - Practice Questions

Study Guide - Flashcards