Question 1

Which process during meiosis is primarily responsible for increasing genetic variation among offspring?

Accepted Answer

Crossing over between homologous chromosomes

Question 2

A human cell has 46 chromosomes. After meiosis, how many chromosomes will each gamete contain?

Accepted Answer

$23$

Question 3

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.

Question 4

A couple are both heterozygous for two traits (AaBb). What is the expected phenotypic ratio in their offspring for a dihybrid cross?

Accepted Answer

$9:3:3:1$

Question 5

Which chromosomal mutation results in a piece of a chromosome being lost?

Accepted Answer

Deletion

Question 6

What is the genotype of a pea plant that is heterozygous for round seeds (R) and homozygous for yellow seeds (YY)?

Accepted Answer

$RrYY$

Question 7

Which syndrome is caused by nondisjunction resulting in an extra chromosome 21?

Accepted Answer

Down Syndrome

Question 8

If a child inherits two identical alleles for a trait, what is their genotype called?

Accepted Answer

Homozygous

Question 9

Which of the following is NOT a source of genetic variation in sexually reproducing organisms?

Accepted Answer

Mitosis

Question 10

A karyotype of a human female shows only one X chromosome and no second sex chromosome. What disorder does this indicate?

Accepted Answer

Turner Syndrome

Question 11

Which term describes the physical expression of a gene?

Accepted Answer

Phenotype

Question 12

During meiosis, homologous chromosomes separate during which phase?

Accepted Answer

Anaphase I

Question 13

Which process ensures that gametes have only one set of chromosomes?

Accepted Answer

Meiosis

Question 14

A child is born with 47 chromosomes, including three copies of chromosome 18. What is the name of this condition?

Accepted Answer

Edward's Syndrome

Question 15

Which of the following best explains why siblings in a family look similar but are not identical?

Accepted Answer

They receive a random combination of alleles due to independent assortment and crossing over.

Question 16

What is the probability that two heterozygous parents (Aa) will have a child with the homozygous recessive genotype (aa)?

Accepted Answer

$\frac{1}{4}$

Question 17

Which of the following is an example of a chromosomal mutation that can be detected by karyotyping?

Accepted Answer

Trisomy 21

Question 18

In a dihybrid cross between two heterozygous guinea pigs (BbLl), what fraction of the offspring will be homozygous recessive for both traits?

Accepted Answer

$\frac{1}{16}$

Question 19

Which process is responsible for the random distribution of maternal and paternal chromosomes into gametes?

Accepted Answer

Independent assortment

Question 20

A geneticist observes a karyotype with a deletion on chromosome 5. Which syndrome is most likely present?

Accepted Answer

Cri-du-chat Syndrome

Fundamentals of Genetics: Key Concepts, Processes, and Applications

Study Guide - Practice Questions