Question 1

Which of the following best describes the difference between a somatic cell and a gamete in humans?

Accepted Answer

A somatic cell is diploid (2n = 46) and a gamete is haploid (n = 23).

Question 2

Which event occurs during meiosis I but not during mitosis?

Accepted Answer

Formation of tetrads and crossing over

Question 3

If an African clawed frog has 36 chromosomes in its somatic cells, what is its haploid number?

Accepted Answer

$$n = 18$$

Question 4

Which mechanism is responsible for producing recombinant chromosomes during meiosis?

Accepted Answer

Crossing over

Question 5

How many possible combinations of chromosomes can be produced in human gametes by independent assortment alone?

Accepted Answer

$$2^{23}$$

Question 6

Which statement about homologous chromosomes is correct?

Accepted Answer

They carry genes controlling the same inherited characters at the same loci.

Question 7

What is the primary evolutionary significance of genetic variation within populations?

Accepted Answer

It allows populations to accumulate genetic variations favored by the environment through natural selection.

Question 8

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

Accepted Answer

Replication of DNA during mitosis

Question 9

During which phase of meiosis do homologous chromosomes physically connect and exchange genetic information?

Accepted Answer

Prophase I

Question 10

A zygote is formed by the union of two gametes. What is the chromosome number of a human zygote?

Accepted Answer

$$2n = 46$$

Question 11

Which of the following best explains why sexual reproduction is common in multicellular organisms?

Accepted Answer

It increases genetic variation, which can enhance adaptability to changing environments.

Question 12

Which term refers to the specific location of a gene on a chromosome?

Accepted Answer

Locus

Question 13

Which process results in four haploid daughter cells, each with unreplicated chromosomes?

Accepted Answer

Meiosis II

Question 14

What is the role of codons in the genetic code?

Accepted Answer

They are triplet nucleotides in mRNA that encode for specific amino acids.

Question 15

Which of the following is true about autosomes in humans?

Accepted Answer

There are 22 pairs of autosomes in human cells.

Question 16

Which equation correctly represents the number of possible diploid combinations produced by random fertilization in humans?

Accepted Answer

$$(2^{23})^2$

Question 17

Which statement best describes the outcome of crossing over during meiosis?

Accepted Answer

It increases genetic variation by combining DNA from two parents into a single chromosome.

Question 18

Which phase of meiosis is referred to as the reductional division?

Accepted Answer

Meiosis I

Question 19

Which of the following is a direct result of mutations in DNA?

Accepted Answer

Creation of different versions of genes called alleles

Question 20

Which of the following best describes the unity of living things at the genetic level?

Accepted Answer

All life has a common origin, and genes with similar functions in different organisms are similar in structure and DNA sequence.

Principles of Genetics: Meiosis, Inheritance, and Genetic Variation

Study Guide - Practice Questions