Question 1

Which of the following best describes the process of binary fission in prokaryotes?

Accepted Answer

It is a form of asexual reproduction where the cell divides in half, producing two genetically identical daughter cells.

Question 2

A researcher treats cells with a chemical that prevents DNA synthesis from starting. In which phase of the cell cycle would these cells be trapped?

Accepted Answer

G1 phase

Question 3

Which of the following events occurs during prophase I of meiosis but not during mitosis?

Accepted Answer

Pairing of homologous chromosomes and crossing over

Question 4

A human somatic cell contains 46 chromosomes. After mitosis and cytokinesis, how many chromosomes will each daughter cell contain?

Accepted Answer

$$46$$

Question 5

Which of the following best explains why cancer cells are able to divide uncontrollably?

Accepted Answer

They ignore cell cycle control signals and do not respond to growth factors.

Question 6

Which of the following is a direct result of nondisjunction during meiosis?

Accepted Answer

Production of gametes with abnormal numbers of chromosomes

Question 7

What is the main difference between cytokinesis in plant cells and animal cells?

Accepted Answer

Plant cells form a cell plate, while animal cells form a cleavage furrow.

Question 8

Which of the following best describes homologous chromosomes?

Accepted Answer

They carry genes for the same traits at the same loci, but may have different alleles.

Question 9

Which of the following equations correctly represents the possible chromosome combinations in human gametes due to independent assortment?

Accepted Answer

$$2^{23}$$

Question 10

A karyotype is useful for which of the following purposes?

Accepted Answer

Identifying chromosomal abnormalities such as extra or missing chromosomes

Question 11

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

Accepted Answer

Replication of DNA during S phase

Question 12

Which chromosomal abnormality causes Down syndrome?

Accepted Answer

Trisomy 21

Question 13

Which of the following best describes the difference between somatic cells and gametes in humans?

Accepted Answer

Somatic cells are diploid, while gametes are haploid.

Question 14

Which of the following is a multi-step process that leads to increased genetic diversity in offspring?

Accepted Answer

Crossing over during meiosis and random fertilization

Question 15

Which syndrome is characterized by the presence of a single X chromosome and no Y chromosome?

Accepted Answer

Turner syndrome

Question 16

Which of the following changes in chromosome structure can result from errors in meiosis or exposure to radiation?

Accepted Answer

Deletions, duplications, inversions, and translocations

Question 17

Which phase of the cell cycle is characterized by the preparation for cell division, with duplicated DNA still in chromatin form?

Accepted Answer

G2 phase

Question 18

Which of the following best describes a clone?

Accepted Answer

A genetically identical copy of an organism produced by asexual reproduction

Question 19

Which of the following drugs is used in cancer treatment because it prevents the formation of the mitotic spindle?

Accepted Answer

Vinblastin

Question 20

If a cell with 46 chromosomes undergoes meiosis, how many chromosomes will each resulting gamete contain?

Accepted Answer

$$23$$

The Cellular Basis of Reproduction and Inheritance: Cell Division, Chromosomes, and Genetic Variation

Study Guide - Practice Questions