Question 1

Which of the following best explains why cells are limited in size by the surface area-to-volume ratio?

Accepted Answer

As cells grow, their volume increases faster than their surface area, making it harder to exchange materials efficiently.

Question 2

During which phase of the cell cycle does DNA replication occur?

Accepted Answer

S phase

Question 3

A human somatic cell contains 46 chromosomes. After DNA replication but before mitosis, how many chromatids are present in the cell?

Accepted Answer

$$92$$

Question 4

Which of the following events distinguishes metaphase I of meiosis from metaphase of mitosis?

Accepted Answer

Homologous pairs of chromosomes line up at the metaphase plate.

Question 5

If a diploid organism has $$2n = 8$$ chromosomes, how many chromosomes will each gamete have after meiosis?

Accepted Answer

$$4$$

Question 6

Which process during meiosis is primarily responsible for generating new combinations of alleles on the same chromosome?

Accepted Answer

Crossing over (crossover)

Question 7

A cell fails to separate homologous chromosomes during meiosis I. What is the most likely result?

Accepted Answer

Some gametes will have an extra chromosome, and some will be missing one (aneuploidy).

Question 8

Which of the following best describes the difference between autosomes and sex chromosomes in humans?

Accepted Answer

Autosomes carry genes for various traits, while sex chromosomes determine biological sex.

Question 9

Which chromosomal mutation results in a chromosome segment being reversed end to end?

Accepted Answer

Inversion

Question 10

During which stage of mitosis do sister chromatids separate and move toward opposite poles?

Accepted Answer

Anaphase

Question 11

Which of the following is a direct consequence of crossing over during meiosis?

Accepted Answer

Increased genetic variation among gametes

Question 12

A cell with loosely coiled chromatin is most likely in which phase of the cell cycle?

Accepted Answer

Interphase

Question 13

Which of the following best describes the outcome of cytokinesis in animal cells?

Accepted Answer

The cytoplasm divides, resulting in two daughter cells.

Question 14

If a mutation occurs during meiosis that results in a chromosome segment being lost, what type of chromosomal mutation has occurred?

Accepted Answer

Deletion

Question 15

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

Accepted Answer

Homologous chromosomes pair up and undergo synapsis

Question 16

A human cell with 47 chromosomes is most likely the result of which meiotic error?

Accepted Answer

Nondisjunction

Question 17

Which of the following best explains why random fertilization increases genetic variation?

Accepted Answer

It allows any sperm to fertilize any egg, combining different genetic backgrounds.

Question 18

Which of the following statements about chromatin and chromosomes is correct?

Accepted Answer

Chromatin is loosely coiled DNA, while chromosomes are tightly coiled and visible during cell division.

Question 19

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

Accepted Answer

Replication of DNA during S phase

Question 20

A cell with two sets of chromosomes is described as:

Accepted Answer

Diploid

Cell Cycle, Mitosis, Meiosis, and Chromosomal Variation

Study Guide - Practice Questions