BIOL180 Practice Exam 3 Cell
Division (Mitosis and Meiosis)
Questions And Correct Answers
(Verified Answers) Plus Rationales
2026 Q&A | Instant Download Pdf
1. What is the primary purpose of cell division in multicellular
organisms?
A. To prevent DNA replication
B. To eliminate all genetic variation
C. To produce new cells for growth, repair, and reproduction
D. To stop cellular metabolism
Answer: C. To produce new cells for growth, repair, and
reproduction
Rationale: Cell division allows multicellular organisms to increase in
size, replace damaged or worn-out cells, and, in some organisms,
reproduce. Mitosis generally produces genetically similar daughter
cells for growth and maintenance, whereas meiosis produces
specialized cells used in sexual reproduction.
2. Which process produces two genetically similar daughter cells
from one parent cell?
A. Mitosis
B. Meiosis
C. Crossing over
D. Fertilization
,Answer: A. Mitosis
Rationale: Mitosis is nuclear division that distributes duplicated
chromosomes so that each daughter nucleus receives an essentially
identical set of chromosomes. It is important for growth, tissue repair,
and asexual reproduction in many organisms.
3. During which part of the cell cycle is DNA replicated?
A. G1 phase
B. S phase
C. G2 phase
D. M phase
Answer: B. S phase
Rationale: The S, or synthesis, phase is the portion of interphase
during which DNA is replicated. After replication, each chromosome
consists of two sister chromatids joined at the centromere.
4. Which sequence correctly represents the major stages of the cell
cycle?
A. M → G2 → S → G1
B. S → G1 → M → G2
C. G2 → S → G1 → M
D. G1 → S → G2 → M
Answer: D. G1 → S → G2 → M
Rationale: The cell cycle proceeds through G1, S, G2, and M phases.
G1 involves growth and normal cellular activity, S involves DNA
replication, G2 prepares the cell for division, and M includes mitosis
and usually cytokinesis.
5. What happens during G1 phase?
,A. Homologous chromosomes pair
B. DNA is separated into daughter cells
C. The cell grows and performs normal metabolic functions
D. Sister chromatids separate
Answer: C. The cell grows and performs normal metabolic functions
Rationale: During G1, the cell grows, produces proteins and
organelles, and carries out its normal functions. DNA replication has
not yet occurred; that process takes place during S phase.
6. What is the main event of S phase?
A. DNA replication
B. Cytokinesis
C. Chromosome condensation
D. Homologous chromosome separation
Answer: A. DNA replication
Rationale: S phase is characterized by duplication of the cell's DNA.
Each chromosome is copied, producing two genetically identical sister
chromatids connected at the centromere.
7. Why is DNA replication necessary before mitosis?
A. It reduces chromosome number
B. It creates mutations in every chromosome
C. It allows homologous chromosomes to exchange DNA
D. It ensures that each daughter cell can receive a complete genome
Answer: D. It ensures that each daughter cell can receive a complete
genome
Rationale: A cell must duplicate its chromosomes before division so
that the replicated copies can be distributed to daughter cells. Without
, DNA replication, daughter cells would receive incomplete genetic
information.
8. Which structure holds sister chromatids together before they
separate?
A. Spindle fiber
B. Centromere region
C. Nucleolus
D. Cell wall
Answer: B. Centromere region
Rationale: Sister chromatids are connected at a chromosome region
called the centromere. Protein complexes associated with the
centromere help organize chromosome movement during cell division.
9. What is a chromosome composed primarily of?
A. Lipids and carbohydrates
B. RNA and lipids
C. DNA associated with proteins
D. ATP and enzymes
Answer: C. DNA associated with proteins
Rationale: Eukaryotic chromosomes consist primarily of DNA
packaged with proteins called histones and other chromosome-
associated proteins. This organization allows very long DNA molecules
to fit within the nucleus.
10. Which phase follows S phase during the standard cell cycle?
A. G2 phase
B. G1 phase
Division (Mitosis and Meiosis)
Questions And Correct Answers
(Verified Answers) Plus Rationales
2026 Q&A | Instant Download Pdf
1. What is the primary purpose of cell division in multicellular
organisms?
A. To prevent DNA replication
B. To eliminate all genetic variation
C. To produce new cells for growth, repair, and reproduction
D. To stop cellular metabolism
Answer: C. To produce new cells for growth, repair, and
reproduction
Rationale: Cell division allows multicellular organisms to increase in
size, replace damaged or worn-out cells, and, in some organisms,
reproduce. Mitosis generally produces genetically similar daughter
cells for growth and maintenance, whereas meiosis produces
specialized cells used in sexual reproduction.
2. Which process produces two genetically similar daughter cells
from one parent cell?
A. Mitosis
B. Meiosis
C. Crossing over
D. Fertilization
,Answer: A. Mitosis
Rationale: Mitosis is nuclear division that distributes duplicated
chromosomes so that each daughter nucleus receives an essentially
identical set of chromosomes. It is important for growth, tissue repair,
and asexual reproduction in many organisms.
3. During which part of the cell cycle is DNA replicated?
A. G1 phase
B. S phase
C. G2 phase
D. M phase
Answer: B. S phase
Rationale: The S, or synthesis, phase is the portion of interphase
during which DNA is replicated. After replication, each chromosome
consists of two sister chromatids joined at the centromere.
4. Which sequence correctly represents the major stages of the cell
cycle?
A. M → G2 → S → G1
B. S → G1 → M → G2
C. G2 → S → G1 → M
D. G1 → S → G2 → M
Answer: D. G1 → S → G2 → M
Rationale: The cell cycle proceeds through G1, S, G2, and M phases.
G1 involves growth and normal cellular activity, S involves DNA
replication, G2 prepares the cell for division, and M includes mitosis
and usually cytokinesis.
5. What happens during G1 phase?
,A. Homologous chromosomes pair
B. DNA is separated into daughter cells
C. The cell grows and performs normal metabolic functions
D. Sister chromatids separate
Answer: C. The cell grows and performs normal metabolic functions
Rationale: During G1, the cell grows, produces proteins and
organelles, and carries out its normal functions. DNA replication has
not yet occurred; that process takes place during S phase.
6. What is the main event of S phase?
A. DNA replication
B. Cytokinesis
C. Chromosome condensation
D. Homologous chromosome separation
Answer: A. DNA replication
Rationale: S phase is characterized by duplication of the cell's DNA.
Each chromosome is copied, producing two genetically identical sister
chromatids connected at the centromere.
7. Why is DNA replication necessary before mitosis?
A. It reduces chromosome number
B. It creates mutations in every chromosome
C. It allows homologous chromosomes to exchange DNA
D. It ensures that each daughter cell can receive a complete genome
Answer: D. It ensures that each daughter cell can receive a complete
genome
Rationale: A cell must duplicate its chromosomes before division so
that the replicated copies can be distributed to daughter cells. Without
, DNA replication, daughter cells would receive incomplete genetic
information.
8. Which structure holds sister chromatids together before they
separate?
A. Spindle fiber
B. Centromere region
C. Nucleolus
D. Cell wall
Answer: B. Centromere region
Rationale: Sister chromatids are connected at a chromosome region
called the centromere. Protein complexes associated with the
centromere help organize chromosome movement during cell division.
9. What is a chromosome composed primarily of?
A. Lipids and carbohydrates
B. RNA and lipids
C. DNA associated with proteins
D. ATP and enzymes
Answer: C. DNA associated with proteins
Rationale: Eukaryotic chromosomes consist primarily of DNA
packaged with proteins called histones and other chromosome-
associated proteins. This organization allows very long DNA molecules
to fit within the nucleus.
10. Which phase follows S phase during the standard cell cycle?
A. G2 phase
B. G1 phase
