BIOL180 Lesson 4 Quiz Cell Division
and Genetics Questions And Correct
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Rationales 2026 Q&A | Instant
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1. Which statement best describes the primary purpose of mitosis in a
multicellular organism?
A. To produce genetically different gametes
B. To reduce the chromosome number by half
C. To produce genetically similar daughter cells for growth and repair
D. To increase genetic variation through crossing over
Answer: C. To produce genetically similar daughter cells for growth
and repair
Rationale: Mitosis produces daughter cells that generally contain the
same chromosome number and essentially the same genetic
information as the parent cell. This process is essential for growth,
tissue maintenance, replacement of damaged cells, and asexual
reproduction in some organisms. In contrast, meiosis produces haploid
gametes and contributes substantially to genetic variation.
2. During which stage of the cell cycle is DNA replicated?
A. S phase
B. G1 phase
C. G2 phase
D. M phase
,Answer: A. S phase
Rationale: DNA replication occurs during the synthesis, or S, phase of
interphase. During this period, each chromosome is copied so that it
consists of two sister chromatids joined at a centromere. G1 primarily
involves growth and normal cellular activity, G2 prepares the cell for
division, and M phase encompasses mitosis and cytokinesis.
3. What is the correct sequence of the major stages of the cell cycle?
A. S, G1, M, G2
B. G1, S, G2, M
C. G2, G1, S, M
D. M, S, G1, G2
Answer: B. G1, S, G2, M
Rationale: The cell cycle is commonly organized into G1, S, G2, and M
phases. G1 is a growth and preparation period, S is when DNA is
replicated, G2 provides additional preparation for division, and M
includes mitosis and cytokinesis. Cells may also enter G0, a
nondividing state, from G1.
4. What is the main event of cytokinesis?
A. DNA replication
B. Chromosome condensation
C. Formation of homologous chromosome pairs
D. Division of the cytoplasm into daughter cells
Answer: D. Division of the cytoplasm into daughter cells
Rationale: Cytokinesis is the physical division of the cytoplasm,
producing separate daughter cells after nuclear division. In animal
cells, a cleavage furrow constricts the plasma membrane. In plant
,cells, vesicles form a cell plate that develops into a new cell wall.
Cytokinesis is distinct from mitosis, which divides the nucleus.
5. Which structure attaches sister chromatids to the spindle during
mitosis?
A. Ribosome
B. Kinetochore
C. Nucleolus
D. Lysosome
Answer: B. Kinetochore
Rationale: The kinetochore is a protein structure assembled at the
centromere of each chromosome. Spindle microtubules attach to
kinetochores and help move chromosomes during cell division.
Ribosomes synthesize proteins, lysosomes participate in intracellular
digestion, and the nucleolus produces ribosomal components.
6. During which stage of mitosis do chromosomes align at the cell's
equatorial plane?
A. Prophase
B. Telophase
C. Metaphase
D. Anaphase
Answer: C. Metaphase
Rationale: During metaphase, duplicated chromosomes line up near
the middle of the cell at the metaphase plate. Proper alignment helps
ensure that each daughter cell receives an appropriate set of
chromosomes. In anaphase, sister chromatids separate and move
toward opposite poles.
7. What happens to sister chromatids during anaphase of mitosis?
, A. They separate and move toward opposite poles
B. They pair with homologous chromosomes
C. They replicate their DNA
D. They undergo crossing over
Answer: A. They separate and move toward opposite poles
Rationale: Anaphase of mitosis begins when sister chromatids separate
at their centromeres. Once separated, each chromatid is considered an
individual chromosome and is pulled toward an opposite pole of the
cell. DNA replication occurs earlier during S phase, while crossing
over is associated with meiosis I.
8. Which checkpoint determines whether a cell has sufficient
resources and appropriate conditions to proceed toward DNA
replication?
A. G2 checkpoint
B. Spindle checkpoint
C. M checkpoint
D. G1 checkpoint
Answer: D. G1 checkpoint
Rationale: The G1 checkpoint evaluates factors such as cell size,
nutrients, growth signals, and DNA integrity before the cell commits to
DNA replication. Cells that do not receive appropriate signals may
enter G0. The G2 checkpoint evaluates replicated DNA and readiness
for mitosis, while the spindle checkpoint monitors chromosome
attachment during mitosis.
9. What is a major function of cyclins in the cell cycle?
A. They digest chromosomes
B. They regulate the activity of cyclin-dependent kinases
and Genetics Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
Download Pdf
1. Which statement best describes the primary purpose of mitosis in a
multicellular organism?
A. To produce genetically different gametes
B. To reduce the chromosome number by half
C. To produce genetically similar daughter cells for growth and repair
D. To increase genetic variation through crossing over
Answer: C. To produce genetically similar daughter cells for growth
and repair
Rationale: Mitosis produces daughter cells that generally contain the
same chromosome number and essentially the same genetic
information as the parent cell. This process is essential for growth,
tissue maintenance, replacement of damaged cells, and asexual
reproduction in some organisms. In contrast, meiosis produces haploid
gametes and contributes substantially to genetic variation.
2. During which stage of the cell cycle is DNA replicated?
A. S phase
B. G1 phase
C. G2 phase
D. M phase
,Answer: A. S phase
Rationale: DNA replication occurs during the synthesis, or S, phase of
interphase. During this period, each chromosome is copied so that it
consists of two sister chromatids joined at a centromere. G1 primarily
involves growth and normal cellular activity, G2 prepares the cell for
division, and M phase encompasses mitosis and cytokinesis.
3. What is the correct sequence of the major stages of the cell cycle?
A. S, G1, M, G2
B. G1, S, G2, M
C. G2, G1, S, M
D. M, S, G1, G2
Answer: B. G1, S, G2, M
Rationale: The cell cycle is commonly organized into G1, S, G2, and M
phases. G1 is a growth and preparation period, S is when DNA is
replicated, G2 provides additional preparation for division, and M
includes mitosis and cytokinesis. Cells may also enter G0, a
nondividing state, from G1.
4. What is the main event of cytokinesis?
A. DNA replication
B. Chromosome condensation
C. Formation of homologous chromosome pairs
D. Division of the cytoplasm into daughter cells
Answer: D. Division of the cytoplasm into daughter cells
Rationale: Cytokinesis is the physical division of the cytoplasm,
producing separate daughter cells after nuclear division. In animal
cells, a cleavage furrow constricts the plasma membrane. In plant
,cells, vesicles form a cell plate that develops into a new cell wall.
Cytokinesis is distinct from mitosis, which divides the nucleus.
5. Which structure attaches sister chromatids to the spindle during
mitosis?
A. Ribosome
B. Kinetochore
C. Nucleolus
D. Lysosome
Answer: B. Kinetochore
Rationale: The kinetochore is a protein structure assembled at the
centromere of each chromosome. Spindle microtubules attach to
kinetochores and help move chromosomes during cell division.
Ribosomes synthesize proteins, lysosomes participate in intracellular
digestion, and the nucleolus produces ribosomal components.
6. During which stage of mitosis do chromosomes align at the cell's
equatorial plane?
A. Prophase
B. Telophase
C. Metaphase
D. Anaphase
Answer: C. Metaphase
Rationale: During metaphase, duplicated chromosomes line up near
the middle of the cell at the metaphase plate. Proper alignment helps
ensure that each daughter cell receives an appropriate set of
chromosomes. In anaphase, sister chromatids separate and move
toward opposite poles.
7. What happens to sister chromatids during anaphase of mitosis?
, A. They separate and move toward opposite poles
B. They pair with homologous chromosomes
C. They replicate their DNA
D. They undergo crossing over
Answer: A. They separate and move toward opposite poles
Rationale: Anaphase of mitosis begins when sister chromatids separate
at their centromeres. Once separated, each chromatid is considered an
individual chromosome and is pulled toward an opposite pole of the
cell. DNA replication occurs earlier during S phase, while crossing
over is associated with meiosis I.
8. Which checkpoint determines whether a cell has sufficient
resources and appropriate conditions to proceed toward DNA
replication?
A. G2 checkpoint
B. Spindle checkpoint
C. M checkpoint
D. G1 checkpoint
Answer: D. G1 checkpoint
Rationale: The G1 checkpoint evaluates factors such as cell size,
nutrients, growth signals, and DNA integrity before the cell commits to
DNA replication. Cells that do not receive appropriate signals may
enter G0. The G2 checkpoint evaluates replicated DNA and readiness
for mitosis, while the spindle checkpoint monitors chromosome
attachment during mitosis.
9. What is a major function of cyclins in the cell cycle?
A. They digest chromosomes
B. They regulate the activity of cyclin-dependent kinases
