Question 1

Which of the following best describes the difference between binary fission and mitosis?

Accepted Answer

Binary fission is a simpler process found in prokaryotes, while mitosis is a complex process involving multiple phases in eukaryotes.

Question 2

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

Accepted Answer

S phase

Question 3

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

Accepted Answer

46 chromosomes

Question 4

Which structure is responsible for holding sister chromatids together after DNA replication?

Accepted Answer

Cohesion proteins

Question 5

What is the primary function of the G$$_1/S $$checkpoint in the cell cycle?

Accepted Answer

To verify that the cell has reached adequate size and has sufficient resources for DNA replication

Question 6

Which of the following best explains why cancer can result from a failure in cell cycle control?

Accepted Answer

Cells proliferate uncontrollably due to mutations in proto-oncogenes and tumor-suppressor genes

Question 7

If a mutation causes a proto-oncogene to become overactive, what is the likely result?

Accepted Answer

The cell will receive constant signals to divide, potentially leading to cancer

Question 8

Which of the following equations correctly represents the chromosome number in a diploid human cell?

Accepted Answer

$$2n = 46$$

Question 9

During metaphase of mitosis, chromosomes align at the spindle equator. What is the significance of this arrangement?

Accepted Answer

It ensures that sister chromatids are evenly separated into two daughter cells.

Question 10

A researcher observes a cell with chromosomes attached to spindle fibers but not yet separated. Which stage of mitosis is this cell most likely in?

Accepted Answer

Metaphase

Question 11

Which of the following is a direct consequence of a loss-of-function mutation in a tumor-suppressor gene?

Accepted Answer

Cells lose the ability to detect problems and stop division, increasing cancer risk.

Question 12

Which of the following best describes the role of kinetochores during mitosis?

Accepted Answer

They bind microtubules to chromosomes, facilitating chromatid separation.

Question 13

A cell fails to pass the spindle checkpoint during mitosis. What is the most likely outcome?

Accepted Answer

The cell cycle will pause until all chromosomes are properly attached to spindle fibers.

Question 14

Which of the following is NOT a function of mitosis in multicellular organisms?

Accepted Answer

Sexual reproduction

Question 15

In a medical case, a patient’s cells are found to have both copies of a tumor-suppressor gene mutated. What is the most likely effect on the cell cycle?

Accepted Answer

The cell will lose its 'brake' and may divide uncontrollably.

Question 16

Which of the following best explains why HeLa cells are significant in research?

Accepted Answer

They are cancer cells that have been dividing continuously since 1951.

Question 17

Which phase of the cell cycle includes both G$$_1$$, S, and G$$_2$$ phases?

Accepted Answer

Interphase

Question 18

A cell with a karyotype showing 46 chromosomes, arranged in homologous pairs, is best described as:

Accepted Answer

Diploid

Question 19

Which of the following events occurs during cytokinesis in animal cells?

Accepted Answer

Constriction of the contractile ring composed of actin and myosin

Question 20

If a cell fails to replicate its DNA during S phase, which checkpoint is most likely to prevent it from entering mitosis?

Accepted Answer

G$$_2/M $$checkpoint

Cell Division: Mitosis and Chromosome Structure

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