Question 1

Which of the following best describes the main purpose of the G1 phase in the eukaryotic cell cycle?

Accepted Answer

Recovery from previous division, organelle increase, and accumulation of materials for DNA synthesis

Question 2

During which phase of the cell cycle does DNA replication occur, and what is the result for each chromosome?

Accepted Answer

S phase; each chromosome consists of two identical sister chromatids

Question 3

A scientist observes a cell with chromosomes lined up at the center of the cell, attached to spindle fibers. Which stage of mitosis is this cell in?

Accepted Answer

Metaphase

Question 4

Which checkpoint in the cell cycle is responsible for ensuring that all chromosomes are properly aligned before separation?

Accepted Answer

M checkpoint

Question 5

If a human cell fails to repair DNA damage detected at the G1 checkpoint, what is the most likely outcome?

Accepted Answer

The cell will undergo apoptosis (programmed cell death)

Question 6

Which of the following statements about diploid and haploid numbers in humans is correct?

Accepted Answer

The diploid number ($$2n) is 46 $$and the haploid number ($$n) is 23$$

Question 7

Which of the following best explains why nerve and muscle cells typically remain in the G0 phase?

Accepted Answer

They do not need to divide and instead grow larger without producing new cells

Question 8

What is the primary function of mitosis in multicellular organisms such as humans and plants?

Accepted Answer

Growth, development, and repair of tissues

Question 9

Which of the following events occurs during prophase of mitosis?

Accepted Answer

Nuclear envelope fragments and spindle fibers begin to assemble

Question 10

A mutation causes a cell to skip the M checkpoint. What is a likely consequence of this mutation?

Accepted Answer

Chromosomes may not be properly distributed, leading to daughter cells with abnormal chromosome numbers

Question 11

Which of the following best describes the structure of chromatin in eukaryotic cells?

Accepted Answer

DNA double helix wound around histone proteins, forming nucleosomes

Question 12

In which stage of mitosis do the centromeres dissolve and sister chromatids become daughter chromosomes?

Accepted Answer

Anaphase

Question 13

Which of the following is a key difference between mitosis in eukaryotes and binary fission in prokaryotes?

Accepted Answer

Mitosis involves division of a nucleus, while binary fission does not

Question 14

A researcher is studying a plant cell in telophase. Which of the following would she most likely observe?

Accepted Answer

A new nuclear envelope is forming around the daughter chromosomes

Question 15

Which of the following best describes the role of cyclins in the cell cycle?

Accepted Answer

They are internal proteins whose concentration fluctuates to regulate progression through cell cycle checkpoints

Question 16

A cell with 32 chromosomes undergoes mitosis. How many chromosomes will each daughter cell have after cytokinesis?

Accepted Answer

$$32$$

Question 17

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

Accepted Answer

Production of gametes

Question 18

During which stage of the cell cycle are organelles duplicated to ensure each daughter cell receives a full set?

Accepted Answer

G1 phase

Question 19

Which of the following best explains why apoptosis is important in the cell cycle?

Accepted Answer

It eliminates cells with damaged DNA, preventing the propagation of errors

Question 20

A bacterial cell divides every 20 minutes by binary fission. If you start with one cell, how many cells will there be after 1 hour?

Accepted Answer

$$8$$

The Cell Cycle and Cellular Division: Mitosis and Binary Fission

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