Cell Cycle

Question 1

Which of the following correctly describes the S phase of the cell cycle?
A) The cell carries out regular activities and grows
B) DNA inside the nucleus replicates, creating a copy of each chromosome
C) The cell prepares for mitosis and cytokinesis
D) The cytoplasm divides to form two new daughter cells

Answer 1

Answer: B

Question 2

What happens during G1 of interphase?

Answer 2

Regular cell activity and cell growth occur.

Question 3

During which phase of mitosis do chromosomes align at the cell’s equator?
A) Prophase
B) Metaphase
C) Anaphase
D) Telophase

Answer 3

B) Metaphase

Question 4

What is the purpose of cytokinesis?

Answer 4

To divide the cytoplasm and create two new daughter cells after mitosis.

Question 5

5. Multiple Choice:

Which of the following structures helps separate sister chromatids during anaphase?
A) Centromeres
B) Nuclear membranes
C) Golgi vesicles
D) Mitotic spindle fibers

Answer 5

D) Mitotic spindle fibers

Question 6

6. Short Answer:

How does cytokinesis differ between plant and animal cells?

Answer 6

In animal cells, a cleavage furrow pinches the cell in two.
In plant cells, a cell plate forms from a phragmoplast and grows outward to become a new cell wall.

Question 7

Which phase of mitosis is characterized by the breakdown of the nuclear membrane and the condensation of DNA?
A) Prophase
B) Metaphase
C) Anaphase
D) Telophase

Answer 7

A) Prophase

Question 8

What are sister chromatids?

Answer 8

Each identical copy of a single chromosome.

Question 9

What is the correct order of mitosis?
A) Metaphase → Prophase → Anaphase → Telophase
B) Prophase → Anaphase → Telophase → Metaphase
C) Anaphase → Prophase → Telophase → Metaphase
D) Prophase → Metaphase → Anaphase → Telophase

Answer 9

D) Prophase → Metaphase → Anaphase → Telophase

Question 10

What structure forms the spindle fibers that help move chromosomes during mitosis?

Answer 10

Microtubules growing from centrioles.

Question 11

What happens during G2 of interphase?
A) The cell carries out normal activities and grows
B) The DNA inside the nucleus replicates
C) The cell continues to prepare for mitosis and cytokinesis
D) The nuclear membrane breaks down

Answer 11

✅ Answer: C

Question 12

What happens to the DNA during prophase?

Answer 12

➡️ The DNA condenses (becoming shorter and thicker), making the chromosomes visible.

Question 13

What structure do spindle fibers grow from during mitosis?
A) Kinetochores
B) Centrioles
C) Golgi apparatus
D) Nucleus

Answer 13

✅ Answer: B

Question 14

What happens to spindle fibers during telophase?

Answer 14

➡️ The spindle fibers disappear.

Question 15

What do kinetochores do during anaphase?
A) Help chromosomes line up at the equator
B) Pull chromatids toward opposite poles by connecting to spindle fibers
C) Form the cleavage furrow in animal cells
D) Assist in nuclear membrane breakdown

Answer 15

✅ Answer: B

Question 16

What happens to chromosomes at the end of telophase?

Answer 16

➡️ The chromosomes uncoil.

Question 17

Which organelle helps form the cell plate during plant cytokinesis?
A) Ribosomes
B) Golgi apparatus
C) Centrioles
D) Mitochondria

Answer 17

✅ Answer: B

Question 18

What is a phragmoplast, and what is its function?

Answer 18

➡️ A phragmoplast is an assembly of microtubules and vesicles from the Golgi apparatus that helps form the cell plate in plant cytokinesis.

Question 19

During metaphase, what happens to the mitotic spindle?
A) It begins forming and growing out of centrioles
B) It disappears as chromosomes move to opposite poles
C) It fully forms and connects to each chromosome pair
D) It helps the nuclear membrane reform

Answer 19

✅ Answer: C

Question 20

What is the role of the cleavage furrow in animal cell cytokinesis?

Answer 20

➡️ The cleavage furrow forms at the center of the cell, pinching through and dividing the cell into two daughter cells.

Question 21

How does the cell plate grow in plant cytokinesis?
A) From the outside-in
B) From the inside-out
C) It forms instantly in one step
D) It does not grow; the cell just pinches apart

Answer 21

✅ Answer: B

Question 22

List the stages of mitosis in the proper order.

Answer 22

Prophase –> metaphase –> anaphase –> telophase –> cytokinesis.

Question 23

The purpose of mitosis is
a) Cell Division
b) Cell Growth
c) DNA Replication
d) Manufacturing of Mitochondria
e) An illness of the liver

Answer 23

a) Cell Division

Question 24

Describe the following parts of a chromosome.

Chromosome

SIster chomotid

Centronmere

Telomeres

Answer 24

Chromosome: The entire Chromosome structure, a combination of two sister chomotids, a centromere and a pair of telomere at the top/bottom ends of the structure.

Sister Chromotid: One of the duplicated halfs of the chromosome structure, looks like half of an “X”

Centromere: A centromere is a constricted region of a chromosome that separates it into a short arm (top) and a long arm (bottom).

Telomere: The top/bottom ends of the sister chromatids. Protective structures made of DNA and proteins.

Question 25

What is a **Telomere**?

Answer 25

**Telomere**: The top/bottom ends of the sister chromatids. Protective structures made of DNA and proteins.

Question 26

What is a **Centromere**?

Answer 26

**Centromere**: A centromere is a constricted region of a chromosome that separates it into a short arm (top) and a long arm (bottom).

Question 27

What stage of mitosis is the following cell in? Justify your answer. (#1)

Answer 27

**Metaphase**: All the sister chromatids are lining up at the equator of the cell, and you can see the spindal fibers from the centromeres reaching for individual sister chromatids.

Question 28

What stage of mitosis is the following cell in? Justify your answer. (#3)

Answer 28

**Prophase**: The DNA seems like it has started condensing into sister chromatids because there are thicker and longer blobs of DNA mixed in with the smaller ones. This is different from the other cells nearby, which only have small blobs of DNA.

Question 29

What stage of mitosis is the following cell in? Justify your answer. (#2)

Answer 29

**Telophase**: The sister chromotids are clomped into two large blobs at the poles of cells and they look like they have some kind of nuclear membrane forming around the uncoiling sister chromotids because of the relatively smooth shape.

Question 30

What stage of mitosis is the following cell in? Justify your answer. (#4)

Answer 30

**Anaphase**: The sister chromotids look connected to spindle fibers, pulling them to opposite poles of the cell (based on the gap between the groups of sister chromotids).

Question 31

What is the difference between cytokinesis and telophase?

Answer 31

**Cytokinesis** is the division of cytoplasm and the pinching off of the cell membrane. **Telophase** includes the reformation of the nucleus and disappearance of the centrioles. DNA is still condensed in telophase, whereas in cytokinesis, it is loosely packed chromatin.

Question 32

What are the three main stages of the cell cycle? Which stage takes the longest time? Why does the cell remain in this stage the longest?

Answer 32

The stages: Interphase, Cell Division: Mitosis, and Cytokinesis On average, cells spend the most time in Interphase, growing and functioning. Many specialized cells remain in interphase their entire life.