Cell Cycle

Question 1

It is an active phase where the cell performs normal biochemical functions and prepares for division.

Answer 1

Interphase

Question 2

A phase in the interphase where the Cell grows and synthesizes proteins, lipids,
and carbohydrates.

Answer 2

G1 phase (Gap 1)

Question 3

A phase in the interphase where DNA replication occurs, forming two
copies of each chromosome.

Answer 3

S phase (Synthesis)

Question 4

A phase in the interphase where additional proteins and membranes are synthesized for cell division.

Answer 4

G2 phase (Gap 2):

Question 5

During which cell cycle phase does a cell exit the cycle from G1, maintain its specialized functions without dividing, and have the potential to re-enter the cycle, undergo mitosis, or undergo apoptosis if DNA damage is severe?

Answer 5

Interphase Gap 0 (quiescent phase)

Question 6

Which phase in the interphase occurs after mitosis, where the cell resumes synthesis of essential macromolecules, prepares plasma membrane components for future daughter cells and has a duration that varies by cell type?

Answer 6

G1 phase (Gap 1)

Question 7

What is the duration variety of cell types?

Answer 7

Duration varies by cell type:
○ Slow-dividing cells (e.g., liver cells) may enter G0 and remain there for years.
○ Fast-dividing cells (e.g., bone marrow cells) complete G1 in 16–24 hours.
○ Embryonic cells may skip G1 entirely.

Question 8

During which phase of the cell cycle in the interphase does DNA replication occur, producing two identical copies of each chromosome joined at the centromere?

Answer 8

S phase

Question 9

In which phase in the interphase are proteins needed for mitosis, like the mitotic spindle, synthesized, and microtubules form centrioles near the nucleus?

Answer 9

S phase

Question 10

During which phase in the interphase do centrioles and associated proteins form centrosomes that help organize the mitotic spindle, and mutations in centrosome-related genes can cause microcephaly?

Answer 10

S phase

Question 11

In which phase of the cell cycle does DNA replication occur, but the cell prepares for mitosis by synthesizing more proteins?

Answer 11

G2 phase

Question 12

During which phase in the interphase are plasma membrane components made in G1 stored in vesicles, which later merge with the plasma membrane to enclose daughter cells?

Answer 12

G2 Phase

Question 13

This is the process where a
replicated cell divides into two identical
daughter cells.

Answer 13

Mitosis

Question 14

They are the two identical strands of a replicated chromosome.

Answer 14

Chromatids

Question 15

The _________ of a replicated
chromosome splits, allowing chromatids
to separate into individual
chromosomes.

Answer 15

centromere

Question 16

In which phase of the cell cycle do chromosomes coil tightly, shortening and thickening?

Answer 16

Prophase

Question 17

During which phase do spindle fibers form from tubulin in the cytoplasm?

Answer 17

Prophase

Question 18

In which phase does the nuclear membrane break down and the nucleolus disappear?

Answer 18

Prophase

Question 19

In which phase of the cell cycle do chromosomes align at the cell’s center (equator)?

Answer 19

Metaphase

Question 20

During which phase do chromosomes attach to the spindle fibers at their centromeres?

Answer 20

Metaphase

Question 21

In which phase do chromosomes appear still but are under equal tension from both sides?

Answer 21

Metaphase

Question 22

In which phase of the cell cycle does the plasma membrane indent at the center?

Answer 22

Anaphase

Question 23

During which phase do centromeres split, allowing chromatids to separate and move to opposite sides?

Answer 23

Anaphase

Question 24

In which phase does the cell momentarily have twice the normal number of chromosomes?

Answer 24

Anaphase

Question 25

During which phase do microtubules stretch the dividing cell?

Answer 25

Anaphase

Question 26

In which phase of the cell cycle does the cell resemble a dumbbell with a set of chromosomes at each end?

Answer 26

Telophase

Question 27

During which phase does the spindle disassemble?

Answer 27

Telophase

Question 28

In which phase do nucleoli and nuclear membranes re-form?

Answer 28

Telophase

Question 29

During which phase is genetic division complete?

Answer 29

Telophase

Question 30

In which process are organelles and macromolecules distributed between two daughter cells?

Answer 30

Cytokinesis

Question 31

During which process does a microfilament band contract like a drawstring, fully separating the new cells?

Answer 31

Cytokinesis

Question 32

What happens when there is too little mitosis in the body and what happens if there is too much mitosis in the body?

Answer 32

Too little mitosis → Injuries remain unhealed. Too much mitosis → Abnormal growth (e.g., tumors).

Question 33

It ensures accurate chromosome replication and division:

Answer 33

Checkpoints

Question 34

Pauses the cycle to repair damaged DNA.

Answer 34

DNA Damage Checkpoint

Question 35

Ensures mitosis occurs instead of cell death.

Answer 35

Apoptosis Checkpoint

Question 36

Ensures proper spindle construction and chromosome attachment.

Answer 36

Spindle Assembly Checkpoint

Question 37

Cells follow an _________ that limits the number of divisions.

Answer 37

Internal Clock

Question 38

TRUE OR FALSE: Most mammalian cells divide 40–60 times before stopping.

Answer 38

TRUE

Question 39

What structures at the tips of chromosomes shorten with each cell division?

Answer 39

Telomeres

Question 40

It maintains telomere length in certain cells.

Answer 40

Telomerase enzymes

Question 41

signal aging and limit a cell’s lifespan.

Answer 41

Shortened telomeres

Question 42

TRUE OR FALSE: Environmental factors (stress, obesity, high blood sugar) accelerate telomere shortening.

Answer 42

TRUE

Question 43

TRUE OR FALSE: Exercise may slow telomere shortening, as seen in studies on identical twins.

Answer 43

TRUE

Question 44

– Cells stop dividing when they form a one-cell-thick layer. ○ If a gap forms, nearby cells divide to fill it, then stop.

Answer 44

Contact Inhibition

Question 45

Travel through the bloodstream to stimulate mitosis (e.g., uterine lining growth).

Answer 45

Hormones

Question 46

Act locally to promote mitosis (e.g., Epidermal Growth Factor aids wound healing).

Answer 46

Growth factors

Question 47

TRUE OR FALSE: Some cancer drugs block growth factor receptors to stop abnormal cell division.

Answer 47

TRUE

Question 48

TRUE OR FALSE: Cyclins & kinases regulate mitosis by turning on necessary genes.

Answer 48

TRUE

Question 49

Which of the following is true about cyclins and kinases? A) Cyclin levels remain constant, while kinase levels fluctuate. B) Cyclin levels fluctuate, while kinase levels remain constant. C) Both cyclin and kinase levels fluctuate equally.

Answer 49

B) Cyclin levels fluctuate, while kinase levels remain constant.

Question 50

Which of the following is true about cyclin-kinase pairs and mitosis? A) When enough cyclin-kinase pairs accumulate, mitosis begins. B) Mitosis begins when cyclin levels remain constant. C) Mitosis begins when kinase levels fluctuate.

Answer 50

A) When enough cyclin-kinase pairs accumulate, mitosis begins.

Question 51

Which of the following is true about cyclin degradation and resetting the cycle? A) Enzymes degrade cyclins once mitosis starts, resetting the cycle for the next division. B) Cyclins degrade enzymes once mitosis starts, resetting the cycle for the next division. C) Cyclins remain intact after mitosis and do not affect the cycle.

Answer 51

A) Enzymes degrade cyclins once mitosis starts, resetting the cycle for the next division.