Biology (Cell Cycle)

Question 1

• The series of events that occurs in a cell from one division to the next.
• Cell cycle helps our body to grow and induce healing.

Answer 1

CELL CYCLE

Question 2

The cycle is divided into:

Answer 2

1. Interphase (G1, S, and G2)
2. Mitosis (Prophase, Metaphase, Anaphase, and Telophase)

Question 3

The length of the cycle is approximately

Answer 3

20 to 24 hours

Question 4

The interphase (preparation for mitosis) may last for about

Answer 4

18 to 20 hours

Question 5

The mitosis (cell division) may last for

Answer 5

2 hours

Question 6

(The cell prepares for the mitosis)

Answer 6

INTERPHASE

Question 7

• Cell increase in size and organelles duplicate.
• Production of carbohydrates, lipids, proteins, and enzymes in preparation for the next phases.

Answer 7

G1 PHASE (Gap 1)

Question 8

G1 Checkpoint Requirements

Answer 8

(1) Cell has enough nutrients like
protein, carbohydrates and lipids;
(2) Cell has adequate energy reserves; and
(3) Cell also checks for DNA damage.

Question 9

a surveillance mechanism that monitors the order, integrity, and fidelity of the major events of the cell cycle.

Answer 9

Checkpoint

Question 10

TRUE or FALSE: if some requirements are missing, the process will undergo cell cycle arrest or the cell cycle will stop; afterwards, the cell will activate programmed cell death or apoptosis.

Answer 10

TRUE

Question 11

• DNA that will be passed on the daughter cells in Mitotic phase is replicated.
• DNA replication (DNA can’t be too much or too less)

Answer 11

S PHASE (Synthesis of DNA)

Question 12

• Cell continues to increase in size and volume
• Replenishment of energy
• Microtubule assembles to form spindle fibers.

Answer 12

G2 PHASE (Gap 2)

Question 13

G2 Checkpoint Requirements

Answer 13

(1) Ensures that all DNA are completely
and correctly replicated;
(2) Repairing damages DNA; and
(3) Check if there if size and nutrients are sufficient.

Question 14

(This is the cell division proper)

Answer 14

THE MITOSIS (MITOTIC PHASE)

Question 15

• DNA condenses into chromosomes (DNA is doubled so there’s not much space in nucleus so it condenses to chromosomes)
• Centrosomes start to move to the opposite poles. - Spindle fibers emerge from the centrioles.
• Nuclear membrane and nucleolus disappear.

Answer 15

PROPHASE (pro-before; phase-appearance)

Question 16

• Centrioles have reached the opposite poles - Spindle is fully developed.
• Each chromosome (composed of 2 sister chromatids, attached by centromere, kinetochore is where spindle fibers attach to catch chromosomes) is attached to spindle fibers.
• Chromosomes align at the center.

Answer 16

METAPHASE (meta-middle; phase-appearance)

Question 17

M Checkpoint Requirements

Answer 17

Ensures that all of the chromosomes are attached to the spindle fibers by their kinetochore.

Question 18

TRUE OR FALSE: If there is an unattached chromosome, there will be abnormal cells.

Answer 18

TRUE

Question 19

• Sister chromatids are pulled toward opposite directions.
• Cells become elongated.

Answer 19

ANAPHASE (ana-backward; phase-appearance)

Question 20

• Chromosomes have reached their opposite poles.
• Formation of “cleavage furrow” (break between two cells)
• Nuclear membrane re-forms enclosing each set of chromosomes.
• Chromosomes start to decondense.
• The spindle fibers start to disappear.
• CYTOKINESIS (Cytoplasm divides into two new daughter cells and completely parts away)

Answer 20

TELOPHASE (telo-end; phase-appearance)

Question 21

(break between two cells)

Answer 21

cleavage furrow

Question 22

(Cytoplasm divides into two new daughter cells and completely parts away)

Answer 22

Cytokinesis

Question 23

The cell will undergo a “resting stage” before starting another cell cycle.

Answer 23

G0 PHASE

Question 24

• are condensed units of DNA
• sister chromatid (some have 1 or 2)
• connected by centromere (protein)
• kinetochore

Answer 24

Chromosomes

Question 25

• is composed of two centrioles.
• Emerge spindle fibers
• Composed of cytoskeleton
• Spindle fibers emerge from the centrosome during cell division.

Answer 25

Centrosome