Cell Division [Mitosis]

Question 1

What is the main purpose of mitosis?

Answer 1

Growth & Repair

Question 2

What can mitosis produce from a single parent cell?

Answer 2

Two genetically identical daughter cells (single haploid cell (n) or diploid cell (2n) divides into two haploid or diploid daughter cells that are same as parent.)

Question 3

In what type of cells does mitosis occur? What does it mean?

Answer 3

Somatic cells, meaning all cells in the body except for the reproductive cells

Question 4

Is there a reduction in the number of chromosomes during mitosis?

Answer 4

No

Question 5

Why is mitosis important?

Answer 5

• Growth & development of multicellular organisms
• Repair & maintenance of damaged tissues (cut/injury)
• Asexual Reproduction of some organisms

Question 6

What happens during G1 Phase in mitosis interphase?

Answer 6

• Cell size doubles due to active metabolic activity
• Replication of organelles

Question 7

What happens during S-Phase in mitosis interphase?

Answer 7

• DNA replication

Question 8

What happens during G2 Phase in mitosis interphase?

Answer 8

• Enzymes for cell division are produced

Question 9

What are the 4 main phases of mitosis?

Answer 9

PMAT: Prophase, Metaphase, Anaphase, Telophase

Question 10

What happens during mitosis prophase?

Answer 10

• Chromosomes condenses (2 sister chromatids, held together at the centromere)
• Mitotic spindle begins to form from the centrioles as cytoskeleton disassemble
• centrioles migrate to opposite poles
• Nucleolus breaks down
• Chromosomes kinetochore attach to microtubules from each pole

Question 11

What happens in mitosis metaphase?

Answer 11

• All chromosomes align at the metaphase plate (center of the nucleus)

Question 12

What happens in mitosis anaphase?

Answer 12

• The chromosomes break apart
• Sister chromatids move to the opposite ends of the cell
• Microtubules not attached will elongate and push apart, separating the poles and making the cell longer.

Question 13

What happens in mitosis telophase?

Answer 13

• Cleavage furrow develops, made from contractile ring
• Chromosomes decondense and return to their ‘stringy’ form
• Two new nuclei forms
• Nuclear membranes and nucleoli reappear.
• Spindle apparatus breaks down to its building blocks

Question 14

What happens to plant cells in mitosis telophase?

Answer 14

• Vesicles form an expanding membrane partition (cell plate)

Question 15

What happens in mitosis cytokinesis?

Answer 15

• Division of cytoplasm

Question 16

What is the shortest phase?

Answer 16

Metaphase

Question 17

Why are checkpoints established during the cell cycle?

Answer 17

• Ensures the process is occurring accurately
• Prevents unregulated cell division, causes cancer (forms a lump)

Question 18

Where are the cell division checkpoints located and what are their main function?

Answer 18

1. G1/S Checkpoint - tells whether cell cycle continues or stops
2. G2/M Checkpoint - allows mitosis
3. Spindle Checkpoint - ensures that all chromosomes have attached to a spindle

Question 19

What are the contributing factors in cell cycle?

Answer 19

• Growth factors
• Size of cell
• Nutritional state of cell

Question 20

How long does mitosis typically take?

Answer 20

24 hours

Question 21

What happens to cells that do not divide?

Answer 21

1. Die
2. Take a specialized role (brain neuron)