Module 2 Section 6 - The Cell Cycle and Mitosis

Question 1

What is the cell cycle

Answer 1

The process that all body cells in multicellular organisms use to grow and divide

Question 2

When does the cell cycle start

Answer 2

When a cell has been produced by cell division

Question 3

When does the cell cycle end

Answer 3

It ends with the cell dividing to produce two identical cells

Question 4

What does the cell cycle consist of

Answer 4

Interphase (Cell growth and DNA replication)
M Phase (Mitosis and cytokinesis)

Question 5

Interphase is divided into 3 stages what are they

Answer 5

G1 (gap phase 1), S (synthesis), G2 (gap phase 2)

Question 6

What happens in gap phase 1

Answer 6

In gap phase 1 the cell grows and new organelles and proteins are made

Question 7

How is the cell cycle regulated

Answer 7

By checkpoints

Question 8

When do checkpoints occur

Answer 8

At key points during the cycle to make sure it’s ok for the process to continue

Question 9

What happens after g1

Answer 9

The cell undergoes checks at the g1 checkpoint

Question 10

What does the g1 checkpoint check for

Answer 10

Checks that the chemicals needed for replication are present and checks for damage to the DNA before enter S-phase

Question 11

After passing the g1 checkpoint what happens to a cell in the cell cycle

Answer 11

The cell enters synthesis phase

Question 12

What happens in the synthesis phase in the cell cycle

Answer 12

The cell replicates it’s DNA ready to divide by mitosis

Question 13

What happens to the cell after synthesis stage

Answer 13

It enters g2 (gap phase 2)

Question 14

What happens in g2

Answer 14

Cell keeps growing and proteins needed for cell division are made

Question 15

What happens after g2

Answer 15

The cell has to clear the g2 checkpoint

Question 16

What does the g2 checkpoint check for

Answer 16

The cell checks whether all the DNA has been replicated without any damage

Question 17

What happens after the cell clears the g2 checkpoint

Answer 17

It enters m-phase

Question 18

What happens in m-phase

Answer 18

The cell goes through mitosis and cytokinesis

Question 19

What happens to the cell after m-phase

Answer 19

It has to pass through the metaphase checkpoint

Question 20

Where does interphase start

Answer 20

G1

Question 21

Where does interphase end

Answer 21

G2 checkpoint

Question 22

How many stages does mitosis have

Answer 22

4 stages

Question 23

Why is mitosis needed

Answer 23

Mitosis is needed for growth of multicellular organisms and for repairing damaged tissues

Question 24

What are the stages of mitosis in order

Answer 24

Prophase
Metaphase
Anaphase
Telophase

Question 25

What happens before mitosis

Answer 25

Interphase

Question 26

What happens to the cell in interphase

Answer 26

The cell prepares for division The cell’s DNA will unravel and replicate to double its genetic content Organelles are replicated so it has spare ones ATP content is increased so it provides energy needed for cell division

Question 27

What happens to the cell in the prophase stage of mitosis

Answer 27

Chromosomes condense (get shorter and fatter) Centrioles move to opposite ends of the cell Network of protein fibres form, called the spindle Nuclear envelope breaks down, DNA lies free in cytoplasm

Question 28

What happens to the cell in the metaphase stage of mitosis

Answer 28

The chromosomes (each with 2 Chromatids) line up along the middle of the cell They attach to the spindle by their centromere

Question 29

What happens at the metaphase checkpoint

Answer 29

The cell checks that all the chromosomes are attached to the spindle before mitosis can continue

Question 30

What happens to the cell in the anaphase stage of mitosis

Answer 30

The centromere divide - each pair of sister chromatids are separated The spindles contract pulling chromatids to the opposite ends of the cell, centromere first

Question 31

What happens to the cell in the telophase stage of mitosis

Answer 31

The chromatids reach the opposite poles on the spindle They uncoil and become long and thin again - called chromosomes again Nuclear envelope forms around each group of chromosomes, now 2 nuclei

Question 32

What happens in cytokinesis

Answer 32

The cytoplasm divides In animal cells, cleavage furrow forms to divide the cell membrane There are now two daughter cells (genetically identical to the original)

Question 33

When does cytokinesis start

Answer 33

Usually begins in anaphase

Question 34

When does cytokinesis end

Answer 34

Telophase

Question 35

As mitosis begins the chromosomes are made of what

Answer 35

2 separate strands called chromatids 1 centromere

Question 36

How can you observe the cell cycle

Answer 36

By staining chromosomes