Chapter 1- Cell Division

Question 0

What is mitosis?

Answer 0

Mitosis is the division of the nucleus in two genetically identical daughter nuclei

Question 1

What is interphase?:G1?

Answer 1

Growth of cell and increase in number of organelles

Question 2

Interphase: What is S phase

Answer 2

Replication of chromosomes copies remaining attached to one another

Question 3

Interphase: What is G2?

Answer 3

Further growth occurs, organelles increase in number, DNA condenses to form visible chromosomes, micro tubules begin to form

Question 4

What happens after G2?

Answer 4

After interphase and the DNA has replicated, the cell moves into mitosis

Question 5

What happens during mitosis

Answer 5

During mitosis the replicated chromosomes separate and move to opposite poles of the cell thus providing the same genetic material to each of these locations

Question 6

What are the 4 phases of mitosis

Answer 6

Prophase, metaphase, anaphase, telophase

Question 7

What 2 things happens in metaphase

Answer 7

1) all replicated chromosomes (chromatid pairs) align at equator
2) all chromatid pairs have myofibril network attracted to centromere

Question 8

What 4 things happen in prophase

Answer 8

1) centriole replicates and moves towards ‘poles’ of the cell
2) develops myofibril network (proteins attach to centromere)
3) nuclear membrane breaks down
4) condensation of chromosomes

Question 9

What 1 thing happens in anaphase

Answer 9

1) myofibril network pulls chromatid pairs apart and moves a set of chromosomes to each ‘pole’

Question 10

What 4 things happen in telophase?

Answer 10

1) centriole remaining in each new prospective cell
2) nuclear membrane reforming
3) chromosomes de condense
4) breakdown of myofibril network

Question 11

What happens after mitosis

Answer 11

Cytokinesis

Question 12

What happens in animal cytokines?

Answer 12

1) the plasma membrane pulls inwards around the equator of the cell to form a cleavage furrow
2) when the cleavage furrow reaches the centre, the cell is pinched apart into two daughter cells

Question 13

What are cyclins?

Answer 13

Group of proteins that ensure that tasks are performed at the correct time and that the cell only moves onto the next stage of the cycle when it is appropriate

Question 14

What do tumour suppressor genes produce?

Answer 14

Proteins which inhibit cell devision

Question 15

mutations to tumour suppressor genes result in?

Answer 15

Uncontrolled cell devision = tumour

Question 16

What can tumours do?

Answer 16

Grow in size which can cause damage to local tissue and may spread to other parts of the body

Question 17

How can tumours form?

Answer 17

Because of random changes to the base sequences of genes

Question 18

What are carcinogens?

What time of tumour are they?

Answer 18

1) Chemicals and agents that cause cancer

2) malignant tumours

Question 19

What are oncogenes?

Answer 19

Few genes that can become cancer-causing after mutating

Question 20

In a normal cell oncogenes are involved in the control of the cell cycle and cell devision therefore mutations in then cause what?

Answer 20

Result in uncontrolled cell decision and tumour formation

Question 21

What is a primary tumour?

Answer 21

When a tumour cell has been formed it divides repeatedly to form Two, then four, then eight cells and so on

Question 22

What is metastasis?

Answer 22

The movement of cells from a primary tumour to set up secondary tumours in other parts of the body

Question 23

What else involes mitosis?

Answer 23

Growth, embryonic development, tissue repair and asexual reproduction