Topic 2 Cells and control: mitosis, cancer,cell differentiation

Question 1

What is mitosis?

Answer 1

A type of cell division for growth and repair in which a diploid cell copies itself and finally divides into two identical diploid daughter cells, which are clones of eachother.

Question 2

Name all the stages of mitosis in order

Answer 2

Interphase, Prophase, Metaphase, Anaphase, Telophase and cytokinesis.

Question 3

What happens during interphase?

Answer 3

Cell spends most of its life in thi sstage, DNA in chromosomes copies itself ready for mitosis

Question 4

What happens during prophase?

Answer 4

DNA in chromosomes and their copies are pulled to different ends of the cell.

Question 5

What happens during metaphase?

Answer 5

Chromosomes and their copies line up in the middle of the cell

Question 6

What happens during anaphase?

Answer 6

Chromosomes and their copies are pulled to different ends of the cell

Question 7

What happens during telophase?

Answer 7

New membranes form around the chromosomes at each end of the cell.

Question 8

what happens during cytokinesis?

Answer 8

The cell membrane pinches in and eventually divides into two daughter cells.

Question 9

How many pairs of chromosomes are there in a diploid human body cell?

Answer 9

23

Question 10

What happens when a cell becomes cancerous?

Answer 10

It begins to grow and divide uncontrollably. New cells are produced even if they body does not need them. A group of canerous cells produces growth called a tumour.

Question 11

What are the two types of tumors called?

Answer 11

Benign and malignant

Question 12

Describe a Benign tumour.

Answer 12

Grow slowly, usually grow within a membrane so it can easily be removed, and do not invade other parts of the body.

Question 13

Describe a Malignant tumour.

Answer 13

Grow quickly, invade neighbouring tissues and can spread to other parts of the body in the bloodstream. As the tumour grows, cancer cells detatch and can form secondary tumours in other parts of the body, this process is called metastrasis .

Question 14

How are Carcinogens a cause of cancer?

Answer 14

They are chemicals which cause cancer by damaging DNA and cause mutations to occur. Several mutations are required for cancer to develop which is why you are more likely to develop it as you get older.

Question 15

What are risk factors for various types of cancer?

Answer 15

1) Exposure to Ultraviolet Radiation (ionising) leading to skin cancers
2) Exposure to chemical carcinogens

Question 16

where does mitosis take place in plants?

Answer 16

Meristems found in the tips of shoots and roots. Here, new cells are formed. plant cells are also able to become longer as they grow, this is cell elongation and occurs throughout the plant.