B2

Question 1

Why does mitosis occur?

Answer 1

• replace worn out cells
• repair damaged tissue
• growth

Question 2

What are the 4 stages of mitosis?

Answer 2

DNA Replication, movement of chromosomes, cytokinesis and growth of the daughter cell

Question 3

What happens to the SA:V Ration as the size of an organism increases?

Answer 3

Decreases

Question 4

What is lysis?

Answer 4

Cell bursts

Question 5

What is crenation?

Answer 5

Cell shrivels

Question 6

What is Turgid?

Answer 6

Cell increases turgor pressure causing it to become rigid

Question 7

What is flaccid

Answer 7

Little pressure. Cell remains same

Question 8

What is plasmolysis?

Answer 8

Cell contents collapse away from the cell wall

Question 9

How does mitosis occur?

Answer 9

1) DNA replicates
2) chromosomes line up in the centre
3) two identical copies of chromosome separate and move to opposite ends of the cell
4) each end now contains full set of identical chromosomes
5) two new nuclei from. Cytoplasm pinches and two new daughter cells are formed.

Question 10

How does the transpiration stream work?

Answer 10

1) water moves up into the roots from the soil by osmosis
2) water moves up to the xylem vessels
3) water moves up xylem to the leaves to replace lost water
4) water evaporates from the cell surfaces inside the leaf into air spaces
5) water diffuses out of the leaf through the stomata