Paper 2 Biology

Mitosis is important in producing more cells for plant growth. Describe THREE OTHER WAYS in which mitosis is important in plants (3 marks)

The virus that causes the infectious disease influenza has two antigens, H and N. Antibodies are produced in response to an infection by this virus. The antibodies are specific for either antigen H or for antigen N.

Describe how the structure of an antibody molecule allows it to be specific for one antigen, such as H or N. (3 marks)

State the name of the pathogen that causes cholera and describe how it is transmitted (3 marks)

Collagen is a structural protein and haemoglobin is a globular protein. Outline how the structure of collagen differs from that of haemoglobin (4 marks)

An investigation was carried out to find out how the activity of starch phosphorylase varied with temperature, when free in solution and when immobilised in alginate. The results are shown in the graph.

Compare the results for the enzyme activity when free in solution and when immobilised. (4 marks)

Outline the role of cell surface membranes in living cells (4 marks)