June 2016 P1

Question 1

Describe how the complementary strand of HIV DNA is made (3)

Answer 1

Complementary nucleotides pair

DNA polymerase

Nucleotides join together and phosphodiester bonds form

Question 2

Describe how you would test for the presence of a lipid in a sample of food (2)

Answer 2

Emulsion test

Add ethanol and then add water to a sample of food and mix

If a white emulsion appears lipids are present

Question 3

Describe how ATP is resynthesised in cells (2)

Answer 3

From ADP and phosphate

By ATP synthase

During respiration / photosynthesis

Question 4

Give two ways in which the hydrolysis of ATP is used in cells (2)

Answer 4

Energy for protein synthesis

To add phosphate to other substances and make them more reactive

Question 5

HPV is the main cause of cervical cancer. A vaccine has been developed to protect girls and women from HPV.

Describe how giving this vaccine leads to production of antibody against HPV.

Answer 5

Vaccine contains antigen from HPV

Displayed on antigen presenting cells

Specific helper T cell stimulates specific B cell

B cell divides to give plasma cells

Plasma cell produces antibody