2022 P1 BIO

pg28

C

Mineral ions enter the plant through the roots. Mineral ions in the soil are in lower concentrations than in the vacuoles of root hair cells. Describe how mineral ions are taken up by root hair cells. (3)

State how the age of the layers in a peat bog can be determined. (1)

C-14dating

Explain why the conditions in peat bogs prevent decomposition. (3)

Describe the primary structure of a protein. (2)

0.5×0.5

Draw and label a mitochondrion. (2)

Explain why a fertilised egg cell will contain only maternal mitochondria. (2)

) Using IVF, it is possible to produce an embryo that does not have the mitochondrial disease. The nucleus is removed from a donor egg cell from another individual. The nucleus from a fertilised egg from a mother with the mutation is then placed in the egg cell from the donor. (i) Explain why the resulting embryo does not develop mitochondrial disease. (2)

Comment on the inheritance of parental characteristics in offspring produced in this way. (3)

• mitchondria from donor

• none carry mutation

• {DNA/genetic material / chromosomes} in the nucleus comes from (the sperm and egg of) the parents (1) • characteristics determined by DNA in the nucleus will be inherited from the parents (1) • any characteristic controlled by mitochondrial DNA would be inherited from the donor (1)

BA

Explain why, following a measles infection, it may be advisable for children to repeat other vaccinations they have had. (3)

Explain the effect of using anti-viral drugs to treat HIV on the number of deaths from TB. (6)

Biodiversity can be measured by the number of

different species in a habitat.