Paper 2

Question 1

Suggest how organic fertilisers improve the yield of plant crops

Answer 1

1. Broken down by fungi
2. Add nitrate, phosphate and potassium to the soil
3. Lack of minerals in the soil is a limiting factor of growth

Question 2

Suggest how the excessive use of inorganic fertilisers on farmland can cause a reduction in biodiversity

Answer 2

1. Fertiliser promotes growth of one species

2. Reduction in soil quality over time so plants cannot grow

Question 3

Explain why a reduction in biodiversity may present problems for agriculture in the future

Answer 3

1. Limits ecosystems ability to cope with environmental change
2. Loss of genetic diversity, which is found in the wild
3. Loss of pest predators

Question 4

A measure of relative numbers of individuals in each species

Answer 4

Species eveness

Question 5

The frequency of occurrence of plants in a particular area

Answer 5

Abundance

Question 6

The number of species present in a particular area

Answer 6

Species richness

Question 7

Outline the advantages for using a seed bank instead of adult plants to conserve an endangered species

Answer 7

1. Seeds can be transported easily
2. Lower maintenance costs of seeds than adult plants
3. Seeds less susceptible to disease
4. The seeds are more likely to survive for a longer period of time

Question 8

What molecules cannot be digested by humans and are egested?

Answer 8

Cellulose

Question 9

Explain why nitrogen fertiliser needs to be applied to farmland

Answer 9

1. Application of nitrogen replaces lost nitrogen
2. Nitrogen required for proteins and growth in plants.
3. High levels of nitrogen increases the fertility of the soil and therefore creates higher crop yields