Mineral Ions in Plants

IGCSE Edexcel Biology
2.22 Mineral Ions
Key Concept: Plants need mineral ions such as magnesium and nitrates for healthy growth.

Section A: Roles

1. Explain why plants need magnesium ions. [2]
2. Explain why plants need nitrate ions. [2]

Section B: Deficiency

3. Describe one symptom of magnesium deficiency and one symptom of nitrate deficiency. [4]

Section C: Application

4. Explain how fertilisers can improve plant growth. [2]
Total marks: 10

Mark Scheme

1. Magnesium is needed to make chlorophyll [2]
2. Nitrates are needed to make amino acids and proteins [2]
3. Magnesium deficiency causes chlorosis/yellowing; nitrate deficiency causes stunted growth or yellowing (one each) [4]
4. Fertilisers add mineral ions for growth and photosynthesis, increasing yield [2]