Minerals known to be required in large amounts for plant growth include:
1. phosphorus, potassium, sulphur, calcium
2. calcium, magnesium, manganese, copper
3. potassium, phosphorus, selenium, boron
4. magnesium, sulphur, iron, zinc

Which one of the following is not an essential mineral element for plants while the remaining three are?
1. Phosphorus
2. Iron
3. Manganese
4. Cadmium

Which one of the following is not a micronutrient?

1. Molybdenum

2. Magnesium

3. Zinc

4. Boron

Which one of the following elements is not an essential micronutrient for plant growth?
1. Mn
2. Zn
3. Cu
4. Ca