Fig. 2.1 shows a food chain from a river. (a) State the primary consumer in this food chain. (b) The microscopic plants can convert light energy into chemical energy. (i) Describe the process which is responsible for the conversion of light energy into chemical energy.

Here are the solutions to the questions:

a) State the primary consumer in this food chain.

In a food chain, the primary consumer is the organism that feeds on the producers.

• Microscopic plants are the producers (they make their own food).
• Small fish feed on the microscopic plants.
• Large fish feed on small fish.
• Birds feed on large fish.

Therefore, the primary consumer is the small fish.
$\boxed{\text{Small fish}}$

b) The microscopic plants can convert light energy into chemical energy.

(i) Describe the process which is responsible for the conversion of light energy into chemical energy.

The process responsible for converting light energy into chemical energy in plants is photosynthesis. During photosynthesis, plants use light energy to convert carbon dioxide and water into glucose (a form of chemical energy) and oxygen.

The process is photosynthesis.
Light energy is absorbed by chlorophyll and used to convert carbon dioxide and water into glucose (chemical energy) and oxygen.