Energy flow, food chains and food webs: exam questions

What is the principal source of energy input to biological systems?

1. Chemical energy in glucose
2. Heat from the soil
3. Light energy from the Sun
4. Energy released by decomposers

In a food chain, what do the arrows show?

1. The direction in which animals move
2. The transfer of energy from one organism to the next
3. The number of organisms at each level
4. The organisms that are harmful to others

Describe the flow of energy through living organisms, starting with light energy from the Sun.

A food chain is: lettuce → snail → thrush → sparrowhawk (a) State the producer in this food chain. [1] (b) State the organism that is the secondary consumer. [1] (c) Name the organism that gets its energy directly from the thrush. [1] (d) State what the arrow between the lettuce and the snail represents. [1]

The table shows what each organism in a woodland food web eats. (a) State the number of different organisms that eat caterpillars. [1] (b) Name one organism that is both a primary consumer and a secondary consumer. [1] (c) Define the term food web. [1] (d) Suggest what happens to the number of owls if all the blue tits are killed by disease. [1]

Which organism gets its energy from dead or waste organic material?

1. A producer
2. A herbivore
3. A decomposer
4. A secondary consumer

Fishing boats catch large numbers of a fish that is eaten by seals and that eats small crustaceans. (a) State the term for catching a species faster than it can replace itself. [1] (b) Describe the effect of this on the seal population and explain your answer. [2] (c) Describe two ways in which introducing a foreign species to a habitat can affect the food web. [2]