Food chains

Question 1

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

Answer 1

The sun

Question 2

Food chain vs food web

Answer 2

Food chain: a chart/chain showing the flow of energy (food) from one organism to the next beginning with a producer.

Food web: a network of interconnected food chains

Question 3

Types of consumers

Answer 3

Herbivore as an animal that gets its energy by eating plants

Carnivore as an animal that gets its energy by eating other animals

Question 4

Food chain trophic levels

Answer 4

1. Producer: as an organism that makes its own organic nutrients, usually using energy from sunlight, through photosynthesis
2. Primary consumer
3. Tertiary consumer
4. Quaternary consumer

Question 5

What does the arrows indicate in a food chain?

Answer 5

WHERE the energy is going/being transferred. It shows the energy flow

Question 6

What must ecosystems consist of?

Answer 6

Consumers – an organism that gets its energy by feeding on other organisms.

Decomposers – an organism that gets its energy from dead or waste organic matter (i.e bacteria and fungi) They decay dead materials in order to recycle nutrients and are mostly found in the SOIL.

Producer – plants which photosynthesise. They supply energy for the ecosystem.

Physical environment – includes all non-biological components. Water, soil, temperature etc.

Question 7

Why do most food chains consist of less than 5 trophic levels?

Answer 7

There is only 10% flow of energy from one trophic level to the next higher level. The loss of energy at each step is so great that very little usable remains/nutrients that can be transferred after 4/5 trophic levels.

This also because most of the energy is lost through biological processes such as respiration or finding food (MRSGREN)

There is insufficient energy to support more trophic levels, hence only 4 to 5 trophic levels are present in each food chain.