AQA Additional Biology - Energy flows

Biomass - the mass of living material in plants and animals

A pyramid of biomass represents the mass of the organism at each stage in a food chain.

For example : one bush may have many inscects feeding on it but th emass of the bush is far greater than the mass of the insects.

pyramids of biomass' look like a pyramid shape.

Top tip - the examiner wants you to be able to explain why a pyramid of biomass is likely to give a more accurate picture of a food chain.

For a whole range of reasons, there is energy lost between each stage of a food chain. This means that not all of the energy taken in by an orgaanism results in the growth of that organism.

Not all food can be digested.

Some is lost through different things like:

respiration - releases energy for living processes.

movement - the more something moves the more energt it uses and the less available for growth

Faeces - waste

The shorter the food chain, the less the energry will be lost. it is therefore more efficient for us to eat plants than is to eat animals.

We can artificially produce meat more efficiently by:

Preventing the animal from moving so it dosen't waste energy on movement

This is seen as cruelty by many people and its controversial

keeping the animal at warmer temperature so it dosent use as much energy from food to keep itself at a constant  temperature.

Photosynthesis removes CO2 from the atmosphere

Green plants and animals respire. This returns CO2 to the atmosphere

Animals eat gree plants and build the carbon into thie bodies. When plants or animls die microorganisms release CO2 back into the atmosphere.