Energy in biomass
Food chains show the feeding relationships between living things: for example, grass seed is eaten by a vole, which is eaten by a barn owl.
A food chain shows what eats what in a particular habitat. Pyramids of biomassreveal the mass of living material at each stage in a chain. The amount of material and energy decreases from one stage to the next. The arrows between each item in a food chain always point in the direction of energy flow - in other words, from the food to the feeder.
Radiation from the Sun is the ultimate source of energy for most communities of living things. Green plants and algae absorb some of the Sun’s light energy and transfer this energy to chemical energy. This happens during photosynthesis, and the chemical energy is stored in the substances that make up the cells of the plants or algae. The other organisms in a food chain are consumers, because they all get their energy and biomass by consuming (eating) other organisms.
It helps if you can recall the meaning of some common words used with food chains. This table shows some of these words.
Common words used with food chains and their meaning
WordMeaning producers green plants and algae
they make food by photosynthesis
primary consumers usually eat plant material - they are herbivores
for example rabbits, caterpillars, cows and sheep
secondary consumers usually eat animal material - they are carnivores