B1.5 Energy and Biomass in Food Chains Flashcards
What is biomass?
The mass of living material
Describe how the biomass at each stage of the food chain changes.
Biomass at each stage in a food chain is less than it was at the previous change.
What is a pyramid of biomass?
A diagram which shows how much biomass is at each stage of the food chain.
Why does the amount of material and energy contained in the biomass of organisms decreases at each successive stage in the food chain?
- Some energy is lost in the organisms waste materials (via faeces)
- energy lost via respiration as respiration releases energy
- energy is used for movement
- some energy is lost as heat to the surroundings
- some energy is used in maintenance and repair
- some organisms die rather than being eaten so are decomposed by microorganisms
Describe how green plants and algae use radiation from the sun
They absorb small amounts of the light that reaches them. The transfer from light energy to chemical energy is called photosynthesis. This energy is stored in substances that make up the cells of plants.
Why may some green plants and algae not get much energy from the sun?
lots of light may be reflected instead of absorbed
some of the light may have missed the chloroplasts
photosynthesis may be inefficient
Name the process which transfers energy from food into movement
respiration
Why may a farmer decide to move his calf indoors so that it will grow quicker?
It reduces the calfs movement. therefore it can use that energy for growth
it reduces the energy the calf will need to use to keep it warm and that energy can be used for growth
Why in shorter food chains, does a greater proportion of energy and biomass reach humans?
there are fewer stages
so less losses in waste such as faeces
and less energy lost in respiration and movement
