Energy and biomass in food chains Flashcards
What is the primary source of all energy in biomass (living material)?
Where is this energy stored?
Light energy which is converted into chemical energy.
This energy is stored in the substances that make up the cells of the plants
Give three reasons why the biomass at each stage of a food chain is less than it was at the previous stage.
1) Not all food can be digested, so some energy is lost in the organisms’ faeces or as urea in urine (waste materials).
2) Much of the energy from respiration is eventually transferred into the surroundings (through heat loss, etc).
3) In animals that need to keep their body temperature constant, energy from the previous stage is used simply to keep the animal at its normal body temperature.
What do all organisms take up from their environment, and how is this returned to the environment?
If it was not returned, what would happen?
All organisms take up nutrients for growth and other processes, which are then returned either in waste or when the organism dies and decays.
The nutrients would run out.
What type of organisms start the process of decay and how do they do this?
What happens next in the process of decay?
Why is this important?
What are the optimum (fastest) conditions for decay?
Detritus feeders (such as some types of worm) may start the process of decay by eating dead animals or plants and producing waste materials.
Microorganisms called decomposers digest and slowly break down the waste or dead plants and animals.
All of the waste and dead organisms are recycled, returning nutrients to the soil.
Warm, moist and aerobic (plenty of oxygen)
Describe a stable community
Where the processes that remove materials are balanced by processes that return materials; the materials are constantly cycled.
In the carbon cycle, in what three main ways do green plants and algae use carbon?
1) They remove it from the environment for photosynthesis in the form of carbon dioxide.
2) The carbon is then used to make carbohydrates, fats and proteins, which make up their bodies.
3) When they respire, some of it becomes CO2 and is released back into the atmosphere
In the carbon cycle, in what two ways is carbon used by animals?
1) They eat the plants and algae some of the carbon becomes and build the carbon into their bodies.
2) When the animals respire they release some carbon as CO2 into the atmosphere.
In the carbon cycle, when plants, algae and animals die, what happens to them and to the carbon?
Some animals and microorganisms feed on their bodies, ingesting the carbon stored in the fats and proteins. They respire, releasing CO2.
How can CO2 be released into the atmosphere?
Combustion of wood and fossil fuels
Respiration
What is biomass?
Biomass is the mass of living material in plants and animals.
What is a pyramid of biomass?
A pyramid of biomass represents the mass of the organisms at each stage of the food chain.
Why doesn’t all the energy taken in by an organism result in the growth of that organism?
Because there is energy wastage between each stage of a food chain.
How can humans recycle waste?
Humans can recycle waste in sewage treatment plants and compost heaps.
What are the best conditions for composting and what may gardeners add to compost heaps to speed up the process?
1) The waste should be allowed to mix with oxygen and moisture.
2) Energy should be allowed to escape by heating the surroundings.
Worms and layers of garden soil
What is contained in peelings from the kitchen and grass cuttings and tree clippings from the garden?
Organic waste
