DISTINGUISH between autotroph and heterotroph
CONSTRUCT a food web containing up to 10 organisms, using appropriate information
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DESCRIBE what is meant by a food web
The food web is a diagram that shows how food chains are linked together into more complex feeding relationships.
DEDUCE the trophic level or organisms in a food chain and a food web
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STATE that saprotrophic bacteria and fungi recycle nutrients
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EXPLAIN reasons for the shape of the pyramids of energy
A pyramid of energy shows the flow of energy from the one trophic level to the next in a community. The units of pyramids of energy are, therefore, energy per unit are per unit time.
DISTINGUISH between autotroph and heterotroph
An autotroph is an organism that can synthesize their organic molecules from simple inorganic substances. They are producers. A heterotroph is a consumer and it obtains organic molecules from other organisms.
DISTINGUISH between consumers,detritivores and saprotrophs
Consumer: An organism that ingests other organic matter that is living or recently killed. Detritivore: An organism that ingests non-living organic matter. Saprotroph: An organism that lives on or in non-living organic matter, secreting digestive enzymes into it and absorbing the products of digestion.
EXPLAIN that energy enters and leaves ecosystems, but nutrients must be recycled
Energy can enter and leave an ecosystem but nutrients must be recycled. Sun light is the main source of energy on this planet. It is absorbed by photosynthesizing organisms, which convert light to chemical energy. Nutrients must be recycled by obtaining them from other organisms or products of organisms.
EXPLAIN the energy flow in a food chain
Energy losses between trophic levels include material not consumed or material not assimilate, and heat loss through cell reparation.
STATE that energy transformations are never 100% efficient
Energy transformations are never 100% efficient. Only chemical energy can be used by the next trophic level.
STATE that light is in the initial energy source for almost all communities
No reference to communities where food chains start with chemical energy is required
DEFINE trophic level
Trophic level: the trophic level of an organism is its position in the food chain. Producers, primary consumers, secondary consumers and tertiary consumers are examples of trophic levels.
DESCRIBE what is meant by a food chain, giving three examples, each with at least three linkages (four organisms)
•A food chain is a linear and simple feeding relation, where one organism has one type of food and is eaten by one type of organism. For example: Mosquito larva ----->beetle--------->mouse--------->snake Plankton--------->krill-------------->mullet------------->shark Earwig--------->lizard---------->shrew------------->owl Clams------->starfish----->sea otters-------->orcas
