Environment Flashcards
What do food chains show?
Food chains show the feeding relationships in a habitat.
What do pyramids of biomass show?
Pyramids of biomass are charts that show the mass of living organisms at each step in a food chain.
When is energy lost in a food chain?
Energy is lost moving up in a food chain, and this limits the length of the chain - so it’s more efficient to feed people with plants than with meat.
What animals are mostly used in a food chain and why?
Food chains always start with producers, which are almost always green plants. The other organisms in the food chain are consumers – they all get their energy and biomass by consuming (eating) other organisms.
Why are food chains short?
Most food chains are quite short, and they rarely consist of more than four steps. This is because a lot of energy is lost at each step. After about three steps, very little energy is still available for use by living organisms. This also explains why there are few organisms at the top of food chains, compared with those lower down.
What is biomass?
The dry mass of an organism is called its biomass.The total biomass at a particular step in a food chain is always less than the total biomass at the step before it.
Name six other ways energy can be lost in food chain.
sunlight is reflected off leaves instead of being used for photosynthesis
energy is lost through respiration as heat
energy is lost because of excretion and defecation
energy is used for movement and transport
Why is it better for humans to eat cereals in the morning rather than meat?
Wheat (used in cereals), is first on the food chain because it is plant. Whereas a plant has been eaten by an animal, which is used for meat. Therefore energy has been lost in the process.
Why is organic food more expensive?
More labour is needed
The crop yields may be smaller
Organic produce may be more difficult to transport without being spoiled.
Name three things animals compete for.
Food
Water
Space
Name four things plants compete for.
Light Water Space Mineral salts They don't compete for food because of photosynthesis.
When are animals interdependent?
When they are within an ecosystem.
How is prey adapted for being hunted?
Prey species, must be well adapted to escape their predators, if enough of them are to survive for the species to continue.
How is a predator adapted for hunting?
Predator species need to be adapted for efficient hunting if they are to catch enough food to survive.
