Energy In Ecosystems Flashcards
(32 cards)
What are consumers ?
Animals and fungi that cannot produce food from sunlight therefore they must eat other animals and plants for energy to live
What do herbivores eat ?
Only plant materials (e.g. Sheep)
What do carnivores eat ?
Only animal materials (e.g. Dog )
What do omnivores eat ?
Mixture of plant and animal materials (e.g. Man)
What do arrows in a food chain indicate ?
The direction of energy flow
How much energy is lost at each stage in a food chain and how much energy is passed on?
90% lost
10% passed on
How can energy be lost (3)
Movement
Heat
Undigested food
What can be said about short food chains ?
More efficient
What can we say about the greater the number of links ?
Less energy is passed on at each stage
What is a pyramid of numbers ?
A diagram that shows the number of organisms at each level in a food chain
What 2 trends do we see as we move up the pyramid ?
Number of organisms decreases
Size of organisms increases
What does a pyramid of biomass show?
The total mass of all the organisms at each stage in a food chain
What is the biomass at each level dependent on ?
The energy passed on at each stage in the food chain and can vary throughout the year
What is a pyramid of energy based on?
Productivity
How is a pyramid of energy measured as?
Grams of dry mass per metre squarer per year and then is converted into energy equivalent in kJ per metre squared per year (kJ/m2/year)
What is a pyramid of energy ?
A diagram that shows the amount of energy available at each level in a food chain
What are producers ?
Green plants which produce their own food by changing the sun’s light energy into chemical energy by photosynthesis
Why is nitrogen an essential element ?
Used to make DNA , amino acids and proteins
What percentage of the air is nitrogen ?
80%
What form do green plants absorb nitrogen ?
Nitrates from the soil and use it to make proteins
What is the nitrogen cycle is essential to provide ?
Nitrates for plants to absorb and use
What does the nitrogen cycle ensure ?
A continuous supply of nitrogen for years to come
What does nitrogen fixing bacteria do?
Convert nitrogen gas to nitrate
Can be found in root nodules of clover plant s
What do decomposers do ?
Convert protein to ammonium compounds
