key area 4 - energy in ecosystems

Question 1

what is a pyramid of energy?

Answer 1

a pyramid of energy shows the total quantity of available energy stored in the biomass of organisms at each level in the food chain of an ecosystem per year

Question 2

why do numbers decrease as you go up the food chain?

Answer 2

because 90% of energy is lost at each stage in the food chain so only 10% is available fro growth

Question 3

what is a food chain?

Answer 3

organisms in an ecosystem are linoed together in food chains and food webs. they start with producers which obtain their energy from the sun. energy is oassed fron ine organism to the next, the arrows represent the direction if energy transfer from ine organism to another.

Question 4

in a food chain, how is 90% of the energy lost?

Answer 4

heat, movement, undigested materials, a small quantity is used for growth

Question 5

a pyramid of numbers shows the total number of individual organisms at each level in the food chaij if an ecosystem.