Energy in ecosystems

Question 1

What do food chains/webs start with?

Answer 1

Food chains/webs start with plants (producers) which obtain their energy from the sun.

Question 2

What do the arrows in a food web/chain show?

Answer 2

Energy is passed from one organism to the next. The arrows in the food chain/web show the direction of energy flow.

Question 3

What is the source of all energy in food chains/webs?

Answer 3

The sun.

Question 4

What happens to the energy from one level of the food chain/web to the next?

Answer 4

The majority of energy is lost (around 90%) between one level of the food chain and the next.

Question 5

What are the main ways in which energy from a food chain can be lost?

Answer 5

Movement
Heat
Undigested material (e.g. skin and hair)

Question 6

How much energy is available from one level in the food chain to the next level?

Answer 6

Only a small quantity of the energy (around 10%) from one level in the food chain is available to the next level for growth.

Question 7

What does a pyramid of numbers show?

Answer 7

A pyramid of numbers shows the total number of individual organisms at each level in the food chain of an ecosystem.

Question 8

How do you read a pyramid of numbers?

Answer 8

The greater the length of the bar the greater the number of organisms at that stage of the food chain.

Question 9

What are irregular shapes of pyramids of numbers be represented as?

Answer 9

Irregular shapes of pyramids of numbers based on different body sizes can be represented as true pyramids of energy.

Question 10

What is a pyramid of energy?

Answer 10

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.