Topic 4.2 Energy Flow

Question 1

Trophic Levels

Answer 1

Lvl 1 Producer
Lvl 2 Primary consumer
Lvl 3 Secondary consumer
Lvl 4 Tertiary consumer

Question 2

Food chain

Answer 2

A food chain shows the linear feeding relationships between species in a community

Arrows indicate the transfer of energy

Question 3

Heat loss in ecosystems

Answer 3

By-product of cell respiration is heat which cannot be converted into energy by living organisms hence a loss of energy

Question 4

Energy loss

Answer 4

Energy is lost in excreted faeces and uneaten portions of the food

Question 5

Typically energy transformations are

Answer 5

10% efficient, 90% of available energy is lost between trophic levels

Question 6

Biomass

Answer 6

the total mass of a group of organisms – consisting of the carbon compounds contained in the cells and tissues

Question 7

Why can’t an ecosystem survive?

Answer 7

Higher trophic levels receive less energy / biomass from feeding and so need to eat larger quantities to obtain sufficient amounts

Because higher trophic levels need to eat more, they expend more energy (and biomass) hunting for food

If the energy required to hunt food exceeds the energy available from the food eaten, the trophic level becomes unviable