Energy Transfer Between Trophic Levels

Question 0

Define gross production

Answer 0

The total quantity of energy that the plants in a community convert to organic matter

Question 1

Why is not all of the Suns energy photosynthesised by plants?

Answer 1

Over 90% of the Suns energy is reflected back into space, not all wavelengths of light can be absorbed and light may not fall on a chlorophyll molecule

Question 2

Define net production

Answer 2

The rate at which energy is stored (Gross production - Respiratory losses)

Question 3

Why is there only a low percentage of energy transferred at each stage of a food chain?

Answer 3

Some of the organism is not eaten, some parts cannot be digested, some is lost in excretion and some is lost as heat energy

Question 4

Give 3 indications that the energy transfer between Trophic levels is inefficient

Answer 4

Most food chains have only four or five Trophic levels, the total mass of organisms is less at higher Trophic levels, the total amount of energy stored is less at each level

Question 5

What is the energy available usually measured in?

Answer 5

Kilojoules per square metre per year (kJ m-2 year-1)

Question 6

What is the formula for energy transfer?

Answer 6

Energy available after the transfer / Energy available before the transfer x 100