How is energy transferred to the next trophic level?

Question 1

Is all energy transferred to the next trophic level?

Answer 1

No

Question 2

What percentage of energy is lost?

Answer 2

90%

Question 3

What percentage of energy is never taken in?

Answer 3

60%

Question 4

What is the first reason why 60% of energy isn’t taken in?

Answer 4

Plants can’t use all wavelengths of light

Question 5

What is the second reason why 60% of energy isn’t taken in?

Answer 5

Some light is reflected and some passes straight through leaves

Question 6

What is the third reason why 60% of energy isn’t taken in?

Answer 6

Some sunlight is not used because it hits part of the plant that can’t photosynthesis

Question 7

What is fourth reason why energy isn’t taken in?

Answer 7

Some plants are not eaten so its passed to decomposers

Question 8

What is the fifth reason why energy isn’t taken in?

Answer 8

Some plants are indigestible so pass through organisms and come out as waste
-Also passes to decomposers

Question 9

How much of energy is taken in (Gross Productivity)?

Answer 9

40%

Question 10

How much of the total energy taken in is lost?

Answer 10

30%

Question 11

How is this 30% of energy lost?

Answer 11

From respiration for movement and body heat (respiration loss)

Question 12

What happens to the other 10% of energy?

Answer 12

Becomes available biomass (net productivity)

Question 13

What is the equation of net productivity?

Answer 13

Gross Productivity - Respiratory Loss

Question 14

What is the equation to calculate the efficiency of energy/biomass transfer between trophic levels?

Answer 14

(energy/biomass in above trophic level ÷ energy/biomass in below trophic level ) x100

Question 15

How can we calculate the amount of energy in a trophic level?

Answer 15

By measuring the dry mass of organisms

Question 16

How do we measure the dry mass of the organisms?

Answer 16

1)Calculate the amount of biomass in a sample of organisms
2)Multiply results from sample by size of total population
3)Gives the total amount of energy in the organisms at that trophic level
4)Difference in energy between the levels is the amount of energy transferred

Question 17

What is the problem with this method?

Answer 17

Consumers may take in energy from other sources

Question 18

What can human activities increase?

Answer 18

The transfer of energy

Question 19

What do some farming methods increase?

Answer 19

Productivity by increasing energy transfer

Question 20

What is the first farming method that increases productivity for plants?

Answer 20

Insecticides kill insects and pests that eat and damage crops

Question 21

What is the second farming method that increases productivity?

Answer 21

Herbicides kill weeds that compete with crops for energy

Question 22

What is the third farming method that increases productivity for plants?

Answer 22

Fungicides kill fungal infections that damage crops

Question 23

What is the fourth farming method that increases productivity for plants?

Answer 23

Introduce natural predators to eat pest species. This means crops lose energy and biomass increasing productivity

Question 24

What is the fifth farming method that increases productivity for plants?

Answer 24

Fertilisers provide crops with minerals needed for growth. Crops use up minerals as they grow, fertilisers replace these in the soil

Question 25

What is a farming method that increases productivity for livestock?

Answer 25

Rearing of livestock intensively involved the controlling conditions they live in so more energy is used for growth and less for other activities

Question 26

What are the two things rearing is able to do?

Answer 26

-Can provide high energy food to increase energy input
-Can keep livestock warm and limit movement so energy is not wasted

Question 27

What is the benefit of intensive farming?

Answer 27

More food is produced in a short space of time at a lower cost

Question 28

What is the ethical issue with intensive farming?

Answer 28

Has unnatural conditions and cause pain,distress and increases spread of disease