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Question 18M.2.HL.TZ2.c

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Date May 2018 Marks available [Maximum mark: 3] Reference code 18M.2.HL.TZ2.c
Level HL Paper 2 Time zone TZ2
Command term Describe Question number c Adapted from N/A
c.
[Maximum mark: 3]
18M.2.HL.TZ2.c

All living organisms depend on a continuous supply of energy.

Describe the reasons for the shape of a pyramid of energy.

[3]

Markscheme

a. pyramid of energy has stepped shape with largest bottom step being producers, then first consumer, second consumer, etc 

b. light energy «from sun» converted to chemical energy in carbon compounds by photosynthesis 

c. energy released by respiration is used in living organisms AND converted to heat 

d. heat «energy» is lost from ecosystems 

e. approximately 10 % of energy in trophic level converted into new material for next level 

f. energy also lost as undigested material/uneaten material/feces/excretion 

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