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Question 18N.2.HL.TZ0.e.i

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Date November 2018 Marks available [Maximum mark: 2] Reference code 18N.2.HL.TZ0.e.i
Level HL Paper 2 Time zone TZ0
Command term Sketch Question number e.i Adapted from N/A
e.i.
[Maximum mark: 2]
18N.2.HL.TZ0.e.i

Boreal forests stretch across Canada, Russia and Scandinavia. This northern ecosystem accounts for 29 % of the world’s forest areas. The long, cold winters favour tall evergreen trees with either needles or scale-like leaves. These trees are wind-pollinated and their seeds are not enclosed in a fruit. The photograph shows a typical boreal forest in winter.

The boreal forests are situated close to the north pole and even in summer the intensity of sunlight is lower than at the equator. Sketch a graph showing the effect of light on the rate of photosynthesis, labelling the axes.

[2]

Markscheme

a. x-axis labelled as light intensity/amount of light AND y-axis labelled as rate of photosynthesis/rate of oxygen release/rate of carbon dioxide uptake ✔

b. curve starting at/slightly to the right of the x-axis origin and rising rapidly and then more slowly and plateauing but never dropping ✔

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