Biology 9700 · AS & A Level · Homeostasis in plants
Homeostasis in plants — practice question
Sorghum and maize are both major food crops grown in dry parts of the world, yet sorghum can give higher yields than maize when water is very scarce. One reason is that sorghum plants have a smaller leaf area than maize, and another is that sorghum leaves contain rows of motor cells along the midrib on the upper side of the leaf, which enables the leaves to roll up.
(a)[3]
Explain how these two features help sorghum plants to grow in very dry conditions.
(b(i))[2]
With reference to Fig. 5.1, compare how digestible raw and cooked sorghum protein are.
(b(ii))[3]
Using your knowledge of protein structure and enzyme activity, suggest reasons for the differences you described in (i).
(i)[2]
Compare how digestible raw and cooked sorghum protein are.
(ii)[3]
Using your knowledge of protein structure and enzyme activity, suggest reasons for the differences you gave in (i).
Worked solution & mark scheme
This 13-mark question has a full step-by-step worked solution and mark scheme. One marking point: “cuts water loss through transpiration / evaporation” …