Biology 9700 · AS & A Level · Photosynthesis as an energy transfer process
Photosynthesis as an energy transfer process — practice question
Mimosa pudica leaves are composed of several structures called pinnae. When the leaf is touched, the pinnae fold, causing the leaf to shut. Fig. 4.1 shows an open leaf of M. pudica before it is touched. Fig. 4.2 shows the same leaf after it has closed following touch.
(a)[3]
Describe how the mechanism shown in Fig. 4.3 differs from the mechanism causing the closure of the modified leaves in Venus fly traps.
(b)[2]
Explain why the rate of photosynthesis falls when the leaves of M. pudica close.
(c)[6]
Outline how cyclic photophosphorylation and non-cyclic photophosphorylation are similar and how they differ.
Worked solution & mark scheme
This 11-mark question has a full step-by-step worked solution and mark scheme. One marking point: “sensory hairs are touched” …