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 parts called pinnae. When the leaf is touched, the pinnae fold inwards and the leaf closes. Fig. 4.1 shows an open leaf of M. pudica before it is touched, whereas Fig. 4.2 shows the same leaf after closing in response to touch.
(a)[3]
Describe how the mechanism shown in Fig. 4.3 is different from the mechanism responsible for 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]
Describe the similarities and differences between cyclic photophosphorylation and non-cyclic photophosphorylation.
Worked solution & mark scheme
This 11-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Touch stimulates the sensory hairs” …