Biology 9700 · AS & A Level · Photosynthesis as an energy transfer process

Photosynthesis as an energy transfer process — practice question

In flowering plants, the light-dependent reactions are performed by photosynthetic pigments that are classified into two groups: primary pigments and accessory pigments.
(a)[2]

Outline the role of accessory pigments in the light-dependent reactions.

(b)[4]

Photosynthetic pigments are organised into photosystems. There are two photosystems, PSI and PSII. PSI is involved in cyclic photophosphorylation but PSII is not. Outline the differences between cyclic and non-cyclic photophosphorylation.

(c)

The rate of photosynthesis is influenced by several environmental factors. Fig. 8.1 shows how temperature affects the rate of photosynthesis.

(c(i))[2]

Explain why the rate of photosynthesis plateaus at $30\,^{\circ}\text{C}$.

(c(ii))[1]

On Fig. 8.1 extend the curve to show what would happen to the rate of photosynthesis if the temperature were increased to $70\,^{\circ}\text{C}$.

(c(iii))[2]

Explain the reason for extending the curve like this.

(d)[4]

A palisade mesophyll cell is adapted for photosynthesis. The table below gives some adaptations of a palisade mesophyll cell. Complete the table to show how these adaptations assist the cell in photosynthesis.

Worked solution & mark scheme

This 15-mark question has a full step-by-step worked solution and mark scheme. One marking point: Takes in light

  • Full mark scheme, point by point
  • Step-by-step worked solution
  • Write your answer & get it marked instantly by AI