Lesson eLearning

Which pigment in the light‑harvesting complex of Photosystem I is responsible for transferring the primary electron to plastocyanin?

medium MCQ 3 marks Class 11 · Biology · Photosynthesis in Higher Plants
  1. Chlorophyll b
  2. Chlorophyll a
  3. Phycocyanin
  4. Carotenoid
Answer
Chlorophyll a

The correct answer is Chlorophyll a — Therefore the pigment that transfers the electron is chlorophyll a.

Step-by-step solution

  1. Identify the primary electron donor in PSI – the reaction centre pigment P700.
  2. Recognise that P700 is a chlorophyll a molecule.
  3. P700 donates the electron to the primary acceptor, which ultimately reduces plastocyanin.
  4. Therefore the pigment that transfers the electron is chlorophyll a.
Common mistake: Confusing PSI with PSII or misidentifying the pigment

Concept tested: Electron transport in Photosystem I

Published · How this solution was prepared and checked

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