Question

Which one of them is not a character of antennae?
(a) To make photosynthesis more efficient
(b) To make wider range of absorption of incoming light
(c) Provide electron to primary electron acceptor of photosystem
(d) Reaction center is not a part of it

Answer 1

Both photosynthetic species have Light Harvesting Complexes (LHC) in their photosynthetic apparatus. These increase the capacity for harvesting light and, in addition, have important regulatory functions. LHC are made of many pigment molecules. LHC is present within the PS-I and Ps-II. Each photosystem has all pigments except one molecule of chlorophyll a and forms a light harvesting system also called ‘antennae’.

Complete Step by step answer:
(a) The pigments in the antennae molecule help in making photosynthesis more efficient by absorbing different wavelengths of light.
So, option (a) is incorrect.
(b) Due to the presence of many pigments in the antennae, it is able to absorb a very wide range of incoming light.
Option (b) is incorrect.
(c) It does not provide electrons to the primary electron acceptor of the photosystem. The electron from LHC is picked up by an electron acceptor which passes it to an electron transport system.
Option (c) is correct.
(e) The reaction center is a single chlorophyll molecule that is not a member of the antennae.
Option (d) is incorrect.

Hence, the correct answer is (c).

Note: The reaction center is different in both the photosystems. PS-I chlorophyll a can absorb a light maximum of $700 nm$ wavelength and is called as $P700$, while PS-II has the absorption maxima at wavelength$680 nm$, hence called as $P680$. PS-I occurs in both cyclic and non-cyclic photophosphorylation whereas PS-II is found only in non-cyclic photophosphorylation.