HARD
Earn 100

What are the important events and end products of the light reaction?

Important Questions on Photosynthesis in Higher Plants

HARD
Identify and explain with the help of diagrammatic representation, type of photophosphorylation P700 (PS I) and P680 (PS II) both are involved.
EASY

During Z scheme electrons excited by absorption of light in PSI are transferred to the primary acceptors and therefore must be replaced. The replacements come directly from          

MEDIUM

Three cellular processes are listed below, Choose the CORRECT combination of processes that involve proton gradient across the membrane.
i Photosynthesis
ii Aerobic respiration
iii Anaerobic respiration

MEDIUM
Write any four points of differences between cyclic and non-cyclic photophosphorylation.
MEDIUM

Assertion (A): In PS I, the reaction centre, chlorophyll 'a' has an absorption peak at 700 nm, hence is called P700, while in PS II, it has absorption maxima at 680 nm and is called P680.

Reason (R): Calvin pathways occur in all photosynthetic plants, it does not matter where they have C3 or C4 pathways and the Calvin cycle described in three stages: Carboxylation, reduction and regeneration.

The correct answer is:

MEDIUM
How many molecules of ATP are required for the synthesis of 5 molecules of glucose during the Calvin cycle?
MEDIUM

Identify the labeled parts as 1, 2, 3, 4 in cyclic photophosphorylation?

Question Image

EASY
No. of ATP, O2 molecules and NADPH released in photophosphorylation when 12H2O molecules undergo photolysis
EASY
Where does photolysis of H2O occur? What is its significance?
MEDIUM
In a photoelectric effect experiment, a point source of light of power 3.2 mW emits photons each of which has 5 eV energy. The source is located at a distance of 0.8 m from the centre of a stationary metal disk having a work function of 3 eV. The metal disk has a radius of 8×10-3 m. Assuming that one photoelectron is emitted for every 106 photons striking the surface of the disk, how many photoelectrons are emitted every second?
HARD
How many matured trees are required to support the supply of oxygen to 42,000 people in a year?
HARD

Arrange the path of electrons from water to the phycocyanin in the light reaction.

i) Plastoquinone

ii) Excited P680*

iii) Cyt f

iv) Fe-S

v) Pheophytin

vi) Quinone

The correct sequence is

MEDIUM
Which one of the following options is true in photosynthesis?