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Read the following four statements, A, B, C and D and select the right option having both correct statements.
STATEMENTS:
(A) Z scheme of light reaction takes place in presence of PS I only.
(B) Only PS I is functional in cyclic photophosphorylation.
(C) Cyclic photophosphorylation results into synthesis of ATP and $NADPH_2$
(D) Stroma lamellae lack PS II as well as NADP.
STATEMENTS:
(A) Z scheme of light reaction takes place in presence of PS I only.
(B) Only PS I is functional in cyclic photophosphorylation.
(C) Cyclic photophosphorylation results into synthesis of ATP and $NADPH_2$
(D) Stroma lamellae lack PS II as well as NADP.
A
B and D
B
A and B
C
B and C
D
C and D
Detailed Solution
(A) is wrong: the Z scheme (non-cyclic electron flow) needs both photosystems, PS II first and then PS I, connected through the electron transport chain.
(B) is correct: when only PS I is functional, the electron is circulated within the photosystem and cyclic photophosphorylation occurs.
(C) is wrong: cyclic photophosphorylation results only in the synthesis of ATP; $NADPH + H^+$ is not formed.
(D) is correct: the stroma lamellae membranes lack PS II as well as the enzyme NADP reductase; this is where cyclic photophosphorylation takes place.
Hence the correct statements are B and D.
(B) is correct: when only PS I is functional, the electron is circulated within the photosystem and cyclic photophosphorylation occurs.
(C) is wrong: cyclic photophosphorylation results only in the synthesis of ATP; $NADPH + H^+$ is not formed.
(D) is correct: the stroma lamellae membranes lack PS II as well as the enzyme NADP reductase; this is where cyclic photophosphorylation takes place.
Hence the correct statements are B and D.