Read the following four statements, A, B, C and D and select the right OPTION having both correct statements…
Read the following four statements, A, B, C and D and select the right OPTION having both correct statements.
A. Z secheme 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 $\mathrm{NADPH}_2$.
D. Stroma lamellae lack PS-II as well as NADP.
B and D
A and B
B and C
C and D
Solution
Cyclic photophosphorylation is performed by PS-I only. In this process, an electron expelled by the excited photocentre, ie, $\mathrm{P}_{700}$ is returned to it after passing through a series of electron carriers.
PS-I is located on both the non-appressed part of grana thylakoids as well as stroma thylakoids, while PS-II is located in the appressed part of grana thylakoids only, stroma thylakoids lack PS-II.