Question

Which of the following is correct for the given figure?

• A. The part labelled 'b' is called thylakoid.
• B. The part labelled 'c' is called granum.
• C. The part labelled 'a' is the site of dark reaction.
• D. The part labelled 'a' 'b' and 'c' all possess chlorophyll containing photosynthetic pigments.

Answer 1

The correct option is C The part labelled 'a' is the site of dark reaction.

Dark reactions make use of these organic energy molecules (ATP and NADPH). This reaction cycle is also called as Calvin Benson Cycle, and it occurs in the stroma (a). ATP provides the energy, while NADPH provides the electrons required to fix the CO${}_2$ (carbon dioxide) into carbohydrates.
Light reactions need light to produce organic energy molecules (ATP and NADPH). They are initiated by coloured pigments, mainly green coloured chlorophylls.