Question

Photosynthesis pigment common to all algae
A. Chlorophyll b and carotene
B. Chlorophyll a and b
C. Chlorophyll a and carotene
D. Chlorophyll and xanthophyll.

Answer 1

Hint: Chlorophyll is a photosynthetic pigment which is an inorganic molecule that possesses magnesium ligand in its structure. Chlorophyll is not only present in a chloroplast but also found in some primitive type organisms like mesosomes of cyanobacteria. Several variants of chlorophyll are found that are named as chlorophyll a, b and c.

Complete answer: Chlorophyll is the green colour pigment that is found in the chloroplast, which is responsible for green colour and trapping the radiant energy. In algae, the chlorophyll-a pigment performs photosynthesis. Carotene is also a pigment that can trap radiant energy and convert into chemical energy. It appears to be a yellow colour. Different plant categories hold different kinds of chlorophyll variants which can show photosynthetic activity. Chlorophyll b is only found in green algae and plants, while xanthophyll occurs only on brown algae and green algae, which are Phaeophyta and Chlorophyta respectively. Chlorophyll a and carotene along with a variant of chlorophyll b is found in all algae. Chlorophyll present in the chloroplast consists of the thylakoid, stroma, nucleoid and starch granules. The thylakoid is a part where the light-dependent reaction takes place and the stroma is a region where the light-independent reaction takes place. In light-dependent reactions, the assimilatory product (ATP and NADPH) are formed, while in the dark reaction, the energy released from ATP (from during light reaction) helps to fix carbon from carbon dioxide molecules that enters via the stomata.
Hence, the correct option is C.

Note: Chloroplast is a green colour plastid. It is present on the leaves of plants, i.e. in the mesophyll cells of leaves. It has a porphyrin ring and consists of two antenna pigments called photosystem I and photosystem II.