Question

The chloroplasts of plant cells contain the primary pigment chlorophyll a. They also contain other pigments such as chlorophyll b and carotenoids. What is the purpose of these other pigments?
A) To excite electrons
B) To produce ATP
C) To produce glucose
D) To absorb water
E) To absorb different wavelengths of light

Answer 1

Chloroplasts are the molecules that are present in the green parts of the plant. It contains the photosynthetic pigments which are involved in the trapping of light falling on it. Different parts of the chloroplasts are involved in the synthesis of sugar.

Complete answer:
Photosynthesis is the process in which water and carbon dioxide is converted into sugar in the presence of sunlight. Oxygen is released in this process. It is an essential process as it serves as the primary food for all living organisms. Also, it adds oxygen to the atmosphere.

The process of photosynthesis takes place in the chloroplast of leaves or other green parts of the plant. The chloroplasts contain mainly four photosynthetic pigments. These are- chlorophyll a, chlorophyll b, xanthophylls and carotenoids.

Chlorophyll a is the primary pigment that absorbs most of the light energy. It can absorb blue and red wavelengths of light. Chlorophyll a is present in all organisms in which photosynthesis occurs.
Chlorophyll b, xanthophylls and carotenoids absorb the wider range of wavelengths of light and transfer the absorbed energy to chlorophyll a. Hence, they are called accessory pigments. These pigments also protect the chlorophyll from photo-oxidation.

Thus the answer to the above question is to absorb different wavelengths of light, as they are the accessory pigments that help in trapping most of the light energy for photosynthesis.

Thus the correct answer is option ‘E’.

Note: Grana, stroma and stroma lamellae are different regions of a chloroplast. The membrane of the chloroplast helps in the trapping of light energy and synthesis of ATP and NADPH. In stroma different reactions occur in the presence of enzymes which results in the formation of sugar.