Question

Which photosynthetic pigment is called universal photosynthetic pigment?
A. Chlorophyll -d
B. Chlorophyll -c
C. Chlorophyll -b
D. Chlorophyll -a

Answer 1

Hint: In green plants, chlorophyll is a major light harvesting pigment. Universal photosynthetic pigment is present in all kinds of photosynthetic organisms.

Complete answer:
> Chlorophyll-d is the pigment present in specific plants like cyanobacteria and it covers very less population of it. So, it cannot be called a universal pigment.
> Chlorophyll-c is generally present in the marine algae like red and brown algae. The pigment is restricted to algae. So, it will be an inappropriate choice.
> Chlorophyll-b is present in aerobic photosynthetic organisms. Hence it does not cover the anaerobic section of plants, they are not universal pigments.
> Chlorophyll a is called universal photosynthetic pigment as it is present in all photosynthetic organisms. A photosynthetic pigment is present in chloroplasts or in photosynthetic bacteria. It captures energy from light to fulfil the purpose called photosynthesis. The major pigments present in plants are: carotene which is an orange pigment, xanthophyll which is a yellow pigment, phaeophytin which is a grey brown pigment, phaeophytin b which is a yellow brown pigment and chlorophylls which are green pigments. Chlorophyll is the major pigment which is present in each and every plant. It helps plants in photosynthesis. Each and every pigment absorbs light in different regions of the electromagnetic spectrum. Chlorophyll-a absorbs within the range of wavelength of 400-450 nm. Chlorophyll-b absorbs within the range of wavelength of 600-650 nm. Green-yellow region is the best region of spectrum, where most of the pigments get activated.
Chlorophyll-a is the most important pigment in photosynthetic organisms. It is present in all oxygenic photosynthetic organisms as well as in anaerobic bacteria like green sulphur bacteria.

So, option D is correct.

Note:
The photosynthetic pigments are the primary electron donor in the electron transport chain in eukaryotes as well as in proteobacteria. Chlorophyll-a is most abundant in nature.