Question

Pigment which is absent in chloroplast is
A.Chlorophyll
B.Carotene
C.Xanthophyll
D.Anthocyanin

Answer 1

Hint: Chloroplast are specialised organelles that carry out photosynthesis by the help of the green pigment chlorophyll. Apart from photosynthesis chloroplast also helps in the synthesis of fatty acid, amino acid and also triggers immune responses in plants.

Complete answer:
The chloroplast comprises mostly three membrane systems- the outer chloroplast membrane, the thylakoid system and the inner chloroplast membrane. Between the inner and outer chloroplast membrane is a gel like fluid known as the stroma. The outer chloroplast membrane allows passage of small molecules and ions but not large proteins. The inner chloroplast membrane also regulates passage of materials into and outside the chloroplast. Apart from that it is also the site for synthesis of fatty acid, carotenoids and lipids. The stroma consists of the chloroplast DNA, ribosome, starch granules and many important proteins such as RuBisCO. The thylakoid system consists of small interconnected stacks where the light reaction of photosynthesis takes place. It consists of the Photosystem I and II which contain light harvesting pigments. These pigments include- chlorophyll, carotenoids, xanthophylls and phycobilins. Chlorophyll is the green pigment and consists of subtypes- chlorophyll a, b , c d and f. carotenoids are yellow-orange pigments, xanthophylls are orange-red pigments and phycobilins are of various different colours.

Hence, the correct answer is option (D)

Note: Chloroplasts are thought to be obtained by the endosymbiotic event where a cyanobacterium was engulfed by an eukaryotic organism. Chloroplasts cannot be synthesized by the plant and have to be inherited from the parent during cell division.