Question

What are plastids?
(a)Energy reservoirs
(b)Replication site for DNA
(c)Synthesis of proteins and ribosomes
(d)Houses various pigments used in photosynthesis.

Answer 1

Hint: The organelle said to be developed from the endosymbiosis that means a heterotrophic protist engulfed the cyanobacteria but it does not digest it and later it is used for storage.

Complete answer:
Plastids are double-membrane small cell organelle found in the cells of plants and algae. They are the site of production and storage of important chemical compounds that are used by the cells of autotrophic organisms.
They often contain pigments that are used in photosynthesis and the types of pigments present can change or determine the color of the cell. These pigments are:
Chloroplasts – they are the green plastids that contain chlorophyll pigments for photosynthesis. They are biconvex shaped, semi-porous, double membraned, permeable cell organelle found within the mesophyll of the plant cell.
Chromoplasts – they are the colored plastids which give different color to fruits and flowers.
Leucoplasts – are the colorless plastids used for the storage of starch in plant cells. They have no pigment and are therefore white in color. The leucoplasts are of three types :
Amyloplasts – stores starch.
Proteinoplasts – stores proteins.
Elaioplasts – stores fats and oils.
Gerontoplasts – they are the chloroplasts that are going through the aging process where no photosynthesis occurs.
So, the correct answer is Houses various pigments used in photosynthesis.

Note: Plastids were discovered and named by Ernst Haeckel, but its clear definition was first provided by A.F. W. Schimper. The term plastid is derived from the Greek word ‘plastics' meaning formed. They are commonly called the ‘kitchen of the cell’.