Question

Plastids are cytoplasmic organelles found in plant cells and in certain protists. All plastids have essentially the same structure because
(i) They have to perform the same function.
(ii) They are localised in the aerial parts of plant.
(iii) One type of plastid can differentiate into another type of plastid depending upon the cell requirements.
(iv) All plastids have to store starch, lipids and proteins.
Which of the above mentioned statement(s) is/are correct?

• A. (i) and (ii)
• B. (ii) and (iii)
• C. Only (iii)
• D. (i) and (iv)

Answer 1

Answer: (C)

Only (iii)

Plastid differentiation depends on the metabolic requirements of the cell. The chloroplasts may develop from leucoplasts and chromoplasts, which are considered end forms of plastid differentiation, may develop from either leucoplasts or chloroplasts.

Proplastids can differentiate into one of three types of plastids and since, in certain cases, one type of plastid can differentiate into another, it has been generally assumed that all plastids are essentially the same in structure, having the ability to differentiate in various ways, depending upon the requirements of the cells.