Question

Mitochondria and chloroplast are- (a) semi-autonomous organelles (b) formed by division of pre existing organelles and they contain DNA but lack protein synthesising machinery Which one of the following options is correct?

• A. (b) is true but (a) is false
• B. (a) is true but (b) is false
• C. Both (a) and (b) are false
• D. Both (a) and (b) are correct

Answer 1

The Correct Option is B

To determine which option is correct regarding mitochondria and chloroplasts, let's examine the statements:

1. Mitochondria and chloroplasts are semi-autonomous organelles.
   • Mitochondria and chloroplasts have their own DNA, which is separate from the cell's nuclear DNA. This DNA allows them to replicate independently within a cell, thus making them semi-autonomous.
   • Additionally, both organelles are capable of performing some of their own protein synthesis, as they contain ribosomes that enable them to translate genetic material into proteins.

   Therefore, statement (a) is true.

2. They are formed by division of pre-existing organelles and they contain DNA but lack protein synthesizing machinery.
   • While it is true that mitochondria and chloroplasts are formed through the division of pre-existing organelles and they contain their own DNA, it is incorrect to say that they lack protein synthesizing machinery.
   • Both mitochondria and chloroplasts contain ribosomes and have the ability to produce some of their own proteins independently.

   Therefore, statement (b) is false.

Given the analysis above, the correct answer is:

(a) is true but (b) is false