Question

Which of the following statements about mitochondria is wrong?

• A. They have their own DNA which can replicate independently
• B. Mitochondrial matrix possesses its own ribosomes
• C. They do not synthesize any proteins
• D. Mitochondria divide similarway as prokaryotic binary fission

Hint:

Mitochondria are semi-autonomous because they synthesize some of their own proteins, while relying on the nuclear genome for others.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Mitochondria are semi-autonomous double-membrane-bound organelles. Under the endosymbiotic theory, they evolved from engulfed aerobic prokaryotes, retaining several bacterial characteristics.

Step 2: Detailed Explanation:
- (A) is correct because mitochondria contain their own circular DNA (mtDNA) that replicates independently of the nuclear genome.
- (B) is correct because the mitochondrial matrix contains ribosomes, which resemble prokaryotic 70S ribosomes rather than eukaryotic 80S ribosomes.
- (C) is incorrect because mitochondria possess all the components necessary for translation, including tRNAs and ribosomal machinery.
They actively synthesize several essential proteins encoded by their mtDNA, such as subunits of the electron transport chain complexes.
- (D) is correct because mitochondria divide within host cells via binary fission, a process homologous to bacterial division.

Step 3: Final Answer:
The incorrect statement is that mitochondria do not synthesize any proteins.