Question

Which Organelle possess DNA?

Answer 1

Organelles that posses DNA are - nucleus, mitochondria and plastids.

• Apart from having their own DNA, these organelles also have ribosomes. This indicates that they can synthesize their own proteins as per requirement.
• The two organelles mitochondria and plastids are semi-autonomous in nature. Example of plastids is chloroplast.
• Mitochondria is concerned with production of ATP and plastids is concerned with photosynthesis.
• Nucleus is central organelle of cell responsible for complete functioning of cell.

Answer 2

The nucleus and the semi-autonomous organelles possess DNA.

• DNA acts as genetic material and dictates the formation of proteins.
• The nucleus contains the DNA (80s) that directs the cell machinery to produce the required proteins.
• However, two organelles chloroplasts (unique to green plants) and mitochondria have additional genomic DNA inside them. This is 70s DNA.
• Because of this extrachromosomal DNA, these two organelles can produce their own proteins.
• This feature throws light on the sequence of evolution of prokaryotic cells and the eukaryotic organelles.