Introduction:
There are two organelles in a cell that contain their own genetic material, known as DNA. These organelles are the nucleus and the mitochondria. Both of these organelles play crucial roles in the functioning of the cell and have distinct characteristics.

Nucleus:
The nucleus is often referred to as the control center of the cell as it contains the genetic material, DNA. The DNA carries the instructions necessary for the development, growth, and functioning of the cell. It is enclosed within a double membrane called the nuclear envelope, which has nuclear pores that allow the movement of certain molecules in and out of the nucleus. The DNA is organized into structures called chromosomes, which become visible during cell division.

Mitochondria:
Mitochondria are often referred to as the powerhouses of the cell. They are responsible for generating energy through a process called cellular respiration. Mitochondria contain their own DNA, known as mitochondrial DNA (mtDNA). Unlike nuclear DNA, which is inherited from both parents, mtDNA is exclusively inherited from the mother. Mitochondrial DNA contains genes that code for proteins involved in energy production.

Comparison:
Nucleus:
- Contains the majority of the cell's genetic material.
- Enclosed within a double membrane.
- DNA is organized into chromosomes.
- Inherited from both parents.
- Controls the overall functioning of the cell.

Mitochondria:
- Contains a small amount of genetic material.
- Surrounded by a double membrane.
- DNA is circular and not organized into chromosomes.
- Inherited exclusively from the mother.
- Responsible for energy production.

Conclusion:
In conclusion, the nucleus and mitochondria are the two organelles that contain their own genetic material. The nucleus contains the majority of the cell's DNA and is responsible for controlling the overall functioning of the cell. On the other hand, mitochondria contain a small amount of DNA and are involved in energy production. Understanding the roles and characteristics of these organelles is crucial in comprehending the complex workings of a cell.