What part of the cell contains DNA and RNA and is crucial for growth and reproduction?

The nucleus is the part of the cell that contains both DNA and RNA, playing a crucial role in the growth and reproduction of the cell. It serves as the control center, housing the cell's genetic material (DNA), which contains the instructions for building and maintaining the organism. The presence of RNA within the nucleus is essential as well, as it is responsible for translating the DNA code into proteins, which are vital for various cellular functions.

Mitochondria, while essential for energy production and cellular respiration, do not contain DNA in the same sense as the nucleus. They have their own small circular DNA, but it is mainly involved in the energy production process rather than the overall genetic information of the cell. The cytoplasm, on the other hand, is the cellular fluid that supports the organelles, and ribosomes are responsible for synthesizing proteins based on the RNA instructions, but neither of these structures contains DNA or RNA as their primary function. Thus, the nucleus stands out as the central organelle for managing growth and reproduction through its genetic material.