A part of the cell containing DNA and RNA and responsible for growth and reproduction.

• A. Mitochondrion
• B. Ribosome
• C. Nucleus
• D. Lysosome

Answer: (C)

The main idea being tested is which cellular structure acts as the repository and command center for genetic material and cell division. The nucleus houses the cell’s DNA, the genetic blueprint, and the RNA needed for gene expression. It’s where transcription happens, and through regulating which genes are expressed and when the cell progresses through the cycle, it directs growth and reproduction. While mitochondria contain some DNA and RNA, their primary role is energy production, not coordinating the entire cell’s growth and division. Ribosomes are sites of protein synthesis, not genetic storage, and lysosomes are digestive compartments with enzymes. Therefore, the structure that best fits “containing DNA and RNA and responsible for growth and reproduction” is the nucleus.