Which organelle contains genetic material and controls cellular activities?

• A. Mitochondria
• B. Nucleus
• C. Ribosome
• D. Golgi apparatus

Answer: (B)

Genetic information storage and cellular regulation are centered in the nucleus. The nucleus houses most of the cell’s DNA, organized into chromosomes, and it acts as the command center by controlling which genes are turned on or off and when. This control happens through transcription of DNA into RNA and via the nuclear processes that assemble ribosomes and coordinate gene expression. The nuclear envelope with pores manages traffic between the nucleus and the rest of the cell, keeping the genetic material protected while allowing necessary messages to move out to direct cellular activities.

Other organelles have important roles but don’t serve as the primary repository for genetic information or the overall controller of the cell. Mitochondria contain a small amount of DNA and are essential for energy production and programmed cell death, but they don’t direct the cell’s activities like the nucleus does. Ribosomes are the sites of protein synthesis but don’t contain DNA, and the Golgi apparatus modifies and ships proteins without storing genetic material.