Which organelle contains a cell's genetic material?

• A. Nucleus
• B. Rough endoplasmic reticulum
• C. Ribosome
• D. Golgi apparatus

Answer: (A)

Genetic material, in the form of DNA, is stored in the nucleus. The nucleus acts as the cell’s control center, housing the genome and regulating gene expression through transcription. The DNA is organized into chromosomes and protected by the nuclear envelope, which has pores to allow RNA to move out into the cytoplasm for protein synthesis.

Ribosomes can synthesize proteins but do not contain DNA. The rough endoplasmic reticulum is a site for protein production and modification, linked to the nucleus, but it does not store genetic material. The Golgi apparatus processes and packages proteins for transport, and likewise does not hold DNA. (Note that some organelles like mitochondria do carry their own DNA, but the nucleus is the primary repository for the cell’s genetic material and is the best answer in this context.)