American Academy of Professional Coders (AAPC) Practice Exam

What substance is found in the nucleus of a cell and contains genes?

1. Cytoplasm

2. Cell membrane

3. Chromosomes

4. Ribosomes

The correct answer is: Chromosomes

The correct choice is chromosomes because they are the structures located within the nucleus of a cell that contain genetic material. Each chromosome is made up of DNA, which is organized into genes—the units of heredity that carry information necessary for the development, functioning, growth, and reproduction of living organisms. In terms of the context of cell biology, the nucleus serves as the control center of the cell, housing the chromosomes and ensuring that genetic information is accurately replicated and passed on during cell division. This is essential for the continuity of genetic information across generations of cells. Cytoplasm refers to the gel-like substance that fills the cell outside the nucleus and contains various organelles but does not contain the genetic material itself. The cell membrane is the outer layer that encloses the cell, regulating what enters and exits but is not involved in storing genes. Ribosomes are the cellular structures responsible for protein synthesis and are not related to genetic material storage. Thus, among the given options, chromosomes are the correct answer as they specifically contain the genes within the nucleus.