Microbiology Practice Exam

What do we call the genetic material of bacteria, excluding the plasmids?

1. Chromosomal DNA

2. RNA

3. Plasmid DNA

4. Genomic RNA

The correct answer is: Chromosomal DNA

The genetic material of bacteria, excluding plasmids, is referred to as chromosomal DNA. This term specifically identifies the main genetic material that carries the majority of a bacterium's hereditary information and is organized into a single, circular molecule. Chromosomal DNA is essential for the replication and functioning of the bacterial cell, controlling various processes like metabolism, growth, and reproduction. In contrast, plasmids are small, circular DNA molecules that exist independently of chromosomal DNA within bacterial cells. They typically carry genes that may confer advantages, such as antibiotic resistance, but are not considered part of the core genetic material of the bacterium. RNA, on the other hand, is involved in the process of protein synthesis and is not a form of genetic material itself. Genomic RNA is associated with certain types of viruses, not bacteria, and does not describe the bacterial genetic material at all. Therefore, chromosomal DNA is the correct term for the primary genetic component of bacteria, excluding plasmids.