Chromosome

Definition

A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In microbes, chromosomes carry essential genes necessary for survival and reproduction.

5 Must Know Facts For Your Next Test

1. Microbial chromosomes are typically circular in bacteria but can be linear in some archaea and eukaryotic microbes.
2. Chromosomes contain genes, regulatory elements, and non-coding sequences.
3. Plasmids are separate from chromosomes but can carry additional genetic information that may provide advantages such as antibiotic resistance.
4. During binary fission, bacterial chromosomes replicate to ensure each daughter cell receives an identical copy of genetic material.
5. Horizontal gene transfer, such as transformation, transduction, and conjugation, can introduce new genetic material into microbial chromosomes.

Review Questions

• What is the primary structure of a bacterial chromosome?
• How do plasmids differ from microbial chromosomes?
• What role does horizontal gene transfer play in microbial genetics?

Related terms

Gene:

A segment of DNA that contains coding information for building proteins or functional RNA.

Plasmid:

A small, circular piece of DNA that exists independently of the chromosomal DNA in bacteria and some eukaryotic cells.

Binary Fission:

The process by which a bacterial cell divides into two identical daughter cells.