Circular Chromosomes

Definition

Circular chromosomes are a type of chromosome, typically found in prokaryotes like bacteria, where the DNA molecule is circular or ring-shaped rather than linear.

Analogy

Think of circular chromosomes as a race track. Just like how cars on a race track can go around and around without hitting a dead end, enzymes that replicate or transcribe the DNA can keep going around the circular chromosome without stopping at an end point.

Related terms

Prokaryote: A unicellular organism that lacks a nucleus and other membrane-bound organelles. Prokaryotes have circular chromosomes.

Plasmid: A small, circular piece of DNA located in the cytoplasm of many bacteria. Plasmids are separate from the bacterial chromosome and can replicate independently.

Nucleoid: The irregularly shaped region within a prokaryotic cell where the genetic material (circular chromosome) is located.