A single chromosome can record a history for each gene.

In other words, there may have been many individual genes performing various functions but not yet strung together in a single chromosome.

To keep matters simple, I assume all critters have a single chromosome, that is, are haploids.

The bacterium contains a single chromosome and no known plasmids.

A haplotype is a series of linked alleles that are inherited together on a single chromosome.

Under such conditions there is often only a single chromosome present.

The large majority of prokaryotic genomes contain a single, circular chromosome.

The genomic area isolated can range from part of a single chromosome, up to several chromosomes.

In some cases the term "zygosity" is used in the context of a single chromosome.

Most bacteria have genomes in the form of a single circular chromosome.