Map Units. Map units don't technically measure a distance, but rather the probability of a split in the chromosome between two loci. But the probability and distance are directly proportional. I don't know of any other term you might use.
Source:AP Bio Student
The term that defines the distance between two genes on a single chromosome is "genetic linkage." This distance is measured in units called centimorgans, and genetic linkage helps scientists understand how close or far apart genes are from each other on a chromosome.
The number varies greatly between species.
In late anaphase and G1 of interphase, a chromosome is unreplicated and consists of a single DNA double helix. A replicated chromosome contains two identical DNA double helices.
Single
A single arm of a chromosome is called a chromatid. During cell division, each chromosome consists of two sister chromatids that are joined together at a region called the centromere.
No, some bacteria and other unicellular organisms have a single chromosome
A chromosome is formed from a single DNA molecule.
A Chromatid is a single section or "half" of the intended Chromosome. It contains half of the genetic material of a full Chromosome. Two Chromatids are generally bound together with a Centromere in order to form a fully functional X Chromosome.
CODON
The single chromosome mass found in bacteria is called a "nucleoid." Unlike eukaryotic cells, bacteria typically have a single circular chromosome that contains their genetic material, which is not enclosed within a membrane-bound nucleus. The nucleoid region is where this chromosome is located, along with associated proteins that help organize and condense the DNA.
You have about 20,000 to 25,000 genes in 23 chromosomes in human cell. So approximately 1000 genes are there in any single chromosome. The gene will be too big in size, if you have one single gene in any single chromosome.
The difference between a chromosome and a DNA molecule is that a chromosome is a single DNA molecule associated with proteins and a DNA molecule is a long thin molecule that stores genetic information.