Chromosome 20 is one of the 23 pairs of chromosomes in humans. Chromosome 20 spans around 63 million base pairs and represents between 2 and 2.5 percent of the total DNA in cells, chromosome 20 was fully sequenced in 2001 and was reported to contain over 59 million base pairs representing 99. 4% of the euchromatic DNA. Since then, due to sequencing improvements and fixes, the length of chromosome 20 has been updated to just over 63 million base pairs, identifying genes on each chromosome is an active area of genetic research. Because researchers use different approaches to genome annotation their predictions of the number of genes on each chromosome varies, in January 2017, two estimates differed by 11%, with one estimate giving 956 genes, and the other estimate giving 1,068 genes
Human chromosome 20 pair after G-banding. One is from mother, one is from father.
G-banding ideogram of human chromosome 20 in resolution 850 bphs. Band length in this diagram is proportional to base-pair length. This type of ideogram is generally used in genome browsers (e.g. Ensembl, UCSC Genome Browser).