https://www.genome.gov/10001485/2000-release-chromosome-21-sequenced
Down Syndrome Research Expedited by Decoding of Human Chromosome 21 - Second Human Chromosome...
down syndrome researchhuman chromosome 21expedited
https://www.ncbi.nlm.nih.gov/nuccore/NC_007132.6
Danio rerio strain Tuebingen chromosome 21, GRCz10 - Nucleotide - NCBI
danio reriochromosome 21straintuebingengrcz10
https://medlineplus.gov/genetics/chromosome/21/
Chromosome 21: MedlinePlus Genetics
Chromosome 21 is the smallest human chromosome, spanning about 48 million base pairs (the building blocks of DNA) and representing 1.5 to 2 percent of the...
chromosome 21medlineplusgenetics
https://www.genome.gov/25520477/online-education-kit-2000-chromosome-21
2000: Chromosome 21
2000chromosome21