Biology 2581B Chapter Notes - Chapter 20.3: Comparative Genomics, Noncoding Dna, Genome Size
24 Feb 2020
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Genome sequencing provides information about gene content and organization as well as information about evolutionary relationships among organisms. Comparative genomics is the field of genomics that studies similarities and differences in gene content, function and organization among genomes of different organisms. Proks have a much smaller genome size than euks. Number of genes varies for proks but the gene density is rather constant, at around 1 gene per 1000bp: thus, prokaryotes with larger genomes have more genes. Genomes of euks are larger than those of proks, and have more genes. Multicellular euks have more dna and genes than single-celled euks. No association between genome size and the number of genes or phenotypic complexity. Most of the dna in multicellular euks is noncoding, and many genes are interrupted by introns in more complex euks, the number and length of introns are greater.
