Concept 40: Living things share common genes.
All organisms store genetic information in DNA and RNA.
All living organisms store genetic information using the same molecules â€” DNA and RNA. Written in the genetic code of these molecules is compelling evidence of the shared ancestry of all living things. Evolution of higher life forms requires the development of new genes to support different body plans and types of nutrition. Even so, complex organisms retain many genes that govern core metabolic functions carried over from their primitive past. Genes are maintained over an organism's evolution, however, genes can also be exchanged or "stolen" from other organisms. Bacteria can exchange plasmids carrying antibiotic resistance genes through conjugation, and viruses can insert their genes into host cells. Some mammalian genes have also been adopted by viruses and later passed onto other mammalian hosts. Regardless of how an organism gets and retains a gene, regions essential for the correct function of the protein are always conserved. Some mutations can accumulate in non-essential regions; these mutations are an overall history of the evolutionary life of a gene.
antibiotic resistance genes, dna and rna, mammalian genes, living organisms, host cells, gene regions, metabolic functions, genetic information, genetic code, compelling evidence, organism, ancestry, bacteria, protein, evolution
- ID: 16833
- Source: DNALC.DNAFTB
Recombinant DNA technology has made it possible to test gene function in bacteria or cell cultures rather than animal models.
Model organisms share with humans many key biochemical and physiological functions that have been conserved (maintained) by evolution.
Organisms can regulate gene expression.
Mike Wigler shows how all organisms share similar genes, called homologs.
Use green fluorescent protein to tag expression of genes.
Long non-coding sequences separate relatively infrequent islands of genes in eukaryotic DNA.
Dr. Roberts describes the flow of information from DNA to RNA to protein.
DNAFTB Animation 30: Ivan Wallin presents his idea that mitochondria and chloroplasts were once free-living organisms.
Because it contains the directions for assembling the components of the cell, DNA is often thought of as the "instruction book" for assembling life.