Concept 31 Some DNA does not encode protein.
Roy Britten, 1970s.
Roy Britten with his two sons and his aunt, 1970s.
Repetitive DNA can have preferred insertion sites. In this example, yellow represents the distribution of mys (a type of LINE) over a mouse genome where chromosomes are orange. There are more mys inserted in the sex (X) chromosomes.
One theory about the existence of repetitive DNA is the "selfish gene" theory. DNA sequences that replicate well will exist in more copies.
Although LINEs and SINEs both use the same type of reverse transcriptase for insertion, as a group they insert into different locations on chromosomes. Why?
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Roy Britten, 1970s.
DNA is packaged in a chromosome.
Higher cells incorporate an ancient chromosome.
Some DNA does not encode protein.
Some DNA can jump.
Genes can be turned on and off.
Genes can be moved between species.
DNA responds to signals from outside the cell.
Different genes are active in different kinds of cells.
Master genes control basic body plans.
Development balances cell growth and death.
A genome is an entire set of genes.
Living things share common genes.
DNA is only the beginning for understanding the human genome.