In Jonathan Wendel's Iowa State University lab, students and researchers study the strange difference in the size of different cotton genomes. Why would one cotton genome be bigger than another?
One reason that the ArabidopsisThe first plant to have its genome completely sequenced and mapped. A member of the mustard family, Arabidopsis thaliana, more commonly known as “mouse-eared cress” is a fast growing weed used in countless biological research facilities because of it relatively small and simple genome. plant was sequenced first was that its relatively simple genome contains very small amounts of highly repetitive DNADeoxyribonucleic acid; The ladder-like molecule that encodes genetic information, in the form of a double helix held together by bonds between base pairs. By using Arabidopsis as a comparison, genome scientists can start to find the genes (and the other parts of the genome that are not genes) that may have other functions.
Some say that this extra DNA is like padding an instruction manual with gossip magazines. It has more information, but the information is useless! But is it really? Or does it have information we just don't understand right now?
Plants like cotton and potatoes have lots of mystery DNA of unknown function because at some point in their evolutionThe process of change in the inherited traits of organisms from one generation to the next. This change is driven by natural selection. their genomes duplicated-doubling in size! They once had two sets of chromosomes, one from the mother and one from the father. Now, they have four.
Scientists don't completely understand why this happened, but many think that this duplication gives plants advantages. They simply have more genetic material to choose from.
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