A Science Odyssey You Try It: DNA Workshop Title
All Wound Up

image of a chromosome and DNA wrapped around histone A single strand of DNA forms a chromosome, like the one displayed to the left. This chromosome is magnified (1000x). That's not nearly enough to show a single strand of DNA, which is only wide enough to hold about twenty atoms. So what accounts for the thickness?

The DNA is wrapped around spools of a protein called histone. The histone, in turn, forms large loops. So the DNA is much, much longer than the chromosome it makes up. The DNA of one of a fruit fly's chromosomes, for example, would be 12 times longer than the fly if it could be stretched out. That's quite amazing, especially when you consider that each of the fly's cells have four chromosomes and that each fly is made up of millions of cells!

DNA Replication

Protein Synthesis


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