In DNA methylation, the most frequently methylated nitrogenous base is the cytosine. Its methylation is widespread in prokaryotes and eukaryotes. Its rate of DNA methylation differs greatly between different species like Arabidopsis thaliana which is 8%, Physarum, 4%, Mus musculus, 2.3%, and etc.
James Watson<span> and</span>Francis Crick <span> discovered the three-dimensional structure of dna in 1953</span>
Of human genome codes for protein? 1 percent
Sometimes genes change their form in a process without a reason and it's called spontaneous mutation. Spontaneous mutations<span> occur with non-zero probability. And they occur even in an uncontaminated cell. They are characterized by the specific changes.</span>