Dna damage can occur as a result of exposure to chemicals or ultraviolet radiation. This is what happens during nucleotide excision repair of damaged dna. A multienzyme complex crosses the DNA in search of distortions in the double helix, once located, the phosphate skeleton of the affected chain is cut on both sides of the altered region, a helicase eliminates the oligonucleotide resulting from digestion, the "Gap" "is filled with a DNA polymerase and a ligase.
Yes because who ever wins gets the girl
For humans, we have 19,000 protein-coding genomes. For every gene, there are 2 alleles. This means that humans have 38,000 alleles (19,000×2=38,000).