<span>Dinosaurs were common in the Jurassic period, but during the Cretaceous period they went extinct. Pangaea had fully split by the Cretaceous period and angiosperms had developed. Hope this answers the question. Have a nice day. Feel free to ask more questions.</span>
I think the cauae of substitution they involve swapping of one nucleotide for another during DNA repliction.For example,during repliction,a thymine nucleotide might be inserted in placed of a guanine nucleotide
Researchers found that chronic exposure to a stress hormone causes modifications to DNA in the brains of mice, prompting changes in gene expression. The new finding provides clues into how chronic stress might affect human behavior.
