what does this mean? "DNA is in its composition characteristic of the species from which it is derived. This can ... be demonstrated by determining the ratios in which the individual purines and pyrimidines occur There appear to exist two main groups of DNA, namely the 'A-T type,' in which adenine and thymine predominate, and the 'G-C type,' in which guanine and cytosine are the major constituents."

Which of the four major uses is predicted to change the least by 2020?

Adoctor is trying to diagnose a patient with dry skin. which of the following resources would be the most ? a magazine ad about soft skin a growth chart online articles about dry skin medical books

What is the difference between sex-linked traits and autosomal traits in humans? a. sex-linked traits can only be passed from fathers to sons, while autosomal traits can be passed on from both parents to offspring of any sex. b. sex-linked traits are passed on through the x and y chromosomes, while autosomal traits are passed on through the other 22 chromosomes. c. sex-linked traits only affect females, while autosomal traits affect both males and females. d. sex-linked traits refer to genes that are on the x and y chromosomes, while autosomal traits refer to genes on all 23 chromosomes.