Answer and explanation;
-Aba is a suitable replacement because Aba and Cys have approximately the same sized side chain and are similarly hydrophobic.
-However, Aba cannot form disulfide bonds so it will not be a suitable replacement if these are required.
-Alpha-Aminobutyric acid is biosynthesized by transaminating oxobutyrate, a metabolite in isoleucine biosynthesis.
<span>The correct answer is d. the idea that T. rex held its tail aloft was supported by the studies of many scientists. This is how science works, things are discovered by having members of the scientific community do experiments and come to the same conclusion. Many of them confirmed this theory and a concensus was established.</span>
A control group is important for an experiment because it allows the experiment to minimize the changes in all other variables except the one being tested.