The correct option is A.
A basic solution has a high concentration of hydroxide ions more than any type of ion and that is why it is basic in nature. An acidic solution has a higher concentration of hydrogen ions and that is why it is acidic in nature. A neutral solution has equal amount of hydroxide and hydrogen ions. Solutions are usually classified as either basic or acidic based on their hydrogen ion concentration.
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.
The mechanisms of reproductive isolation prevent the reproduction of two individuals from different species. The prezygotic mechanisms disrupt the stages of reproduction before the forming of the zygote or prevent the mating at the start, and the postzygotic mechanisms affect the stages of reproduction after the forming of the zygote.
So, the first and the third example (the urchins and the grasshoppers) show the prezygotic mechanism, as the two individuals are not able to mate or form a zygote.
The second and the fourth example ( zonkey and the death of a zygote) show the working of the postzygotic mechanisms, as the zygote is formed, but it seems to be inviable, and the zonkeys are sterile, preventing the individual to reproduce.
Answer;
I think it's d,possible spread of tropical diseases.
Enzymes <em><u>act as catalysts in Chemical reaction of cells. </u></em>And they <u><em>can lower the required activiation energy for reaction in living organisms. </em></u>
