Proteins are composed of chains of which are joined together with peptide bonds.
a) fatty acids
b) amino acids
c) nucleic acids
d) monosaccharides

The answer is B amino acids because it is composed of amino acids.

Explanation:

correct answer is option a.

tropopause, stratopause and mesopause have all in common aspect that is point of maximum temperature in its layer of the atmosphere. all layers of atmosphere observe abrupt change in temperature. tropopause is the boundary between troposphere and stratosphere. stratopause is the boundary between stratosphere and mesosphere. mesopause is the boundary between mesosphere and thermosphere. these all boundaries are ranges between altitude of 0 to 80 km.

colors do exist. the color of the sky is actually violet; humans percieve the color of the sky as blue.