The meristematic tissues is responsible for growth in angiosperms.
The answer should be proteins. Because the protein is consists of different kinds of amino acids(usually 20 in total). And our cell can not produce essential amino acids itself.
<span>They must be able to breed and produce fertile offspring.</span>
Mass number is just a count of the number of nucleons in an atomic nucleus. Atomic Mass is the actual mass of a given nucleus.
