The beginning of the Cambrian Period is marked by the evolution of hard body parts such as calcium carbonate shells. ... These body parts fossilize more easily than soft tissues, and thus the fossil record becomes much more complete after their appearance.
So the DNA can be copied to make more of themselves.<span />
the skin has cells like that
The answer is 99.
Amino acids <span>contain a carboxyl group (carbon-containing) and an amino group (nitrogen containing). Proteins are made by forming peptide bonds between the carboxyl and amino group of amino acids.
</span>If a protein is made of 100 amino acids, that means there are 99 peptide bonds (because the last, 100th amino acid will not bind the next (101st) amino acid). For each peptide bond that is created, one oxygen atom and two hydrogen atoms are taken. Therefore, one water molecule is created for each peptide bond. If there are 99 peptide bonds, 99 water molecules are created.
a group of cells that are similar in function, structure and origin.
