The answer should be hydrogen
Answer:
It was the sudden appearance (over a 10my period) of many different organisms, which occurred approx 540-548 mya. ... So it can be away from sources of oxygen, preventing microorganisms from decomposing the organism.
DNA makes up our chromosomes. Chromosomes have many gene and these genes code for specific traits, like freckles, eye color, height, and even gender. The girls' mother had the gene(s) for freckles. When their mother and father reproduced and had children, the gene for freckles was passed to the girls through their mother's eggs. . They might not have received the gene for freckles. In this case, they did.
Animal cell does not have cell wall because they do not need them.
Genetic engineering is the process of using recombinant DNA (rDNA) technology to alter the genetic makeup of an organism.