<span>Are mirror images of one another
in science, an enantiomer, otherwise called an optical isomer, where you have two stereoisomers that are perfect representations of each other that are non-superimposable , much as one's left and right hands are the same aside from being turned around along one pivot.</span>
This is because the GP120 protein
of the HIV virus that forms the ‘knob’ is
essential for the infection of CD4 cells
of the immune system by the virus. The glycoprotein is, therefore, a good
target for vaccines especially since the
molecule is highly conserved because most mutations in the region could be highly deleterious to the virus.
<span>In theory, to gain a pound of body weight per
week, one must consume an additional 1,000 calories per day. An approximate
3,500 calories is equivalent to a pound of body weight. If a person
continuously consumes more than 3,500 calories over a period of time it is
expected that this person will gain 1 pound of weight. <span>
<span>Nutritionists
usually suggest that an
underweight person should add between 500-1,000 calories per day to encourage a
1-2 pound increase in body weight. Because being underweight sacrifices one's
immunity and overall health.</span></span></span>
D Because the law of superposition the younger rocks are ontop of the older rocks
