Answer:
We only know it's there because we can see the effect of its gravity. Scientists study dark matter by looking at the effects it has on visible objects. Scientists believe that dark matter may account for the unexplained motions of stars within galaxies. Computers play an important role in the search for dark matter information.
Explanation:
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The structures a virus can contain are
-nucleic acid
-envelope
-capsid
Leptin
Leptin is a hormone produced by the adipose
tissue of the human body. It is made up of 167 amino acids and it performs its
key role in the regulation of body weight, energy balance and endocrine
function. However, deficiency if leptin and its receptor in human will result in
obesity.