Their bodies taper to points at both the snout and the tail, reducing water resistance. Also decreasing drag -- and therefore noise -- are dermal denticles, sharp scales that cover the skin of most shark species. Rather than bone, sharks have cartilage, which is much lighter and more flexible. In addition, their livers produce squalene, a fatty oil that helps them remain afloat. Their pectoral fins allow them to quickly change direction, dive and swim upward.
http://animals.mom.me/unique-adaptations-sharks-survive-7845.html
Initially, when scientists were first using the taxonomy system to classify living organisms there were only considered to be 2 kingdoms: plants and animals. However, when the microscope was invented, scientists were able to observe differences in organisms at the cellular level! They were also able to observe microscopic living organisms like bacteria that they had not been able to observe before. Scientists realized it was necessary to add 4 new kingdoms to account for the observations they had not seen before the invention of the microscope.
Answer:
the answer to that question is
fungi
Hard, dense bone tissue that is beneath the outer membrane of bone <span />
Each population of a species have different genes.
