Answer:
A. ponds are shallower than lakes
Explanation:
Ponds are not larger than lakes.
Pond water may move more than lakes in some situations, but it is not a defininte.
Lakes don't always have more vegetation than ponds.
Answer:
C. antigen-antibody reactions
Explanation:
human blood group is determined by the presence of antigens on the red blood cells which are specific proteins.
so specific antibodies are used against these antigens to determine the type of blood group after the reaction.
Answer:
Scientists believe that the different types we know emerged as early humans adapted to infectious diseases.
Explanation:
Different human blood types probably emerged to ward off infectious diseases. The incompatibility of some blood types, however, is only an "accident" of evolution. But this is a relatively recent problem, since blood transfusion has been around for only a few hundred years.
There are four main blood types. The oldest is B, which must have originated about 3.5 million years ago - it existed even before the human species evolved from its hominid ancestors, from a genetic mutation that modified one of the sugars in the surface of red blood cells.
Approximately 2.5 million years ago, mutations inactivated sugar, resulting in type O blood, which has neither type A nor B. sugar. AB blood, as it is easy to suppose, is covered by both sugar A and sugar by B.
Human activities contribute to climate change by causing changes in Earth's atmosphere in the amounts of greenhouse gases, aerosols (small particles), and cloudiness. The largest known contribution comes from the burning of fossil fuels, which releases carbon dioxide gas to the atmosphere.
