Because an antibody is "made" relative to the antigen, but kept at low levels when you are exposed the first time ("primary immune response"). The second time you're exposed to the same antigen, memory cells recognize it and the body produces a high level of antibodies, and the level of antibodies usually remains higher for a longer time ("secondary immune response"). This is your basic immune response (primary and secondary).
This explains exactly why vaccines are effective to extremely effective.
Answer:
Geological time scale is the arrangement of major divisions of geological time into eras, periods and epochs on the time scale.
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Answer:
Water can hydrogen bond.
Explanation:
Liquids become gases once they are heated to a certain temperature. Heat is a form of energy. This change occurs when the intermolecular forces between the liquid molecules are energized enough to break. This breakage is necessary because gaseous molecules exist individually and do not interact with one another. That being said, it takes more heat to boil water because its intermolecular forces are stronger than methanes.
Intermolecular forces (IMF) are a result of partial charges on the molecular atoms that cause temporary bonds to form between molecules.
Methane is a nonpolar molecule, meaning each atom can only have slight partial charges. The strongest IMF methane participates in are London Dispersion Forces.
Water, however, is a polar molecule, with the hydrogens having strong partial positive charges and the oxygens having strong partial negative charges. This allows water to participate in a very strong IMF called hydrogen bonding. Again, because these partial charges are so strong, the water molecules can form stronger IMFs.
<u>*When molecules have stronger IMFs, they require more energy(heat) to overcome them.*</u>
Answer:
Explanation:
During aerobic cellular respiration, glucose reacts with oxygen, forming ATP that can be used by the cell. Carbon dioxide and water are created as byproducts. In cellular respiration, glucose and oxygen react to form ATP. Water and carbon dioxide are released as byproducts.
from khan academy
STI stands for Sexually transmitted infection.
