Isotopes are variants of a particular chemical element which differ in neutron number, although all isotopes of a given element have the same number of protons in each atom. The term isotope is formed from the Greek roots isos and topos, meaning "the same place"; thus, the meaning behind the name is that different isotopes of a single element occupy the same position on the periodic table.
Answer:
Aquaporins
Explanation:
Aquaporins are the channel proteins that is present in the membrane of the cell which allow water to cross the membrane very quickly. This aquaporins play an important roles in plant cells, red blood cells, and certain parts of the kidney where this protein minimize the amount of water lost as urine. Without this protein, the diffusion of water across the cell membrane is not possible very quickly.
Crossing over. Parts of sister chromatids will sometimes switch places with the parallel part, resulting in a completely unique DNA sequence.