Answer:
An isotope is one of two or more forms of the same chemical element. Different isotopes of an element have the same number of protons in the nucleus, giving them the same atomic number, but a different number of neutrons giving each elemental isotope a different atomic weight.
Explanation:
pretty sure its D
True, the plasma membrane is selectively permeable and controls the various substances that are allowed into the cell and that are allowed to leave the cell.
To transport water/nutrients to upper part of the plant
