Hormones are specific. explain how a receptor results in the cell being able to respond to only one specific hormone.

This is because the active site of the receptors on the cell and the hormone are akin to lock and key respectively. The conformations of the receptor’s active site and the hormone allow them to interlock with specificity. The receptor (which is a transmembrane protein) is connected to second messengers inside of the cell that triggers a biochemical cascade in response to the hormone.

the relative atomic mass of an element is the mass of one atom of that element, relative to 1/12th of the mass of a  1212c atom. to convert to an absolute mass in kg, it is necessary to multiply by  1.661×10−271.661×10−27.

the relative atomic mass is roughly equal to the number of neutrons, plus the number of protons, in the nucleus of the atom.

for elements with more than one stable isotope (different types of nucleus with different numbers of neutrons but the same number of protons), the quoted mass is usually the average mass, weighted by the relative abundance of the different isotopes.

feral cats are estimated to eat tens of millions of native animals each night in australia