QUESTION 21. In the following diagram, nerve cell A is commu-
nicating with nerve cell B. Identify the structures
present on the membranes of nerve cell B that
enable it to detect a message from nerve cell A.
E Nerve cell AVC
-Nerve cell B

The structures present on the membrane of nerve cell B that enable it to detect a message from nerve cell A are surface RECEPTORS.

In conclusion, the structures present on the membrane of nerve cell B that enable it to detect a message from nerve cell A are surface RECEPTORS.

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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.

nucleic acid molecules are incredibly complex, containing the code that guarantees the four different nucleotide units comprise dna, the nucleic acid of interest to the genealogist. and one of four nitrogen-containing molecules called nucleotides