The biological species concept is least relevant to which of the following groups of organisms?
a. Birds Mammals that form monogamous pair bonds
b. Asexual fungi
c. Fungi that engage in sexual reproduction
d. Cryptic species

Explanation:

The biological species concept defines a species as a group of individuals living in one or more populations that can potentially interbreed to produce healthy, fertile offspring

Hence it includes the groups which are reproductively isolated so asexual fungi will be least relevant to this group

this is true, assuming that the allele is completely recessive and incomplete dominance is not a factor.

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.