In one type of dog, black spots (B) are dominant over brown spots (b) and long tails (L) are dominant over short tails (l). Use the dihybrid cross for parents with the genotypes BBLl and BbLl and determine the likelihood of offspring with the phenotype of brown spots and short tails

answer: land bridge theory. land bridge theory held that shifting portions of dry land explained the finding of identical species on different continents. plate tectonic theory eventually eliminated the land bridge theory.

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.

examples of nucleic acids are deoxyribonucleic acid (dna) and ribonucleic acid (rna).