<span>The answer is A. Variation in gene pool
Speciation is a formation of a new species during the evolution line.
When there is a variation in a gene pool, a unique combination between genes could be formed during the mating process. This will create an offspring with unique gene pool that will lead to speciation</span>
There are 4 nitrogenous bases in DNA. Adenine pairs with thymine, and Guanine pairs with cytosine. A Dna Nucleotide consists of a 5 carbon sugar, a phosphate group and a nitrogenous base. These bases are paired up by weak hydrogen bonds, so when they have have to replicate, the enzyme helicase can easily unzip the Dna. <span />
I believe that the answer is B.
Within a single water molecule.. H2O.. The hydrogens are bonded to the oxygen covaently.
Between water molecules.. as in a water droplet.. the molecules are held together by hydrogen bonds between them..