Over the last several decades, the scientific community has gathered a large amount of information regarding genetics and genetic variation. What is a main source that leads to increased genetic variation?

the answer is Recombination :)

Explanation:

(i just took the test so i know its right)

not sure if this what   you'r looking for would be percent composition

water is a polar molecule. a chemical bond is a force of attraction between atoms or ions. bonds form when atoms share or transfer valence electrons. atoms form chemical bonds to achieve a full outer energy level, which is the most stable arrangement of electrons. so, false

explanation:

in h2o molecule, two water molecules are bonded by a hydrogen bond but the bond between two h - o bonds within a water molecule are covalent. the greater the electronegativity difference, the more ionic the bond is. bonds that are partly ionic are called polar covalent bonds. nonpolar covalent bonds, with equal sharing of the bond electrons, arise when the electronegativities of the two atoms are equal.