The modern working definition of a gene is a portion (or sequence) of DNA that codes for a known cellular function or process (e.g. the function make melanin molecules). A single 'gene' is most similar to a single 'word' in the English language.
Polar covalent bonds hold the actual hydrogen and oxygen atoms within the molecule of water but if you meant what holds water together as a liquid then that is called hydrogenâ¦ bonding between molecules, a type of dipole interaction.
When two water molecules get close together, the polar forces work to draw the molecules together. The oxygen atom of one water molecule will bond with several hydrogen atoms of other water molecules. These bonds are called hydrogen bonds. Hydrogen bonds are not as strong as covalent bonds, but they are strong enough to bind water molecules together and give water its unique characteristics.