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.
depends on the macromolecule. the broad category would be covalent bonds ... but there are sort of subcategories... like, proteins are joined with peptide bonds (which occur through dehydrogenation-removal of a water molecule) protein folding is also a function of hydrogen bonding.