The ability of certain specifically shaped molecules to attach to a cell is primarily determined by the... 1. Receptor molecules in the cell membrane
2. Amount of DNA in a cell
3. The cytoplasm of the cell
4. Concentration of salts outside the cell

Of seawater increases with decrease in the temperature. therefore, the cold water sinks to the deeper layers at the bottom

What molecules will be best used to compare different species with the exact same sequence of amino acids? why would two species have the same protein even if the molecules in question is different? (hint: transcription to translation to protein).

What do isotopes of uranium have the same number of? what do they have a different number of? a) same number of protons; different number of electrons b) same number of protons; different number of neutrons c) same number of electrons; different number of protons d) same number of neutrons; different number of protons