I think its the mass that changes but im not sure
The correct answer would be the fourth option. A nucleotide consists of a phosphate group, a pentose sugar, and a nitrogen containing base that are all linked together by covalent bonds. Nucleotides are the monomer units of nucleic acids and is the basic unit of the DNA.
It could possibly refer to “the small intestines absorb most of the nutrients in food, and your circulatory system passes them on to other parts of your body to store or use. Special cells help absorbed nutrients cross intestinal lining into your bloodstream” hope this helps Good luck
