Which molecules are particles could move through a lipid bilayer without the help of some type of transport protein
1) Small molecules
2) Big molecules
3) Polar molecules
4) non-polar molecules
5) Ions
6) sugar

during the process of dna replication, brdu can replace thymidine and incorporate into the newly synthesized dna, cell proliferation thus can be reflected in the extent of brdu incorporation.

c is the correct answer hope this !