By demonstrating reflexes in headless frogs, was able to show that the spinal cord is all that is needed for reflexes to occur.

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.

on island x the species needed to adapt because they were being subject to predators which didn't inhabit island y.  

a compound light microscope is used to magnify objects in steps.  

hope it