The correct answer would be A. seal as paramecium, bacterium, and amoeba are all single-celled organisms. Thus, they cannot be an organism with tissues.
I and III.
Chargaff's law and Rosalind Franklin's discoveries
The answer is D because they speard apart or interact in all boundaries.
The same ligand can bind to different receptors causing different responses (e.g.. acetylcholine). On the other hand, different ligands binding to different receptors can produce the same cellular response (e.g. glucagon, epinephrine).
I believe that would be an open system.
