Answer:
1. 2. 4. 5. 7 and 8
Step-by-step explanation:
3. False: A single stimulus can activate multiple target cells.
6. False: A ligand does not phosphorylate protein residues but can bind and activate kinase receptors resulting in conformational changes that induce intracellular phosphorylation of target protein domains.
9. False: Second messengers relay stimulus to intracellular targets. e.g calcium can act as a second messenger.