A probe, which is a molecule, used to locate homologous sequences in a mixture of DNA or RNA molecules could be:
1. an ssRNA         
2. an ssDNA
3. either RNA or DNA               
4. can be ssDNA but not ssRNA

Pathophysiology is the

1. study of physiology of pathogen
2. study of normal physiology of host
3. study of altered physiology of host
4. None of the above