Individuals being treated for cancer may develop nausea when they arrive at the place where they have been receiving chemotherapy. in this case, the unconditioned stimulus is : chemotherapy. nausea. the place where therapy takes place. the sound of the nurse's voice.

In this case, the unconditioned stimulus is; Chemotherapy.  

Cancer are group of diseases caused by rapid growth of abnormal cells in the body. Chemotherapy is a treatment that involves the use of medications (anti-cancer drugs) to treat cancer. Chemotherapy causes various side-effects (as a result of the damage of normal cells of the body that rapidly increase). Nausea with vomiting, are common side effects that is usually experienced by cancer patients that are receiving chemotherapy.  

i'm guessing this is from edg enuity so the answers would be, from top to bottom,

theodor schwann

matthias schleiden

robert hooke

rudolph virchow

anton van leeuwenhoek