Problem:

Trace amounts of a new compound dioxin were present in, a defoliant sprayed on vegetation during the Vietnam War. Animal tests suggest that dioxin can cause birth defects, cancer, liver and thymus damage, immune system suppression, sometimes leading to death. But the animal tests are equivocal; a hamster is not affected by a dose that can kill guinea pig. dioxin acts somewhat like a steroid hormone, entering a cell and binding to a receptor protein that then attaches to the cell's DNA

Required:

Question 1: How might this mechanism help to explain the variety of dioxin's effects on different body systems and in different animals?

Question 2: How might you determine whether a type of illness is related to dioxin exposure?

Quetion 3: How might you determine whether a particular individual became ill as a result of exposure to dioxin?

Question 4: Which of the above (2 or 3) would be more difficult to demonstrate? Why?

Include source of information for best answer.