Scientists set out to test the hypothesis that the herbicide atrazine is an endocrine disruptor that feminizes male amphibians. They treated male amphibians with atrazine and then compared their circulating testosterone concentration with those of males and females that were not treated with atrazine (controls). The results are shown here (* signifies P<0.05). Was the hypothesis supported? Why or why not?

Suppose that during a detailed anatomical study of a marine invertebrate, you found a small, previously undescribed structure. How would you test the hypothesis that the structure is a gland that releases one or more hormones?

Design a study to test the hypothesis that the symptoms of jet lag are caused by disruption of normal daily cortisol rhythms.

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Ecotourism helps conserve wildlife by increasing the value of wildlife conservation for local people. In Argentina, the world’s largest breeding colony of Magellanic penguins is visited by thousands of tourists every year, causing the penguins to become habituated to the presence of people. Has ecotourism affected the penguins’ ability to respond to stressors? Has it affected the penguins’ secretion of corticosterone?

If penguins in a colony are habituated to the presence of tourists, how would their corticosterone response to being visited by tourists compare to that of penguins in a colony not previously exposed to tourists?

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Ecotourism helps conserve wildlife by increasing the value of wildlife conservation for local people. In Argentina, the world’s largest breeding colony of Magellanic penguins is visited by thousands of tourists every year, causing the penguins to become habituated to the presence of people. Has ecotourism affected the penguins’ ability to respond to stressors? Has it affected the penguins’ secretion of corticosterone?

In what part(s) of a target cell would you expect to find corticosterone receptors?

Compare and contrast the structure and function of the anterior and posterior pituitary glands.

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Ecotourism helps conserve wildlife by increasing the value of wildlife conservation for local people. In Argentina, the world’s largest breeding colony of Magellanic penguins is visited by thousands of tourists every year, causing the penguins to become habituated to the presence of people. Has ecotourism affected the penguins’ ability to respond to stressors? Has it affected the penguins’ secretion of corticosterone?

Corticosterone is a(n):

a. Neurohormone

b. Steroid hormone

c. Amino-acid-derived hormone

d. Polypeptide hormone