#Question id: 11548
#Unit 7. System Physiology – Animal
If a portion of the pancreas is surgically removed from a rat and the rat subsequently loses its appetite, one explanation is that the removed portion contains cells that secrete a chemical signal that somehow stimulates appetite. Given this scenario, what type of chemical signaling is occurring?
#Question id: 11549
#Unit 7. System Physiology – Animal
If a biochemist discovers a new molecule, which of the
following pieces of data would allow her to draw the conclusion that the
molecule is a steroid hormone?
I) The molecule is lipid soluble.
II) The molecule is derived from a series of steps
beginning with cholesterol.
III) The molecule acts at a target tissue some
distance from where it is produced.
IV) The molecule uses a transport protein when in an aqueous solution such as blood.
#Question id: 11550
#Unit 7. System Physiology – Animal
Which of the
following are similar in structure to cholesterol?
I) estradiol
II) insulin
III)
glucocorticoids
IV) testosterone
V) antidiuretic hormone
#Question id: 11551
#Unit 7. System Physiology – Animal
Polypeptides can have which of the following types of
effects?
I) autocrine
II) paracrine
III) endocrine
#Question id: 11552
#Unit 7. System Physiology – Animal
Which of the following are properties of steroid
hormones?
I) Steroid hormones are lipid soluble and easily cross
the phospholipid bilayer.
II) Steroid hormones usually exert their effects on target cells through membrane receptor proteins.
III) Steroid hormones act on cells close to where they
were produced.
IV) Steroid hormones regulate gene transcription by binding to intracellular receptor proteins.
#Question id: 11553
#Unit 7. System Physiology – Animal
Tadpoles must undergo a major metamorphosis to become frogs. This change includes reabsorption of the tail, growth of limbs, calcification of the skeleton, increase in rhodopsin in the eye, development of lungs, change in hemoglobin structure, and reformation of the gut from the long gut of an herbivore to the short gut of a carnivore. Amazingly, all of these changes are induced by thyroxine. What is the most likely explanation for such a wide array of effects of thyroxine?