Deck 47: Chemical Signals in Animals

Question 1

Polypeptides can have which of the following types of effects?

A)autocrine
B)paracrine
C)endocrine
D)all of the above

Answer 1

D

Question 2

You are dissecting a fish in your biology laboratory section.Your teaching assistant points out a long oval structure and tells you it is an endocrine gland.Which of the following would you then know is a true statement about this structure?

A)It secretes a product that is carried in the bloodstream or other fluids to target cells.
B)The gland's product will only interact with receptors on the cell membrane.
C)The gland's product is lipid soluble.
D)The gland produces and secretes its product.

Answer 2

D

Question 3

People with type II diabetes mellitus have defective insulin receptors that cannot respond to insulin properly.Relative to normal individuals,what would be the effect on blood glucose levels of chronic stress that kept blood cortisol levels high?

A)There would be a greater increase in blood glucose levels in individuals with type II diabetes mellitus than in normal individuals.
B)There would be less increase in blood glucose levels in individuals with type II diabetes mellitus than in normal individuals.
C)There would be a greater decrease in blood glucose levels in individuals with type II diabetes mellitus than in normal individuals.
D)There would be less decrease in blood glucose levels in individuals with type II diabetes mellitus than in normal individuals.
E)There would be about the same effect on blood glucose levels in both types of individuals.

Answer 3

B

Question 4

Which of the following is similar in structure to cholesterol?

A)leptin and serotonin
B)luteinizing hormone and insulin
C)melanocyte-stimulating hormone and vasopressin
D)testosterone,estradiol,and cortisol
E)oxytocin and vasopressin

Question 5

Removing which of the following glands would have the most wide-reaching effect on bodily functions of an adult human?

A)adrenal glands
B)pituitary gland
C)thyroid gland
D)ovaries (in female)or testes (in male)

Question 6

In experiments where researchers suspect that a hormone may be responsible for a certain physiological effect,they may cut the neurons leading to the organ where the effect being studied occurs.What is the purpose of cutting these neurons?

A)to make sure that the effect is not occurring through actions in the nervous system
B)to make sure that the organ being affected cannot function unless the researchers stimulate it with an external electrical probe
C)to impair the normal functions of the organ so that the hormonal effect can be more easily studied
D)to numb the organ so that it can be probed without inducing pain in the lab animal

Question 7

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?

A)autocrine
B)paracrine
C)endocrine
D)neuroendocrine

Question 8

The regulation of blood sugar levels and our stress responses are controlled in part by a negative feedback loop involving cortisol,ACTH,and CRH.What would likely be the result during times of stress if cortisol receptors in the hypothalamus were nonfunctional?

A)Blood sugar levels would rise to dangerous levels.
B)Blood sugar levels would be unaffected.
C)ACTH production would cease.
D)CRH production would cease.
E)Cortisol production would cease.

Question 9

When a person drinks alcohol the rate of urination increases.This suggests that antidiuretic hormone (ADH)may be affected by alcohol consumption in some way.Which of the following could account for the increase in urination?

A)Alcohol stimulates the release of ADH.
B)Alcohol inhibits the release of ADH.
C)Alcohol inhibits the binding of ADH to receptors in the nephron.
D)Alcohol could inhibit ADH release or the binding of ADH to receptors in the nephron.

Question 10

A cluster of tumor cells that produces and secretes growth factors to induce surrounding cells to grow and divide are showing which type of cell-to-cell signaling?

A)autocrine
B)paracrine
C)endocrine
D)neuroendocrine

Question 11

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?

A)The molecule is lipid soluble.
B)The molecule is derived from a series of steps beginning with cholesterol.
C)The molecule acts at a target tissue some distance from where it is produced.
D)The molecule uses a carrier protein when in an aqueous solution such as blood.
E)All of the above would indicate this molecule is a steroid hormone.

Question 12

Which of these glands is located within the abdominal cavity?

A)thyroid
B)adrenal
C)parathyroid
D)pancreas
E)all of the above

Question 13

Osteoporosis is a condition in which the density of bones is decreased so much that the individual is at a higher risk of fractures.The more calcium in the bones,the better the bone density.Which of the following would have the greatest effect on calcium levels in the bones?

A)calcitonin injection
B)calcitonin receptor blocker
C)parathyroid hormone injection
D)parathyroid receptor blocker

Question 14

All of the following are examples of amplification of a hormone signal except _____.

A)epinephrine initiates an enzyme cascade
B)steroids bind hormone-response elements in the cell and initiate gene transcription
C)0)09 mg of growth hormone leads to a 10,000-mg weight gain in a cow
D)different cell types have different receptors capable of binding the same hormone

Question 15

In human embryonic development,which of the following pairs of hormones are released by the developing testes and result in development of the male reproductive tract and inhibition of the female reproductive tract?

A)testosterone and estrogen
B)estrogen and progesterone
C)testosterone and Mullerian inhibitory substance
D)estradiol and estrogen
E)testosterone and estradiol

Question 16

Predict the effects of a drug that increases adrenocorticotropic hormone (ACTH)synthesis.

A)increase in glucocorticoid production
B)increase in release of corticotropin-releasing hormone (CRH)
C)decrease in cortisol release
D)decrease in release of corticotropin-releasing hormone (CRH)
E)all of the above

Question 17

When partially digested food enters the small intestine from the stomach,several events must occur to protect the intestine and allow for the continued digestion of the food.One hormone in particular performs two of these functions.What intestinal hormone is responsible for causing the pancreas to release digestive enzymes and the gallbladder to release bile salts into the intestine?

A)secretin
B)cholecystokinin
C)insulin
D)epinephrine
E)corticosterone

Question 18

You have three strains of mice:
A,B,and C.You experimentally manipulate each strain and find that all three show increased secretion of molecule X.Now you perform a parabiosis experiment with the three combinations of these mice:
AB,AC,and BC.You perform the same experimental manipulation as above on one mouse of each pair without directly affecting the other mouse and look for effects on the other mouse.You find no detectable effect on the unmanipulated partner in any of the combinations.What is the logical conclusion based on these results?

A)The effect on molecule X is not mediated by hormones.
B)The effect on molecule X is not mediated by nerves.
C)The effect on molecule X was just an artifact of the first experiment.
D)The effect on molecule X is controlled by higher integrative centers of the brain.

Question 19

What property of the steroid hormones allows them to cross the phospholipid bilayer?

A)Steroid hormones are lipid soluble and easily cross the phospholipid bilayer.
B)Steroid hormones can act in very small concentrations and very few molecules of steroids need to cross the lipid bilayer.
C)Steroid hormones act on cells close to where they were produced and very few molecules are required to travel such a short distance to cross the lipid bilayer.
D)Steroid hormones act on the same cells in which they are produced and therefore are within the cell they are acting upon.
E)None of the above are true.

Question 20

What is the only type of chemical signal that is not intended to alter the physiology of the animal producing that signal?

A)neural
B)paracrine
C)neuroendocrine
D)pheromones
E)only neural and neuroendocrine signals

Question 21

How are small amounts of hormones amplified?

A)One cAMP molecule stimulates one cAMP-dependent protein kinase A molecule,which activates many molecules of phosphorylase kinase.
B)One cAMP molecule triggers the production of more hormone.
C)One cAMP molecule stimulates several cAMP-dependent protein kinase A molecules,which activates many molecules of phosphorylase kinase.
D)Signal transduction cascades are dependent upon second messenger signaling only in rare cases and only when the hormone in question is a steroid.

Question 22

Prolactin tumors can cause a number of effects on the body.Which of the following might occur in a male patient?

A)acromegaly - the enlargement of the hands,feet,and jaw
B)excessive fat buildup in the face,neck,and abdomen
C)increase in heart rate
D)lactation
E)weight loss

Question 23

Which of the following best describes the neuroendocrine-to-endocrine pathway of hormone action?

A)a neural organ that produces hormones regulates another gland through the release of hormones into the circulation that travel to the affected gland
B)a neural organ that produces hormones releases its hormones directly into another gland that it regulates
C)a gland that releases hormones directly into a neural structure,thus regulating neural functions
D)a gland that exhibits negative feedback on the nervous system by releasing hormones into neural tissue both directly and indirectly through the circulation

Question 24

Which of the following hormone does not act via a second messenger system?

A)insulin
B)norepinephrine
C)growth hormone
D)estrogen
E)ACTH

Question 25

Which of the following hormones does not act using a second messenger system?

A)glucagon
B)leptin
C)testosterone
D)growth hormone

Question 26

When adenylyl cyclase is activated ________.

A)cAMP is created
B)cAMP is destroyed
C)G-proteins bind to cAMP
D)steroid hormones pass through the lipid bilayer

Question 27

Signal transduction occurs when a chemical message at the cell surface elicits a response inside the cell.Which one of the following events is not associated with signal transduction?

A)protein phosphorylation
B)cell-surface receptor binding
C)internal receptor binding
D)second messenger activation

Question 28

Of the following types of molecules,which can function as both neurotransmitters and hormones?

A)glucocorticoids
B)second messengers
C)catecholamines
D)adipocytes

Question 29

Which of the following is true during a typical cAMP-type signal transduction event?

A)The second messenger is the last part of the system to be activated.
B)The hormone activates the second messenger by directly binding to it.
C)The second messenger amplifies the hormonal response by attracting more hormones to the cell being affected.
D)Adenylyl cyclase is activated after the hormone binds to the cell and before phosphorylation occurs.

Question 30

Patients diagnosed with hypercortisolism may have tumors that secrete _____.

A)growth hormone
B)ACTH
C)estrogen
D)leptin

Question 31

Glucocorticoids do which of the following?

A)promote the immune response
B)promote the release of fatty acids
C)increase blood glucose levels
D)increase insulin production

Question 32

Which of the following statements correctly describes the relationship between the hypothalamus (H)and the anterior (AP)and posterior (PP)lobes of the pituitary?

A)The H is the neural system that releases hormones directly into the AP and communicates with the PP only through the circulation.
B)The AP regulates the H through negative feedback mechanisms while the PP regulates the H through positive feedback.
C)The H communicates directly with the PP and indirectly with the AP through the circulatory system.
D)The H regulates secretions from the PP,which then regulates all secretions from the AP.

Question 33

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?

A)There are many different forms of thyroxine,each specific to a different tissue.
B)Different tissues have different types of receptors.
C)Some tissues have membrane receptors for thyroxine,while other tissues have thyroxine receptors within the nucleus.
D)Different releasing hormones release thyroxine to different tissues.