06 Flashcards
Which of the following statements about hormones is incorrect?
A) They are produced by endocrine glands.
B) They are modified amino acids, peptides, or steroid molecules.
C) They are carried by the circulatory system.
D) They are used to communicate between different organisms.
E) They elicit specific biological responses from target cells.
D) They are used to communicate between different organisms.
The secretion of hormone A causes a change in the amount of protein X in an organism. If this mechanism works by positive feedback, which of the following statements represents that fact?
A) An increase in A produces an increase in X.
B) An increase in X produces a decrease in A.
C) A decrease in A produces an increase in X.
D) A and B are correct.
E) B and C are correct.
A) An increase in A produces an increase in X.
Which of the following is (are) true?
A) Hormones regulate cellular functions, and generally negative feedback regulates hormone levels.
B) The circulating level of a hormone is held constant through a series of positive feedback loops.
C) Both lipid-soluble hormones and water-soluble hormones bind to intracellular protein receptors.
D) The ducts of endocrine organs release their contents into the bloodstream.
E) Only A and C are true.
A) Hormones regulate cellular functions, and generally negative feedback regulates hormone levels.
What do nitric oxide and epinephrine have in common?
A) They both function as neurotransmitters.
B) They both function as hormones.
C) They are both involved in the ʺfight-or-flightʺ response.
D) They bind the same receptors.
E) Only A and B are correct.
E) Only A and B are correct.
Substance X is secreted by one cell, travels a short distance through interstitial fluid, and produces an effect in a cell immediately adjacent to the original secreting cell. All of the following terms could describe this substance except
A) nitric oxide.
B) neurotransmitter.
C) prostaglandin.
D) pheromone.
E) growth factor.
D) pheromone.
Prostaglandins are local regulators whose basic structure is derived from
A) oligosaccharides.
B) fatty acids.
C) steroids.
D) amino acids.
E) nitric oxide
B) fatty acids.
Which of the following statements about hormones is incorrect?
A) They are secreted into the extracellular fluid.
B) They circulate in blood or hemolymph.
C) They communicate messages throughout the body.
D) They travel through a dedicated pathway.
E) Not all cells respond to a particular hormone.
D) They travel through a dedicated pathway.
Hormone X produces its effect in its target cells via the cAMP second messenger system. Which of the following will produce the greatest effect in the cell?
A) a molecule of hormone X applied to the extracellular fluid surrounding the cell
B) a molecule of hormone X injected into the cytoplasm of the cell
C) a molecule of cAMP applied to the extracellular fluid surrounding the cell
D) a molecule of cAMP injected into the cytoplasm of the cell
E) a molecule of activated, cAMP-dependent protein kinase injected into the cytoplasm of the cell
A) a molecule of hormone X applied to the extracellular fluid surrounding the cell
Which of the following statements about hormones that promote homeostasis is incorrect?
A) A stimulus causes an endocrine cell to secrete a particular hormone.
B) The hormone travels in the bloodstream to target cells.
C) Specific receptors bind with the hormone.
D) Signal transduction brings about a response in the target cell.
E) This response feeds back to promote the release of more hormone.
E) This response feeds back to promote the release of more hormone.
The endocrine system and the nervous system are structurally related. Which of thefollowing cells best illustrates this relationship?
A) a neuron in the spinal cord
B) a steroid-producing cell in the adrenal cortex
C) a neurosecretory cell in the hypothalamus
D) a brain cell in the cerebral cortex
E) a cell in the pancreas that produces digestive enzymes
C) a neurosecretory cell in the hypothalamus
Oxytocin and ADH are produced by the __________ and stored in the __________.
A) hypothalamus; neurohypophysis
B) adenohypophysis; kidneys
C) anterior pituitary; thyroid
D) adrenal cortex; adrenal medulla
E) posterior pituitary; anterior pituitary
A) hypothalamus; neurohypophysis
Which combination of hormones helps a mother to produce milk and nurse her baby?
A) prolactin and calcitonin
B) oxytocin and prolactin
C) follicle-stimulating hormone and luteinizing hormone
D) luteinizing hormone and oxytocin
E) oxytocin, prolactin, and luteinizing hormone
B) oxytocin and prolactin
Prolactin stimulates mammary gland growth and development in mammals and regulates salt and water balance in freshwater fish. Many scientists think that this wide range of functions indicates which of the following?
A) Prolactin is a nonspecific hormone.
B) Prolactin has a unique mechanism for eliciting its effects.
C) Prolactin is an evolutionary conserved hormone.
D) Prolactin is derived from two separate sources.
E) Prolactin interacts with many different receptor molecules.
C) Prolactin is an evolutionary conserved hormone.
The star of a recent movie was a caterpillar that never matured into an adult. It simply got larger with each molt. What is the probable reason why the caterpillar did not mature intoan adult?
A) lack of ecdysone
B) lack of juvenile hormone
C) decreased level of ecdysone
D) increased level of juvenile hormone
E) lack of the melatonin hormone
D) increased level of juvenile hormone
Which of the following is an endocrine gland?
A) parathyroid gland
B) salivary gland
C) sweat gland
D) sebaceous gland
E) gallbladder
A) parathyroid gland
