BIO 394 Exam 2 Key

A patient with previously diagnosed epidermolysis bullosa comes in for a check-up. They ask you what mutation causes their condition. Which of the following would NOT be a likely cause?

Calcitonin

TGF-β signaling can increase the expression of elastase. Given this information, what would be a logical result of a germ-line mutation in the TβRIII co-receptor that prevents it from being shed from the cell surface?

Marfans Syndrome-like symptoms

Why do people with Ehlers-Danlos Syndrome have hyper-elastic skin?

Mutated collagen reduces tensile strength of skin

Batrachotoxin from poison dart frogs can have lethal effects from locking sodium channels into an open confirmation. Which of the following is an accurate explanation of how this toxin works?

The toxin prevents repolarization of neurons.

Viper venoms are frequently hemotoxic. With this knowledge, which of the following toxins is least likely to be present in viper venom?

a-Amanitin (RNA Pol II inhibitor)

Which of the following would you expect in a theoretical case of a patient with adrenal gland dysfunction?

Hypotension

SGK1 inactivates NEDD4, the ubiquitin-ligase that targets the sodium channel ENaC. Given this, which of the following is most likely true?

SGK1 is activated by aldosterone

Cushing’s syndrome is characterized by overproduction of cortisol. Which of the following would you predict to be a common symptom of Cushing’s?

Slow wound healing

Androgen is a steroid hormone, derived from cholesterol. How might androgen exert its effects on a cell?

DNA-binding intracellular receptor

Lipocortin-1 suppresses the expression of integrins necessary for leukocytes to exit the bloodstream and enter tissues. Which hormone will most likely increase lipocortin-1 expression?

Cortisol

Phospholipase A2 in viper venom cleaves phospholipids, disrupting endothelial cell membranes. In a bite victim, this contributes to:

Bleeding from compromised blood vessels

In PCOS, hyperandrogenism can change the pulse rate of GnRH, altering the balance of LH and FSH. Which of the following statements is NOT true regarding this dysregulation?

Ovulation is preventing by blocking FSH surge

Untreated type 1 diabetes leads to DKA because of which of the following?

Cells use fats for energy, producing acidic ketones

RANKL binds receptors on immature osteoclasts to promote their differentiation. Which hormone would likely stimulate the release of RANKL?

Parathyroid Hormone

What would most likely happen if a patient was treated with supplemental T3 thyroid hormone?

Weight loss

Diabetes insipidus is caused by dysregulation of anti-diuretic hormone, and is characterized by high output of dilute urine. How does ADH play a role in producing these symptoms?

Loss of ADH leads to decreased aquaporin expression in the nephron.

In PCOS, hyperandrogenism prevents the normal progesterone surge from the corpus luteum. The lack of a progesterone surge leads to:

Unstable endometrium and amenorrhea

What are three uses or functions of proteoglycans?

Space filler

shock absorber

anchor point for cells

form hydration gel

sequester signaling molecules