Practice Questions

  1. Home
  2. Free Resources
  3. Practice Questions
  4. 55346
TLS Online TPP Program

#Question id: 1262

Although MAP kinase is often activated in multicellular animals by RTKs or cytokine receptors, signaling from other receptors can activate MAP kinase in other eukaryotic cells. we consider the mating pathway in the yeast S. cerevisiae, a well-studied example of a MAP kinase cascade linked to G protein–coupled receptors (GPCRs). Which of the following statement is incorrect?

#Unit 4. Cell Communication and Cell Signaling

  1. An a haploid cell secretes the a mating factor and has GPCRs for the α factor on its cell surface; an α cell secretes the α factor and has GPCRs for the a factor. Thus each type of cell recognizes the mating factor produced by the opposite type.

  2. Ligand binding and dissociation of the G protein subunits, the membrane-tethered Gβγ subunit binds the Ste5 scaffold to the plasma membrane.

  3. Gβγ also activates Cdc24, a GAP for the Ras-like protein Cdc42; the active, GTP-bound Cdc42, in turn, binds to and activates the Ste20 kinase.

  4. Ste20 then phosphorylates and activates Ste11, which is analogous to Raf and other mammalian MEK kinase (MEKK) proteins. Ste20 thus serves as a MAPKKK kinase.

More Questions
TLS Online TPP Program

#Question id: 12699

#Unit 7. System Physiology – Animal

The following test results were obtained: urine flow rate = 2.0 ml/min; urine inulin concentration = 60 mg/ml; plasma inulin concentration = 2 mg/ml; urine potassium concentration = 20 μmol/ml; plasma potassium concentration = 4.0 μmol/ml; urine osmolarity = 150 mOsm/L; and plasma osmolarity = 300 mOsm/L. What is the free water clearance rate?
TLS Online TPP Program

#Question id: 12698

#Unit 7. System Physiology – Animal

The following test results were obtained: urine flow rate = 2.0 ml/min; urine inulin concentration = 60 mg/ml; plasma inulin concentration = 2 mg/ml; urine potassium concentration = 20 μmol/ml; plasma potassium concentration = 4.0 μmol/ml; urine osmolarity = 150 mOsm/L; and plasma osmolarity = 300 mOsm/L. What is the net potassium reabsorption rate?
TLS Online TPP Program

#Question id: 12697

#Unit 7. System Physiology – Animal

The following test results were obtained: urine flow rate = 2.0 ml/min; urine inulin concentration = 60 mg/ml; plasma inulin concentration = 2 mg/ml; urine potassium concentration = 20 μmol/ml; plasma potassium concentration = 4.0 μmol/ml; urine osmolarity = 150 mOsm/L; and plasma osmolarity = 300 mOsm/L. What is the approximate GFR?
TLS Online TPP Program

#Question id: 12659

#Unit 7. System Physiology – Animal

 Which of the following would tend to decrease plasma potassium concentration by causing a shift of potassium from the extracellular fluid into the cells?
TLS Online TPP Program

#Question id: 12658

#Unit 7. System Physiology – Animal

In a person on a high (200 mmol/day) potassium diet, which part of the nephron would be expected to secrete the most potassium?
TLS Online TPP Program

#Question id: 12561

#Unit 7. System Physiology – Animal

Given the following measurements, calculate the filtration fraction: glomerular capillary hydrostatic pressure = 50 mm Hg; Bowman’s space hydrostatic pressure = 15 mm Hg; colloid osmotic
pressure in the glomerular capillaries = 30 mm Hg; glomerular capillary filtration coefficient (Kf) = 12 ml/min/mm Hg; and renal plasma flow = 400 ml/min.