In areas of permafrost, stands of black spruce are frequently observed in the landscape, while other tree species are noticeably absent. Often these stands are referred to as "drunken forests" because many of the black spruce often "lean over" (that is, they are displaced from their normal vertical alignment). What is the most likely explanation for the unusual growth of these forests in this marginal habitat?

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#Question id: 12950

#Unit 7. System Physiology – Animal

Increases in both renal blood flow and GFR are caused by which of the following?

TLS Online TPP Program

#Question id: 12949

#Unit 7. System Physiology – Animal

At which renal tubular sites would the concentration of creatinine be expected to be highest in a normally hydrated person?

TLS Online TPP Program

#Question id: 12701

#Unit 7. System Physiology – Animal

In chronic respiratory acidosis with partial renal compensation, you would expect to find the following changes, compared to normal:___ urinary excretion of NH4+; ______ plasma HCO3− concentration; and _____ urine pH.

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#Question id: 12700

#Unit 7. System Physiology – Animal

A young man is found comatose, having taking an unknown number of sleeping pills an unknown time before. An arterial blood sample yields the following values: pH = 7.02, HCO3− = 14 mEq/L, and PCO2 = 68 mm Hg. This patient’s acid–base status is most accurately described as

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?