You conduct an experiment on twenty 18-year-old male subjects to see how various levels of exercise influence heart rate. Explain why only 18 -year-old males were used as subjects.
What will be an ideal response?
An important part of scientific inquiry is to remove sources of variation from among subjects. By choosing subjects of one gender in a particular age group, it is easier to determine that the dependent variable (heart rate, in this case) depends only on the independent variable, level of exercise. This also allows a study to have fewer participants, assuming that subjects were randomly assigned to a level of exercise. If subjects were of random ages and genders, data would have to be collected from many more individuals.
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A gluteal gait, in which a person walks with a waddling limp, is usually caused by a disorder of the
A. gluteus maximus and tensor fasciae latae. B. gluteus maximus and gluteus minimus. C. gluteus medius and gluteus minimus. D. gluteus maximus and gluteus medius.
Which of the following statements concerning the nephron loop and its function is FALSE?
Sodium and chloride are pumped out of the thin descending limb of the nephron loop. The nephron loop reabsorbs roughly half the water and two-thirds of the sodium and chloride ions in the tubular fluid. Water moves by osmosis out of the descending limb of the nephron loop. The pumping of sodium and chloride from the nephron loop elevates the osmotic concentration in the peritubular fluid.
Which one of the following is NOT a feature of chronic obstructive pulmonary disease (COPD)?
A) Most patients have a genetic predisposition to COPD. B) Dyspnea becomes progressively more severe. C) Frequent pulmonary infections are common. D) Most COPD victims are hypoxic. E) Most patients have a history of smoking.
Which cranial nerve is responsible for moving the eye laterally:
A) cranial nerve VIII (vestibulocochlear) B) cranial nerve III (oculomotor) C) cranial nerve II (optic) D) cranial nerve IV (trochlear) E) cranial nerve VI (abducens)