CPSS Foundational Scientific Disciplines 2 — Questions and Answers
Question 1: Which muscle fiber type relies predominantly on oxidative phosphorylation for ATP production during prolonged endurance exercise?
- Type IIx fibers
- Type IIa fibers
- Type I fibers (Correct answer)
- Type IIb fibers
Correct answer: Type I fibers
Type I (slow-twitch) fibers have high mitochondrial density and rely primarily on oxidative phosphorylation, making them fatigue-resistant during endurance exercise.
Question 2: In biomechanics, the moment of inertia describes an object's resistance to:
- Linear acceleration
- Rotational acceleration (Correct answer)
- Gravitational pull
- Frictional force
Correct answer: Rotational acceleration
Moment of inertia quantifies how difficult it is to change an object's rotational motion, analogous to mass in linear mechanics.
Question 3: Which neurotransmitter is primarily responsible for excitation at the neuromuscular junction?
- Dopamine
- Serotonin
- Acetylcholine (Correct answer)
- GABA
Correct answer: Acetylcholine
Acetylcholine is released by motor neurons at the neuromuscular junction, binding nicotinic receptors to trigger muscle fiber depolarization.
Question 4: The Fick equation for maximal oxygen uptake (VO2max) is best expressed as:
- VO2max = HR × SV × (CaO2 − CvO2) (Correct answer)
- VO2max = HR × SV × (CvO2 − CaO2)
- VO2max = CO × PaO2
- VO2max = VE × FiO2
Correct answer: VO2max = HR × SV × (CaO2 − CvO2)
The Fick equation states VO2 = cardiac output × arteriovenous oxygen difference (CaO2 − CvO2), where HR × SV equals cardiac output.
Question 5: Which statistical measure is most appropriate for describing the central tendency of a highly skewed distribution of recovery times?
- Mean
- Variance
- Median (Correct answer)
- Standard deviation
Correct answer: Median
The median is resistant to extreme values and better represents central tendency when data are skewed, unlike the mean which is pulled toward outliers.
Question 6: During high-intensity exercise, the primary buffer system combating lactic acid accumulation in the blood is:
- Phosphate buffer system
- Protein buffer system
- Hemoglobin buffer system
- Bicarbonate buffer system (Correct answer)
Correct answer: Bicarbonate buffer system
The bicarbonate buffer system (H⁺ + HCO₃⁻ → H₂CO₃ → H₂O + CO₂) is the most important extracellular buffer for metabolic acids during intense exercise.
Question 7: In research methodology, internal validity is most threatened by which of the following?
- Small sample size limiting generalizability
- Volunteer bias in participant selection
- Pre-test sensitization confounding results (Correct answer)
- Poorly defined dependent variables
Correct answer: Pre-test sensitization confounding results
Pre-test sensitization (testing effects) is a classic threat to internal validity because exposure to initial measurement can alter participants' responses to the intervention.
CPSS Foundational Scientific Disciplines 2
Which muscle fiber type relies predominantly on oxidative phosphorylation for ATP production during prolonged endurance exercise?