Nursing Elites

1. Which protein complex in the sarcomere is responsible for the thick filament?

• A. Actin
• B. Myosin
• C. Tropomyosin
• D. Troponin

Correct answer: B

Rationale: The correct answer is B: Myosin. In the sarcomere, the thick filament is composed of myosin protein. Myosin is responsible for the interaction with actin filaments during muscle contraction, forming cross-bridges that generate the force required for muscle movement. Actin (choice A) is a component of the thin filament in the sarcomere, while tropomyosin (choice C) and troponin (choice D) are regulatory proteins associated with muscle contraction but are not part of the thick filament. Understanding the specific components of the sarcomere is crucial for comprehending muscle contraction mechanisms.

2. A playground fence has a rectangular section (5m by 3m) attached to a semicircular section with a radius of 2m. What is the total perimeter?

• A. 13m
• B. 16m
• C. 19m
• D. 22m

Correct answer: D

Rationale: Calculate the semicircle perimeter (π * radius) and add it to the rectangular perimeter: perimeter = π * radius + 2 (length + width) ≈ 3.14 * 2m + 2 (5m + 3m) ≈ 6.28m + 16m ≈ 22.28m ≈ 22m (rounded).

3. Which of the following is an example of static friction?

• A. Sliding a heavy box across the floor
• B. A car moving around a curve
• C. Pushing a stationary object
• D. Braking a car to stop

Correct answer: c

Rationale: Static friction occurs when an object is at rest and prevents it from moving when a force is applied.

4. Which of the following is a common characteristic of alkynes?

• A. They have a triple bond between carbon atoms.
• B. They are saturated hydrocarbons.
• C. They contain only single bonds.
• D. They are aromatic compounds.

Correct answer: A

Rationale: Alkynes are hydrocarbons that contain at least one triple bond between carbon atoms. This triple bond is a distinctive feature of alkynes, distinguishing them from alkanes (which contain only single bonds) and alkenes (which contain at least one double bond). Alkynes are unsaturated hydrocarbons due to the presence of the triple bond. Aromatic compounds, on the other hand, have a specific cyclic structure with resonance stabilization, which is not a characteristic of alkynes.

5. How does the amplitude of a wave relate to its intensity or loudness?

• A. They are inversely proportional.
• B. They are directly proportional.
• C. They have no relationship.
• D. Amplitude affects frequency, not intensity.

Correct answer: B

Rationale: Higher amplitude corresponds to larger displacement from equilibrium and translates to higher intensity or perceived loudness in sound waves.

6. When light interacts with a perfectly smooth surface, like a mirror, the dominant interaction is:

• A. Refraction
• B. Diffraction
• C. Total internal reflection
• D. Specular reflection

Correct answer: D

Rationale: The correct answer is D: Specular reflection. When light interacts with a perfectly smooth surface like a mirror, it undergoes specular reflection, where the light rays are reflected at the same angle as the incident angle. Refraction (option A) occurs when light passes from one medium to another at an angle, causing it to change direction. Diffraction (option B) is the bending of light waves around obstacles or through small openings. Total internal reflection (option C) occurs when light traveling in a medium strikes the boundary with another medium at an angle greater than the critical angle, causing the light to reflect back into the original medium. In the case of a perfectly smooth surface, specular reflection is the dominant interaction as the light rays reflect in a single direction with minimal scattering or diffraction.

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