Nursing Elites

1. Which part of the brain is responsible for coordinating muscle movements, maintaining balance, and posture?

• A. Cerebrum
• B. Cerebellum
• C. Medulla oblongata
• D. Thalamus

Correct answer: B

Rationale: The correct answer is B, the cerebellum. The cerebellum plays a crucial role in coordinating muscle movements, maintaining balance, and posture. It receives inputs from sensory systems, the spinal cord, and other brain regions to fine-tune motor movements. The cerebrum, choice A, is primarily involved in higher brain functions like thinking and decision-making. The medulla oblongata, choice C, controls essential functions such as breathing and heart rate. The thalamus, choice D, serves as a relay center for sensory information but is not directly responsible for coordinating muscle movements, balance, or posture.

2. In the reaction 2H2 + O2 → 2H2O, how many moles of oxygen are required to react completely with 4 moles of hydrogen?

• A. 1
• B. 2
• C. 3
• D. 4

Correct answer: B

Rationale: The balanced chemical equation indicates that 2 moles of H2 react with 1 mole of O2 to produce 2 moles of H2O. To determine how many moles of O2 are required to react with 4 moles of H2, you can use the mole ratio from the balanced equation: 2 moles of H2 react with 1 mole of O2. Therefore, to react completely with 4 moles of H2, you would need 2 moles of O2 (4 moles H2 ÷ 2 moles H2 per 1 mole O2). Hence, 2 moles of oxygen are required to react completely with 4 moles of hydrogen. Choices A, C, and D are incorrect because they do not reflect the correct stoichiometry as defined by the balanced chemical equation.

3. Identify the function NOT attributed to the lymphatic system.

• A. Fluid drainage from tissues
• B. Immune response via white blood cell production
• C. Nutrient transport throughout the body
• D. Waste removal through lymph nodes

Correct answer: C

Rationale: A) Fluid drainage from tissues: This function is attributed to the lymphatic system. Lymphatic vessels collect excess fluid from tissues and return it to the bloodstream. B) Immune response via white blood cell production: The lymphatic system plays a crucial role in the body's immune response by producing and transporting white blood cells, such as lymphocytes, which help fight infections. C) Nutrient transport throughout the body: Nutrient transport is primarily carried out by the circulatory system (blood vessels), not the lymphatic system. The circulatory system transports nutrients, oxygen, and hormones to cells and removes waste products. D) Waste removal through lymph nodes: The lymphatic system helps remove waste and toxins from the body by filtering lymph through lymph nodes, where harmful substances are trapped and destroyed by immune cells. Therefore, the function NOT attributed to the lymphatic system is C) Nutrient transport throughout the body.

4. Which structure allows for the selective passage of materials into and out of the cell?

• A. DNA
• B. Protein
• C. Carbohydrate
• D. Phospholipid bilayer

Correct answer: D

Rationale: The phospholipid bilayer is a crucial component of the cell membrane, surrounding the cell and regulating the passage of materials into and out of the cell. Its structure enables it to be selectively permeable, controlling which substances can pass through. DNA, proteins, and carbohydrates are essential molecules in the cell but do not directly govern the passage of materials like the phospholipid bilayer does. Therefore, the correct answer is the phospholipid bilayer.

5. How does polarization affect the intensity of light passing through a polarizing filter?

• A. All light passes through regardless of polarization.
• B. Light with the same polarization as the filter passes through, while others are blocked.
• C. Light with higher intensity passes through, while weaker light is blocked.
• D. The intensity is reduced for all light, regardless of polarization.

Correct answer: B

Rationale: A polarizing filter only allows light waves with a specific orientation (polarization) to pass through while blocking light waves with different orientations. Therefore, light with the same polarization as the filter will pass through, while light with different polarizations will be blocked. This results in a reduction in intensity for light passing through the polarizing filter. Choice A is incorrect because a polarizing filter selectively filters light based on its polarization. Choice C is incorrect as the intensity of light passing through is determined by its polarization, not solely its intensity. Choice D is incorrect because a polarizing filter affects light based on its polarization, not uniformly reducing the intensity for all light passing through.

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