Nursing Elites

1. When light reflects from a surface, what determines the angle of reflection?

• A. The material of the surface
• B. The wavelength of the light
• C. The angle of incidence
• D. The intensity of the light

Correct answer: C

Rationale: The angle of reflection is determined by the angle of incidence according to the law of reflection, which states that the angle of incidence is equal to the angle of reflection. When light reflects off a surface, the angle at which it strikes the surface (angle of incidence) is the key factor in determining the angle at which it reflects (angle of reflection). The material of the surface, the wavelength of the light, and the intensity of the light do not directly influence the angle of reflection in this context. Therefore, the correct answer is the angle of incidence (Choice C). The material of the surface (Choice A) does affect other properties like reflectivity but does not directly determine the angle of reflection. The wavelength of the light (Choice B) determines its color or frequency but not the angle of reflection. The intensity of the light (Choice D) is related to the brightness of the light but does not dictate the angle at which light reflects from a surface.

2. Which vitamin requires intrinsic factor for proper absorption?

• A. Vitamin A
• B. Vitamin C
• C. Vitamin D
• D. Vitamin B12

Correct answer: D

Rationale: Vitamin B12 requires intrinsic factor, a glycoprotein secreted by the parietal cells of the stomach, for proper absorption in the small intestine. Intrinsic factor binds to vitamin B12 and facilitates its absorption in the ileum. Deficiency in intrinsic factor can lead to pernicious anemia, a condition characterized by a lack of vitamin B12 absorption. Options A, B, and C are incorrect. Vitamin A is absorbed in the small intestine with the help of bile salts; Vitamin C is absorbed in the small intestine via active transport; Vitamin D is absorbed in the small intestine through a process involving bile salts and micelles. It is essential for students to understand this relationship as it highlights the importance of intrinsic factor in the absorption of specific vitamins and the consequences of its deficiency.

3. What is a condition characterized by an overactive thyroid gland and excessive production of thyroid hormones called?

• A. Diabetes mellitus
• B. Hyperthyroidism
• C. Hypothyroidism
• D. Cushing's syndrome

Correct answer: B

Rationale: Hyperthyroidism is a condition where the thyroid gland is overactive and produces an excessive amount of thyroid hormones. This can lead to symptoms such as weight loss, rapid heartbeat, sweating, and nervousness. Diabetes mellitus is a condition characterized by high blood sugar levels due to either insufficient insulin production or the body's inability to respond to insulin. Hypothyroidism is the opposite of hyperthyroidism, where the thyroid gland is underactive and produces insufficient thyroid hormones. Cushing's syndrome is a disorder that occurs when the body has a high level of the hormone cortisol for a long time.

4. What is the term for a repetitive, involuntary muscle contraction that can cause pain and stiffness?

• A. Cramp
• B. Spasm
• C. Tic
• D. Fibrosis

Correct answer: B

Rationale: A spasm is a repetitive, involuntary muscle contraction that can cause pain and stiffness. While cramps are a type of spasm, not all spasms are cramps. Tics are sudden, repetitive movements or sounds made involuntarily. Fibrosis refers to the formation of excess fibrous connective tissue in an organ or tissue as part of a reparative or reactive process. In this context, a spasm best fits the description provided, making it the correct answer. Cramp, although related to spasms, is more specific and not the general term being sought. Tic does not describe a muscle contraction but rather sudden movements or sounds. Fibrosis does not directly relate to muscle contractions but rather to the formation of excess fibrous tissue in organs or tissues.

5. What is the difference between DNA and RNA?

• A. Both are double-stranded.
• B. DNA contains deoxyribose sugar, while RNA contains ribose sugar.
• C. RNA contains the nitrogenous base uracil, while DNA contains thymine.
• D. Both are identical molecules.

Correct answer: B

Rationale: A) Incorrect. DNA is double-stranded, but RNA is typically single-stranded. B) Correct. DNA contains deoxyribose sugar, which lacks an oxygen atom on the 2' carbon of the sugar ring, while RNA contains ribose sugar, which has an additional hydroxyl group on the 2' carbon. C) Incorrect. RNA contains the nitrogenous base uracil, while DNA contains thymine. D) Incorrect. DNA and RNA have distinct structures and functions, so they are not identical molecules.

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