Nursing Elites

1. A solution is formed when:

• A. One substance dissolves in another
• B. Two or more substances react chemically
• C. A solid changes to a liquid
• D. None of the above

Correct answer: A

Rationale: One substance dissolves in another. A solution is a homogeneous mixture where one substance (solute) dissolves in another (solvent).

2. What term describes the phenomenon of two waves canceling each other out when they meet?

• A. Refraction
• B. Diffraction
• C. Destructive interference
• D. Constructive interference

Correct answer: C

Rationale: Destructive interference occurs when two waves meet and their amplitudes are such that they cancel each other out, resulting in a wave with a smaller amplitude or no wave at all. This is in contrast to constructive interference, where two waves combine to produce a wave with a larger amplitude. Refraction and diffraction are phenomena related to the bending of waves as they pass through different mediums or obstacles, respectively.

3. Which of the following is NOT a function of the endocrine system?

• A. Regulating growth and development
• B. Maintaining blood sugar levels
• C. Controlling mood and emotions
• D. Facilitating digestion through muscle contractions

Correct answer: D

Rationale: The endocrine system is responsible for producing hormones that regulate various bodily functions. Option D, facilitating digestion through muscle contractions, is actually a function of the muscular and digestive systems, not the endocrine system. The endocrine system primarily regulates growth and development, maintains blood sugar levels through hormones like insulin and glucagon, and also plays a role in controlling mood and emotions through hormones such as serotonin and cortisol. Therefore, option D is correct as it is not a function directly associated with the endocrine system.

4. What is the name of the muscular ring that controls the passage of food from the esophagus to the stomach?

• A. Pyloric sphincter
• B. Cardiac sphincter
• C. Ileocecal valve
• D. Sphincter of Oddi

Correct answer: B

Rationale: The correct answer is B: Cardiac sphincter. The cardiac sphincter, also known as the lower esophageal sphincter, is the muscular ring located at the junction between the esophagus and the stomach. It controls the passage of food from the esophagus into the stomach by opening and closing to prevent reflux of stomach contents back into the esophagus. The other options are incorrect: A) The pyloric sphincter is located at the junction between the stomach and the small intestine, controlling the passage of food from the stomach into the small intestine. C) The ileocecal valve is located between the small intestine and the large intestine. D) The Sphincter of Oddi is located in the duodenum and regulates the flow of bile and pancreatic juice into the small intestine. Therefore, the correct answer is B because it specifically relates to the passage of food from the esophagus to the stomach.

5. Fingernails and toenails are made primarily of:

• A. Collagen (Collagen is found in the dermis)
• B. Keratin
• C. Melanin (Melanin provides pigment, not structure)
• D. Sebum (Sebum is an oily substance)

Correct answer: B

Rationale: The correct answer is B: Keratin. Fingernails and toenails are primarily made of a tough protein called keratin. Keratin is a fibrous structural protein that also makes up hair and the outer layer of skin. Collagen, as mentioned in option A, is found in the dermis of the skin and is responsible for providing strength and elasticity to the skin. Melanin, as in option C, is a pigment that gives color to the skin, hair, and eyes, but it does not contribute to the structure of nails. Sebum, as in option D, is an oily substance produced by the sebaceous glands in the skin to moisturize and protect the skin, but it is not a component of nails.

6. How does the acceleration of an object change if the force acting on it is doubled?

• A. Acceleration is halved
• B. Acceleration doubles
• C. Acceleration remains unchanged
• D. Acceleration quadruples

Correct answer: b

Rationale: According to Newton's second law (F = ma), if force is doubled and mass remains constant, acceleration doubles.

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