Nursing Elites

1. What is the small repeating unit in the contractile apparatus of skeletal muscle?

• A. Myofibril
• B. Actin
• C. Sarcomere
• D. Myosin

Correct answer: C

Rationale: The correct answer is 'Sarcomere.' The sarcomere is the smallest repeating unit within myofibrils and is responsible for muscle contraction in skeletal muscle. It consists of overlapping actin and myosin filaments arranged in a highly organized structure that allows for the sliding of filaments during muscle contraction. 'Myofibril' (choice A) is incorrect because it is a larger structure composed of sarcomeres. 'Actin' (choice B) and 'Myosin' (choice D) are incorrect as they are individual proteins that are components of the sarcomere, not the smallest repeating unit itself.

2. What is the primary function of nephrons?

• A. Store urine
• B. Filter blood and remove waste products
• C. Produce hormones
• D. Control blood pressure

Correct answer: B

Rationale: Nephrons are the functional units of the kidneys responsible for filtering blood to remove waste products, excess ions, and water. This process leads to the formation of urine, aiding in maintaining the body's fluid and electrolyte balance. The primary function of nephrons is not to store urine but to filter blood and eliminate waste products. Choice C, 'Produce hormones,' is incorrect as nephrons primarily focus on filtration rather than hormone production. Choice D, 'Control blood pressure,' is also incorrect as while the kidneys do play a role in regulating blood pressure, it is not the primary function of nephrons within the kidneys.

3. What might happen if blood sugar begins to drop in the human body?

• A. The pancreas releases insulin.
• B. The liver releases stored glucose.
• C. The liver stores glucose as glycogen.
• D. The pancreas releases glucagon.

Correct answer: D

Rationale: When blood sugar levels drop in the body, the pancreas releases glucagon. Glucagon acts to increase blood sugar levels by stimulating the liver to release stored glucose into the bloodstream. Therefore, the correct answer is D. Choice A is incorrect because the release of insulin lowers blood sugar levels, opposite of what happens when blood sugar is dropping. Choice B is incorrect as the liver releases stored glucose in response to low blood sugar, not when blood sugar is already dropping. Choice C is also incorrect as the liver stores glucose as glycogen but doesn't directly impact blood sugar levels dropping in the moment.

4. Which of the following statements is FALSE?

• A. An organelle is a specialized structure in a cell, such as a ribosome.
• B. An organ is made up of different types of tissues that work together to perform specific functions.
• C. Organ systems are two or more organs performing similar functions.
• D. A tissue contains a variety of cells that work together to perform a specific function.

Correct answer: B

Rationale: The statement provided in Option B is FALSE. Organs are actually made up of different types of tissues that work together to perform specific functions, rather than being composed of similar tissues. Organs consist of various tissues, each with their own specialized functions that collectively contribute to the overall function of the organ. Options A, C, and D are true statements. Option A correctly defines an organelle as a specialized structure in a cell, like a ribosome. Option C accurately describes organ systems as multiple organs working together to perform related functions. Option D correctly explains that a tissue is composed of different cells working together to carry out a specific function.

5. Which of the following best defines the term amphoteric?

• A. A substance that conducts electricity due to ionization when dissolved in a solvent
• B. A substance that can act as an acid or a base depending on the properties of the solute
• C. A substance that, according to the Brønsted-Lowry Acid-Base Theory, is a proton-donor
• D. A substance that donates its proton and forms its conjugate base in a neutralization reaction

Correct answer: B

Rationale: An amphoteric substance can act as both an acid or a base depending on the environment. It can donate a proton (act as an acid) or accept a proton (act as a base), showing versatility in its behavior. Choice A is incorrect as it describes an electrolyte rather than an amphoteric substance. Choice C is incorrect as it defines an acid based on the Brønsted-Lowry Acid-Base Theory. Choice D is incorrect as it specifically refers to a substance donating a proton in a neutralization reaction, not capturing the dual behavior of an amphoteric substance.

Similar Questions