Nursing Elites

1. Which type of wave does not require a medium for propagation?

• A. Transverse wave
• B. Longitudinal wave
• C. Mechanical wave
• D. Electromagnetic wave

Correct answer: D

Rationale: The correct answer is D, Electromagnetic wave. Electromagnetic waves do not require a medium for propagation because they consist of oscillating electric and magnetic fields that can travel through a vacuum. In contrast, transverse and longitudinal waves are mechanical waves that require a medium (solid, liquid, or gas) for propagation. Therefore, options A, B, and C are incorrect as they are all types of mechanical waves that necessitate a medium for transmission.

2. What is the 'lock-and-key' model?

• A. Protein folding
• B. Enzyme-substrate interaction
• C. Muscle contraction
• D. Blood clotting

Correct answer: B

Rationale: The 'lock-and-key' model describes the specificity of the interaction between enzymes and their substrates. In this model, the enzyme's active site acts like a lock that can only be opened by the specific substrate molecule, which serves as the key. This specific binding ensures that enzymes catalyze particular reactions and do not interact with other molecules indiscriminately. Protein folding (option A) is the process by which a protein attains its functional three-dimensional structure but is not directly related to the lock-and-key model. Muscle contraction (option C) and blood clotting (option D) are complex biological processes but are not directly associated with the lock-and-key model of enzyme-substrate interaction.

3. Which of the following stimulates adaptive immunity?

• A. Peptides
• B. Phagocytes
• C. Prions
• D. Platelets

Correct answer: C

Rationale: The correct answer is C: Prions. Prions are infectious proteins that can stimulate an adaptive immune response by triggering the production of specific antibodies. Peptides are fragments of proteins and can be processed and presented by antigen-presenting cells to activate T cells, which play a role in adaptive immunity. Phagocytes, such as macrophages, are part of the innate immune system and are involved in engulfing and destroying pathogens, but they do not directly stimulate adaptive immunity. Platelets are primarily involved in blood clotting and are not directly related to stimulating adaptive immunity.

4. Which of the following neurotransmitters slows down the activity of neurons, preventing them from becoming overexcited?

• A. Acetylcholine
• B. Dopamine
• C. GABA
• D. Serotonin

Correct answer: C

Rationale: The correct answer is C: GABA (gamma-aminobutyric acid). GABA acts as an inhibitory neurotransmitter that reduces neuronal activity, thus preventing overexcitation. Acetylcholine (choice A) is involved in muscle control and cognitive function, but it is not primarily responsible for slowing down neuronal activity. Dopamine (choice B) plays a role in reward-motivated behavior and motor control, rather than inhibiting neuronal firing. Serotonin (choice D) is involved in mood regulation, sleep, and appetite but does not primarily slow down neuronal activity to prevent overexcitation.

5. What are the three types of muscle tissues?

• A. Cardiac, smooth, epithelial
• B. Skeletal, cardiac, smooth
• C. Cardiac, smooth, connective
• D. Skeletal, epithelial, connective

Correct answer: B

Rationale: The correct answer is B: Skeletal, cardiac, smooth. Skeletal muscle tissue is responsible for voluntary movement, cardiac muscle tissue is found in the heart and is responsible for involuntary heart contractions, and smooth muscle tissue is located in organs and is responsible for involuntary movements. Therefore, the three types of muscle tissues are skeletal, cardiac, and smooth. Choices A, C, and D are incorrect because they include types of tissues that are not classified as muscle tissues. Epithelial and connective tissues are different types of tissues that serve other functions in the body, not related to muscle contractions.

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