Nursing Elites

1. The adaptive immune system has two main branches: humoral and cell-mediated immunity. Which type of immune cell is primarily responsible for antibody production?

• A. Helper T cells
• B. Cytotoxic T cells
• C. B cells
• D. Natural killer cells

Correct answer: C

Rationale: B cells are primarily responsible for antibody production in the adaptive immune system. When activated, B cells differentiate into plasma cells, which are specialized to produce antibodies. Helper T cells play a crucial role in activating B cells, but they do not directly produce antibodies. Cytotoxic T cells are involved in cell-mediated immunity by killing infected cells, while natural killer cells are part of the innate immune system and target virus-infected and cancerous cells. Therefore, the correct answer is C (B cells) as they are directly involved in the production of antibodies, essential for humoral immunity.

2. What happens to the kinetic energy of an object when its mass is doubled?

• A. Kinetic energy remains the same
• B. Kinetic energy halves
• C. Kinetic energy doubles
• D. Kinetic energy quadruples

Correct answer: A

Rationale: The correct answer is that the kinetic energy remains the same. Kinetic energy is directly proportional to the mass of an object and the square of its velocity. When the mass is doubled, the kinetic energy would increase if the velocity remains constant. However, in this question, only the mass is mentioned, not the velocity. Therefore, when the mass is doubled, the kinetic energy remains the same as long as the velocity remains constant. Choices B, C, and D are incorrect because they incorrectly suggest changes in kinetic energy that do not accurately reflect the relationship between mass and kinetic energy described in the question.

3. What is the smallest bone in the human body?

• A. Stapes (Middle ear bone)
• B. Patella (Kneecap)
• C. Phalanges (Finger bones)
• D. Ribs

Correct answer: A

Rationale: The correct answer is A: Stapes (Middle ear bone). The stapes, located in the middle ear, is indeed the smallest bone in the human body. Despite its small size, the stapes is vital for hearing as it transmits and amplifies sound vibrations, contributing significantly to auditory perception. Choices B, C, and D are incorrect. The patella (kneecap) is the largest sesamoid bone in the human body, not the smallest bone. Phalanges are the bones in fingers and toes, not the smallest bone overall. Ribs are long bones that protect the chest cavity, not the smallest bone in the body.

4. What makes bone resistant to shattering?

• A. The calcium salts deposited in the bone
• B. The collagen fibers
• C. The bone marrow and network of blood vessels
• D. The intricate balance of minerals and collagen fibers

Correct answer: D

Rationale: Bone is resistant to shattering due to the intricate balance of minerals and collagen fibers. The minerals provide strength to the bone, while the collagen fibers offer flexibility. This combination ensures that bone is a robust and resilient tissue. Choice A (The calcium salts deposited in the bone) is incorrect as calcium salts alone do not provide the necessary flexibility for bone to withstand shattering. Choice B (The collagen fibers) is partially correct as collagen fibers contribute to the flexibility of bone but alone are not sufficient for resistance to shattering. Choice C (The bone marrow and network of blood vessels) is incorrect as they do not directly contribute to the physical resistance of bone to shattering.

5. Which of the following macromolecules will always contain nitrogen?

• A. Fatty acids
• B. Proteins
• C. Lipids
• D. Carbohydrates

Correct answer: B

Rationale: The correct answer is B: Proteins. Proteins are the only macromolecules that always contain nitrogen in their amino acid structure. Nitrogen is a key element found in the amino groups of amino acids, which are the building blocks of proteins. Fatty acids (Choice A), lipids (Choice C), and carbohydrates (Choice D) do not always contain nitrogen in their structure. Fatty acids are composed of long hydrocarbon chains and do not contain nitrogen. Lipids consist mainly of carbon, hydrogen, and oxygen, with some classes of lipids containing phosphorus but not nitrogen. Carbohydrates are made up of carbon, hydrogen, and oxygen, forming structures like sugars and starches, but they do not contain nitrogen.

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