Which statement does not describe an example of a feedback mechanism that maintains homeostasis?

Correct Answer: B

Rationale: The correct answer is B because increasing the production of antigens by white blood cells during an allergic reaction is not a feedback mechanism maintaining homeostasis. Homeostasis involves maintaining internal stability despite external changes. A is correct because closing openings in leaves prevents water loss, maintaining plant hydration. C is correct because increased physical activity increases heart rate to maintain oxygen delivery. D is correct because the pancreas releases insulin to regulate blood sugar levels.

Correct Answer: B

Rationale: Correct Answer: B Rationale: 1. Having the client wear a surgical mask helps contain respiratory droplets, reducing the risk of spreading TB. 2. Surgical masks protect others from inhaling infectious particles. 3. Airborne precautions are in place to prevent transmission through the air. 4. Wearing gloves or keeping the client in a negative pressure room does not address airborne transmission. Summary: Choice A is incorrect because the AP should not wear a gown during transport. Choice C is unnecessary as gloves do not prevent airborne transmission. Choice D is incorrect as it does not directly address containing respiratory droplets.

Correct Answer: B

Rationale: The correct answer is B because Raynaud's disease is characterized by reduced blood flow to extremities in response to cold or stress, leading to color changes, numbness, and tissue damage. Wearing layers of clothing helps maintain body heat and prevent cold-induced attacks, protecting against tissue damage. Walking and exercise are beneficial, but not in large intervals as it can trigger attacks. Increasing exposure to cold can worsen symptoms. Limiting fluid intake does not directly impact Raynaud's symptoms.

Correct Answer: C

Rationale: The correct answer is C: calcineurin inhibitor. Tacrolimus falls under this category as it inhibits the enzyme calcineurin, which plays a crucial role in T-cell activation. This action suppresses the immune response and prevents organ rejection. Corticosteroids (choice A) work by suppressing inflammation, antimetabolites (choice B) interfere with nucleic acid metabolism, and monoclonal antibodies (choice D) target specific immune cells or proteins, but they do not directly inhibit calcineurin like tacrolimus.

Correct Answer: C

Rationale: Platelets are manufactured in the bone marrow because it is the primary site of hematopoiesis, where all blood cells, including platelets, are produced. The bone marrow contains stem cells that differentiate into various blood cell types, including platelets. The large intestine and small intestine are not involved in blood cell production. The liver plays a role in blood clotting by producing certain proteins, but it does not manufacture platelets. Therefore, the correct answer is C: The bone marrow.