The release of IL-8 at an infection site specifically induces

Correct Answer: B

Rationale: The correct answer is B because IL-8 is a chemokine that specifically functions to recruit neutrophils to the site of infection. Neutrophils are crucial for fighting off pathogens. A: Increase of adhesion molecules on local endothelial cells is not directly induced by IL-8. C: Systemic effects, including fever, are typically mediated by other cytokines like IL-1 and IL-6. D: Increase of acute-phase proteins is not the primary role of IL-8 in the immune response.

Correct Answer: A

Rationale: The correct answer is A: plants response to stimulation. Tropism refers to the growth or movement of an organism in response to a stimulus. Plants exhibit tropisms such as phototropism (response to light) and geotropism (response to gravity). This choice accurately defines the phenomenon. Choice B is incorrect because reducing lateral branching is not a defining characteristic of tropism. Choice C is incorrect because the length of day and night does not directly relate to tropism. Choice D is incorrect because not all options listed are characteristics of tropism.

Correct Answer: D

Rationale: The correct answer is D because neurons are specialized cells that carry signals, making them the functional units of the nervous system. Neurons consist of a cell body, dendrites, and axons, fulfilling the criteria mentioned in options A, B, and C. Therefore, option D encompasses all the essential characteristics of neurons, making it the correct choice. Options A, B, and C individually do not fully capture the comprehensive nature of neurons, as they only cover specific aspects of what neurons are, whereas option D encompasses all the correct statements regarding neurons.

Correct Answer: C

Rationale: The correct answer is C: Anemia. Anemia is the medical term for an abnormal decrease in red blood cells. Red blood cells are responsible for carrying oxygen throughout the body, and a decrease in their numbers can lead to symptoms like fatigue, weakness, and paleness. Rationale: 1. Leukopenia (A) refers to a decrease in white blood cells, not red blood cells. 2. Thrombocytopenia (B) is a decrease in platelets, which are involved in blood clotting, not red blood cells. 3. Hemolysis (D) is the breakdown of red blood cells, not a decrease in their numbers. In summary, anemia is the correct answer as it specifically describes the condition of low red blood cell count, while the other choices are related to decreases in different components of blood.

Correct Answer: A

Rationale: The correct answer is A: He was the first to observe microorganisms. Van Leeuwenhoek's important contribution to microbiology was his discovery of microorganisms using his own handcrafted microscopes. This observation revolutionized the field by providing the first direct evidence of the existence of microorganisms. Choice B is incorrect because Leeuwenhoek's observations actually supported the idea of spontaneous generation. Choice C is incorrect because he did not link microorganisms to diseases. Choice D is incorrect because the process of fermentation was described by others before Leeuwenhoek.