What is the medical term for an abnormal decrease in red blood cells?

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: D

Rationale: The correct answer is D - All of the above. Lectin receptors recognize microbial carbohydrates, are expressed on phagocytes, and can be classified as pattern recognition receptors. Lectins are proteins that bind specifically to certain carbohydrates, allowing them to recognize and interact with pathogens. Phagocytes express lectin receptors to help identify and engulf pathogens. Additionally, lectin receptors are considered pattern recognition receptors because they recognize specific patterns or structures commonly found on pathogens. Therefore, all three statements are true, making option D the correct answer.

Correct Answer: B

Rationale: The correct answer is B: Increased concentration of C-reactive protein. This is because C-reactive protein is a well-established clinical indicator of inflammation, produced by the liver in response to inflammation. Choice A is incorrect because a decreased concentration of C3b is not a typical indicator of inflammation. Choice C is incorrect because mannose-binding lectin (MBL) is an acute-phase reactant that increases in response to inflammation, so a decreased concentration of MBL would not be indicative of inflammation. Choice D is incorrect as it includes all options, but only B is a valid clinical indicator of inflammation.

Correct Answer: A

Rationale: The correct answer is A because the term 'lymphocyte repertoire' specifically refers to the range of antigen receptor specificities found in a lymphocyte population. Lymphocytes are immune cells that play a crucial role in recognizing and responding to antigens, and their diverse antigen receptor specificities allow them to recognize a wide range of pathogens. This term does not refer to effector functions (B) or a single lymphocyte's receptor specificities (C). Additionally, it does not describe the collection of daughter cells produced after division (D), as the repertoire refers to the initial diversity of antigen receptors within a lymphocyte population.

Correct Answer: A

Rationale: The correct answer is A. Virus typically triggers a Th1 response because Th1 cells are specialized in combating intracellular pathogens like viruses. Th2 response is more common for extracellular parasites, making choice B incorrect. TH17 response is usually associated with fungal infections and autoimmune diseases, making choice C incorrect. Parasitic worms usually induce a Th2 response due to their extracellular nature, making choice D incorrect.