Nokea
Which pairing of immune response type and immune response feature is not correct?
- A. Innate: Acts rapidly
- B. Adaptive: Results in memory
- C. Innate: Mediated by lymphocytes
- D. Adaptive: Can distinguish between specific pathogens
Correct Answer: C
Rationale: The correct answer is C because innate immune response is not mediated by lymphocytes. Innate response involves physical barriers, such as skin and mucous membranes, and cells like macrophages and neutrophils. Lymphocytes are part of the adaptive immune response, which is characterized by specificity and memory. Choice A is correct as the innate response acts rapidly due to pre-existing mechanisms. Choice B is correct as adaptive response results in memory cells for quicker response upon re-exposure. Choice D is correct as adaptive response can recognize and respond to specific pathogens through antigen recognition.
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Which of the following white blood cells is small,present in blood and migrates to tissue as necessary?
- A. Neutrophils
- B. Leukocytes
- C. Monocytes
- D. Lymphocytes
Correct Answer: D
Rationale: Lymphocytes are small white blood cells that circulate in the blood and migrate to tissues as needed to participate in immune responses.
What are the three main principles of adaptive immunity?
- A. Respond, Replace, Repair
- B. Recognize, Respond, Remember
- C. Resist, Retain, Recruit
- D. React, Replicate, Restore
Correct Answer: B
Rationale: The three main principles of adaptive immunity are Recognize, Respond, Remember.
1. Recognize: Immune system identifies specific pathogens through antigen recognition.
2. Respond: Immune response is triggered to eliminate the pathogen.
3. Remember: Immune system forms memory cells for faster and stronger response upon re-exposure.
Other options are incorrect:
A: Respond, Replace, Repair - Incorrect as it does not reflect the key processes of adaptive immunity.
C: Resist, Retain, Recruit - Incorrect as these terms do not accurately describe the adaptive immune response.
D: React, Replicate, Restore - Incorrect as it does not encompass the essential principles of adaptive immunity.
What is the primary advantage of Toll-like receptors (TLRs)?
- A. They are highly specific to individual pathogens
- B. They recognize common molecular patterns shared by groups of microbes
- C. They activate B cell antibody production
- D. They require antigen presentation to function
Correct Answer: B
Rationale: The correct answer is B because Toll-like receptors (TLRs) recognize common molecular patterns shared by groups of microbes, allowing for rapid detection of a wide range of pathogens. This recognition triggers immune responses without the need for prior exposure to the specific pathogen. The other choices are incorrect because:
A: TLRs are not highly specific to individual pathogens but rather recognize common patterns.
C: TLRs do not directly activate B cell antibody production; they initiate immune responses by activating various immune cells.
D: TLRs do not require antigen presentation to function; they directly recognize microbial patterns.
NAD and FAD are hydrogen carriers, but cytochromes are electron carriers in bacteria. What happens to the protons (Hâº) in electron transport chains?
- A. They go into solution inside the cytoplasm.
- B. They are taken back by NAD and FAD.
- C. They are carried from cytochromes to oxygen to form water.
- D. They go into solution outside the cytoplasmic membrane.
Correct Answer: D
Rationale: The correct answer is D because in the electron transport chain, protons (H⁺) are pumped across the membrane to create a proton gradient. This gradient is utilized by ATP synthase to produce ATP. Therefore, protons go into solution outside the cytoplasmic membrane. Choices A and B are incorrect because protons do not simply stay in the cytoplasm or get taken back by NAD and FAD. Choice C is incorrect as protons do not directly form water when carried by cytochromes.
Which part of an antibody determines its antigen specificity?
- A. Fc fragment
- B. Fab region
- C. Heavy chain constant region
- D. Light chain constant region
Correct Answer: B
Rationale: The correct answer is B: Fab region. The Fab region of an antibody contains the antigen-binding site, where specific interactions with antigens occur. This region is formed by the variable regions of both the heavy and light chains. The Fc fragment (choice A) is responsible for effector functions, not antigen specificity. The heavy chain constant region (choice C) and light chain constant region (choice D) are not involved in antigen binding, but rather provide structural support and determine the antibody class. Therefore, the Fab region is crucial for antigen specificity due to its variable regions that directly interact with antigens.