Nokea
Which of the following correctly explains an epitope?
- A. Region of antibody that binds with antigen
- B. Region of antigen that elicit secretion of specific antibody
- C. Heavy chain of an antibody
- D. V-region of the light chain of antibody
Correct Answer: B
Rationale: Explanation:
An epitope is a specific region on an antigen that elicits the immune response and triggers the production of a specific antibody. Therefore, choice B is correct as it accurately defines an epitope. Choices A, C, and D are incorrect because they do not accurately describe what an epitope is. Choice A refers to the paratope, the region of the antibody that binds to the epitope. Choice C refers to a component of the antibody structure, and choice D refers to a specific region of the antibody structure.
You may also like to solve these questions
Which of the following statements is false about dendritic cells
- A. Found in tissues
- B. Are sessile cells only found in lymph nodes
- C. Express high levels of MHC molecules
- D. Best at activating naïve T cells
Correct Answer: B
Rationale: The correct answer is B because dendritic cells are not only found in lymph nodes but also in tissues. These cells are antigen-presenting cells that capture and present antigens to T cells. A, C, and D are true statements about dendritic cells: A) They are found in tissues, C) They express high levels of MHC molecules for antigen presentation, and D) They are best at activating naive T cells due to their ability to prime adaptive immune responses.
Which of the following is not considered a virulence factor?
- A. Flagella
- B. Effector proteins manipulating host actin cytoskeleton
- C. Toxins
- D. Peptidoglycan
Correct Answer: D
Rationale: The correct answer is D: Peptidoglycan. Peptidoglycan is a structural component of bacterial cell walls and does not directly contribute to the pathogenicity or virulence of the bacterium. Flagella aid in motility and colonization, effector proteins manipulate host cells, and toxins damage host tissues, all of which are virulence factors. Peptidoglycan is essential for maintaining cell shape and integrity but does not directly enhance the ability of the bacteria to cause disease.
Which of the following statements is NOT true? The SARS coronavirus
- A. Caused an epidemic in 2003 that registered 10% mortality rate
- B. Caused an acute infection of the lungs classified as acute respiratory distress syndrome
- C. Is also the causal agent of MERS (Middle East Respiratory Syndrome)
- D. Is thought to have been transmitted from bats to civets and from civets to humans
Correct Answer: C
Rationale: The correct answer is C because the statement that SARS coronavirus is also the causal agent of MERS is false. MERS (Middle East Respiratory Syndrome) is caused by a different coronavirus called MERS-CoV. SARS-CoV caused the 2003 epidemic with a 10% mortality rate, which aligns with statement A. Statement B is correct as SARS-CoV does cause an acute infection of the lungs known as acute respiratory distress syndrome. Statement D is also true as SARS-CoV is believed to have been transmitted from bats to civets and then to humans. Therefore, the incorrect statement is C.
A 21-year-old patient says no one in his family has type 1 diabetes mellitus but he has had it since childhood. He asks how his diabetes was transmitted to him. The nurse should explain to him that this disease is
- A. a single gene disorder
- B. a chromosome disorder
- C. an acquired genetic disorder
- D. a multifactorial genetic disorder
Correct Answer: D
Rationale: Type 1 diabetes is considered a multifactorial genetic disorder influenced by multiple genes and environmental factors rather than being caused by a single gene or chromosome.
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.