Nokea
Elaborating on Jenner's observations, who is considered to have created the first "attenuated" vaccine
- A. Louis Pasteur
- B. Robert Koch
- C. Ilya Metchnikoff
- D. Adolf Von Behring
Correct Answer: A
Rationale: The correct answer is A: Louis Pasteur. He is considered to have created the first "attenuated" vaccine based on his work with the rabies vaccine in the 1880s. Pasteur's method involved weakening the virus to make it less harmful while still eliciting an immune response. Other choices are incorrect because:
B: Robert Koch is known for his contributions to microbiology and germ theory, not for creating the first attenuated vaccine.
C: Ilya Metchnikoff is known for his work on immunology and phagocytosis, not for developing the first attenuated vaccine.
D: Adolf Von Behring is known for his research on diphtheria antitoxin, not for creating the first attenuated vaccine.
You may also like to solve these questions
Which of the following is a molecule that inhibits T cell activation, is highly expressed in Tregs and is used in a recombinant (synthetic) form to treat some autoimmune diseases?
- A. CD86
- B. CTLA-4
- C. MHC class II
- D. CD4
Correct Answer: B
Rationale: The correct answer is B: CTLA-4. CTLA-4 inhibits T cell activation by binding to CD80/CD86 on antigen-presenting cells, preventing the co-stimulatory signal required for T cell activation. It is highly expressed in Tregs, which suppress immune responses. Recombinant CTLA-4 (e.g., abatacept) is used to treat autoimmune diseases by blocking T cell activation.
Explanation for other choices:
A: CD86 is a co-stimulatory molecule that activates T cells, not inhibits them.
C: MHC class II molecules present antigens to T cells, they do not inhibit T cell activation.
D: CD4 is a co-receptor that helps T cells recognize antigens presented by MHC class II molecules, it does not inhibit T cell activation.
The annotation C refers to which DNA component?
- A. Vector DNA
- B. Plasmid DNA
- C. Chromosomal DNA
- D. Recombinant DNA
Correct Answer: C
Rationale: The correct answer is C: Chromosomal DNA. Chromosomal DNA refers to the DNA found in the chromosomes of an organism's nucleus, carrying the majority of its genetic information. In molecular biology, the annotation C typically refers to the chromosomal DNA of the organism being studied. Plasmid DNA (choice B) and vector DNA (choice A) are extrachromosomal DNA elements that are separate from the chromosomal DNA. Recombinant DNA (choice D) is a DNA molecule formed by combining DNA from different sources, which can include chromosomal, plasmid, or vector DNA. Therefore, the correct choice is C as it specifically refers to the chromosomal DNA component.
Select the correct number of statements that are true.
- A. Only 1 and 3 are correct.
- B. Only 2 and 4 are correct.
- C. Only 3 and 4 are correct.
- D. All of the above are correct.
Correct Answer: A
Rationale: The correct answer is A. Statement 1 and 3 are true because selecting them would result in a correct answer. Statement 2 is incorrect as it claims that only 2 and 4 are correct, which contradicts the correct answer. Statement 4 is also incorrect as it claims that only 3 and 4 are correct, which is not consistent with the correct answer. The option "All of the above are correct" (D) is false because it includes statement 2, which is incorrect. Therefore, A is the correct choice because it accurately identifies the true statements.
What type of diseases does the immune system primarily defend against?
- A. Autoimmune diseases
- B. Infectious diseases
- C. Neurological disorders
- D. Cardiovascular diseases
Correct Answer: B
Rationale: The correct answer is B: Infectious diseases. The immune system's main function is to protect the body from foreign invaders such as bacteria, viruses, and parasites. It recognizes and eliminates these pathogens to prevent infections. Autoimmune diseases (A) occur when the immune system mistakenly attacks healthy cells. Neurological disorders (C) and cardiovascular diseases (D) are not primarily defended against by the immune system as they are not caused by external pathogens.
What are the most common immunosuppressive agents used to prevent rejection of transplanted organs?
- A. Cyclosporine, sirolimus, and muromonab-CD3
- B. Prednisone, polyclonal antibodies, and cyclosporine
- C. Azathioprine, mycophenolate mofetil, and sirolimus
- D. Tacrolimus, prednisone, and mycophenolate mofetil
Correct Answer: D
Rationale: Tacrolimus, prednisone, and mycophenolate mofetil are commonly used to prevent organ rejection.