Match the following terms (1-6) with their respective meanings (A-F).

Correct Answer: C

Rationale: The correct match for the terms is: 1 - D 2 - C 3 - B 4 - E 5 - A 6 - F Rationale: 1. Term 1 corresponds to definition D, as per choice C. 2. Term 2 matches with definition C, as per choice C. 3. Term 3 aligns with definition B, as per choice C. 4. Term 4 correlates with definition E, as per choice C. 5. Term 5 matches with definition A, as per choice C. 6. Term 6 corresponds to definition F, as per choice C. Summary: - Choice A has incorrect matches for terms 1, 2, 3, 5, and 6. - Choice B has incorrect matches for terms 1, 2, 3, and 4. - Choice D has incorrect matches for terms 1, 2, 4, and 6. Therefore, the correct answer

Correct Answer: A

Rationale: The correct answer is A. A second exposure to an allergen does not lead to the development of autoimmune disorders. The key mechanisms involved in autoimmune disorders are self-tolerance breakdown and immune system attacking self-antigens. Explanation: 1. B: Cross-reaction of antibodies formed against foreign antigens with self-antigens is a possible mechanism for autoimmune disorders. 2. C: Exposure of previously 'hidden' self-antigens to the adaptive immune system can trigger autoimmune responses. 3. D: Mutation followed by the appearance of membrane proteins not previously present can lead to autoimmune disorders, as the immune system may recognize these proteins as foreign. Summary: Choice A is incorrect because a second exposure to an allergen does not cause the immune system to target self-antigens, which is the hallmark of autoimmune disorders. Choices B, C, and D are more plausible mechanisms for the development of autoimmune disorders.

Correct Answer: A

Rationale: Terminal deoxynucleotidyl transferase (TdT) adds nucleotides to the 3' end of DNA fragments in a template-independent manner. This results in the production of fragments with poly A or poly C tails. TdT does not add poly T tails, making option D incorrect. It also does not specifically add only poly C tails (option B) or poly A tails (option C). The addition of poly A or poly C tails by TdT is essential for techniques like DNA sequencing and PCR, where these tails are utilized for downstream applications.

Correct Answer: C

Rationale: The correct answer is C: 5' cohesive ends. Sacl restriction endonuclease cuts DNA at specific recognition sites, leaving single-stranded overhangs called cohesive ends. In this case, Sacl creates 5' overhangs, resulting in fragments with 5' cohesive ends. Blunt ends (option A) have no overhangs, making them incorrect. Options B and D are incorrect as they do not align with the specific characteristic of Sacl restriction endonuclease's cleavage pattern.

Correct Answer: A

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.