Which compounds produced by microorganisms can cause fever in humans and can withstand autoclaving?

Correct Answer: D

Rationale: The correct answer is D, peptidoglycan. Peptidoglycan is a component of bacterial cell walls that can trigger fever in humans. It is a sturdy molecule that can withstand autoclaving. A: Endotoxin is a component of the outer membrane of Gram-negative bacteria, not resistant to autoclaving. B: Lipid A is the toxic component of endotoxin, not resistant to autoclaving. C: Lipopolysaccharide is the major component of the outer membrane of Gram-negative bacteria, not resistant to autoclaving.

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.

Correct Answer: C

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