Okay, let's tackle this question. The question is about endotoxins and where they are part of the cell wall. The options are missing, but the correct answer is supposed to be one of them. I need to figure out what the possible options could be and then explain why the correct one is right and the others wrong.

First, I remember that endotoxins are components of Gram-negative bacteria. They are part of the outer membrane, specifically in the cell wall. The key structure here is the lipopolysaccharide (LPS) layer. So the correct answer should be Gram-negative bacteria.

Now, the options might include Gram-positive bacteria, maybe some specific bacteria like E. coli, or other structures like peptidoglycan. Wait, the question is asking which bacteria's cell wall contains endotoxins. So the correct answer would be Gram-negative bacteria in general. However, sometimes the question might list specific examples like E. coli, Pseudomonas, etc. But since the question is about the cell wall structure, the answer is Gram-negative bacteria.

The wrong options could be Gram-positive, Gram-negative cell wall, maybe peptidoglycan, or other structures. Wait, the question says "outer poion" which is likely a typo for "outer portion". So endotoxins are in the outer membrane of Gram-negative cell walls. Gram-positive bacteria have a thick peptidoglycan layer but no outer membrane with LPS. So if the options are Gram-positive vs Gram-negative, then Gram-negative is correct.

For the clinical pearl, it's important to remember that endotoxins trigger the immune response in sepsis. So when Gram-negative bacteria are lysed, endotoxins are released causing inflammation.

Putting it all together, the correct answer is Gram-negative bacteria. The other options are either Gram-positive, parts of the cell wall without endotoxins, or other structures. So the explanation should cover these points.

**Core Concept**
Endotoxins are lipopolysaccharides (LPS) embedded in the **outer membrane** of **Gram-negative bacterial cell walls**. They trigger innate immune responses via TLR4 activation, leading to systemic inflammation in sepsis.

**Why the Correct Answer is Right**
Gram-negative bacteria (e.g., *E. coli*, *Pseudomonas*) possess an outer membrane containing LPS, which acts as an endotoxin. During bacterial lysis, LPS is released, activating macrophages to secrete cytokines like TNF-α and IL-1β. This drives fever, hypotension, and multiorgan dysfunction in septic shock.

**Why Each Wrong Option is Incorrect**
**Option A:** Gram-positive bacteria lack an outer membrane and instead have thick peptidoglycan with teichoic acids—*no endotoxins*.
**Option B:** Peptidoglycan is a structural component of both Gram-positive and Gram-negative cell walls but *does not contain endotoxins*.
**Option C:** Mycobacteria have a unique cell wall with mycolic acids, not LPS.
**Option D:** Fungi lack bacterial LPS entirely.

**Clinical Pearl / High-Yield Fact**
Remember: **"Gram-negative = LPS = endotoxin."** In se

✓ Correct Answer: B. Gram-negative bacteria