**Question:** Which of the following produce both polar and peritrichous flagella?

**Core Concept:** Bacteria and archaea can have various types of flagella, including polar and peritrichous flagella. Polar flagella are found at one end of the cell, while peritrichous flagella are distributed evenly around the cell.

**Why the Correct Answer is Right:**

The correct answer, **Option C: Bacillus subtilis**, is right because it is a bacterium that possesses both polar and peritrichous flagella. In this organism, polar flagella are located at one end of the cell, and the peritrichous flagella are distributed evenly around the cell surface. This dual flagellar arrangement allows Bacillus subtilis to exhibit versatile motility and enhance its ability to navigate various environments.

**Why Each Wrong Option is Incorrect:**

Incorrect options are:

**Option A (Corynebacterium diphtheriae):** This bacterium produces one type of flagella, called lateral flagella, which are not the same as polar and peritrichous flagella. It is known for producing the diphtheria toxin and causing diphtheria disease.

**Option B (Salmonella typhi):** Salmonella typhi is primarily associated with the causation of typhoid fever and does not possess polar and peritrichous flagella like Bacillus subtilis.

**Option D (Mycobacterium tuberculosis):** Mycobacterium tuberculosis is the bacterium responsible for causing tuberculosis and does not have polar and peritrichous flagella; it possesses a unique type of flagella called "bead-like" or "bead-like arrangement of flagella."

**Core Concept:** Flagella are essential appendages in bacteria and archaea, enabling them to move and interact with their environment. Polar flagella are found at one end of the cell, while peritrichous flagella are distributed evenly around the cell surface.

**Why Each Wrong Option is Incorrect:**

Polar flagella are found in bacteria like **Option A (Corynebacterium diphtheriae)** and archaea like **Option D (Mycobacterium tuberculosis)**. Peritrichous flagella are seen in **Option C (Bacillus subtilis)**.

**Why the Correct Answer is Right:**

**Option C (Bacillus subtilis)** is correct because it produces both polar and peritrichous flagella. The polar flagella are arranged at one end of the cell, enabling directional movement, while peritrichous flagella are distributed evenly around the cell surface, allowing the bacterium to move randomly in multiple directions and interact with its environment effectively.

**Clinical Pearls:**

1. Bacillus subtilis is a common inhabitant of the human gastrointestinal tract and skin.
2. The ability to produce both types of flagella allows Bacillus subtilis to efficiently navigate its environment, which is essential for survival and colonization in various niches.
3. Understanding the presence of polar and peritrich