Which of the following is a pathogenic form of Entamoeba histolytica?

Options

A. Quadrinucleate cyst
B. Binucleate cyst
C. Minuta form
D. Magna form

Answer

To determine the pathogenic form of Entamoeba histolytica, we can follow these steps:

### Step 1: Understand the Organism
Entamoeba histolytica is a protozoan parasite that causes amoebiasis in humans. It is important to recognize that this organism has two distinct forms.

**Hint:** Identify the two forms of Entamoeba histolytica and their characteristics.

### Step 2: Identify the Forms
The two forms of Entamoeba histolytica are:
1. **Trophozoite**: This is the active, dividing form of the organism. It is responsible for causing disease in the host.
2. **Cyst**: This is the dormant form that can survive outside the host for extended periods.

**Hint:** Recall which form is responsible for causing disease and which form is more resilient in the environment.

### Step 3: Determine Pathogenicity
Among these two forms, the trophozoite is the pathogenic form. It actively invades the intestinal lining and is responsible for the symptoms associated with amoebiasis. The cyst, while it can infect a new host, is not the form that causes disease directly.

**Hint:** Focus on which form is actively involved in the disease process.

### Step 4: Analyze the Options
Now, let's analyze the options provided in the question:
- Caudronucleate cyst
- Binucleate cyst
- Minuta form (which refers to the cyst)

Both the caudronucleate cyst and binucleate cyst are types of cysts, and the minuta form is another name for the cyst. Therefore, none of these options represent the pathogenic form.

**Hint:** Compare the options with the identified pathogenic form (trophozoite).

### Step 5: Conclusion
The pathogenic form of Entamoeba histolytica is the **trophozoite** (also referred to as the magna form). This is the form that causes disease in humans.

**Final Answer:** The pathogenic form of Entamoeba histolytica is the **trophozoite**.

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