Ascaris is

Options

A. Monogenetic
B. Digenetic
C. Common parasite of large intestine
D. Both (1) and (3)

Answer

**Step-by-Step Solution:**

1. **Identify the Organism**: Ascaris is commonly known as the roundworm.

2. **Classify the Organism**: It belongs to the phylum Nematoda, also referred to as Ascalmyntes.

3. **Determine the Habitat**: Ascaris is an endoparasite, specifically found in the small intestine of its host, which is typically humans, especially children.

4. **Understand the Life Cycle**: Ascaris has a monogenetic life cycle, meaning it completes its entire life cycle within a single host (humans).

5. **Evaluate the Options**:
- **Option 1**: They are monogenetic (Correct, as they complete their life cycle in one host).
- **Option 2**: They are digenetic (Incorrect, as they do not require two hosts).
- **Option 3**: They are common parasites of the large intestine (Incorrect, as they inhabit the small intestine).
- **Option 4**: This option is also incorrect based on the previous evaluations.

6. **Conclusion**: The correct answer is Option 1, which states that Ascaris is monogenetic.