Contractile vacuole is important for excretion in

Options

A. Amoeba
B. Paramecium
C. Euglena
D. Plasmodium

Answer

To solve the question "Contractile vacuole is important for excretion in," we will follow these steps:

### Step 1: Understand the Function of Contractile Vacuole
The contractile vacuole is an organelle found in some unicellular organisms. Its primary function is to expel excess water from the cell, preventing it from bursting (lysing) due to osmotic pressure. This process is crucial for maintaining homeostasis in the cell.

**Hint:** Remember that the contractile vacuole helps regulate water levels in the cell.

### Step 2: Identify the Organisms Listed
The options provided are:
1. Amoeba
2. Paramecium
3. Euglena
4. Plasmodium

**Hint:** Familiarize yourself with the characteristics of each organism to determine which one is most associated with contractile vacuoles.

### Step 3: Classify the Organisms
- **Amoeba**: A unicellular organism that does not primarily use contractile vacuoles for excretion.
- **Paramecium**: A ciliate that possesses a contractile vacuole, which is essential for expelling excess water.
- **Euglena**: A flagellate that has a contractile vacuole, but it is not as prominent as in Paramecium.
- **Plasmodium**: A protozoan that does not have a contractile vacuole and relies on different mechanisms for excretion.

**Hint:** Focus on the specific role of contractile vacuoles in each organism.

### Step 4: Determine the Most Relevant Organism
Among the options, Paramecium is known for having a well-developed contractile vacuole that plays a significant role in excretion and water regulation. This feature is particularly prominent in ciliates.

**Hint:** Identify which organism is primarily associated with the presence of contractile vacuoles.

### Step 5: Conclusion
Based on the analysis, the correct answer is **Paramecium**. It is the organism among the options provided that relies heavily on the contractile vacuole for excretion.

**Final Answer:** The contractile vacuole is important for excretion in **Paramecium**.