Which organisin is considered to be a common anceator of plants and animals?

Options

A. Utricularia
B. Euglena
C. Paramoecium
D. Chlamydomonas

Answer

To determine which organism is considered to be a common ancestor of plants and animals, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Common Ancestors**:
- A common ancestor is an organism from which two or more different species have evolved. In the context of plants and animals, we are looking for an organism that shares characteristics of both kingdoms.

2. **Analyzing the Options**:
- The options provided are Eutrychularia, Euclina, Pyramidium, and Chlamydomonus. We need to evaluate each option to see which one could be a common ancestor.

3. **Identifying Characteristics**:
- **Eutrychularia**: This is a plant and exhibits only plant characteristics.
- **Pyramidium**: This is a protozoan, which is an animal-like organism.
- **Chlamydomonus**: This is a type of green algae, which has characteristics of plants but is still a single-celled organism.
- **Euclina**: This is a protist that has both plant-like and animal-like characteristics. It can photosynthesize like plants (due to chloroplasts) and can also consume food like animals.

4. **Conclusion**:
- Among the options, **Euclina** is the organism that exhibits traits of both plants and animals, making it a strong candidate for a common ancestor. It has features that link both kingdoms, such as the ability to photosynthesize and the absence of a cell wall, which is characteristic of animals.

5. **Final Answer**:
- Therefore, the correct answer is **Euclina**.