Euglenoid species that have chlorophyll are

Options

A. obligate autotrophs
B. facultative autotrophs
C. facultative heterotrphs
D. obligate heterotrophs

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for the euglinoid species that have chlorophyll. This indicates that we are looking for organisms that can perform photosynthesis.

2. **Identifying Key Terms**: The terms "obligate autotrophs," "facultative autotrophs," "facultative heterotrophs," and "obligate heterotrophs" are crucial to understanding the types of nutritional modes.

3. **Eliminating Options**: Since the question specifies organisms with chlorophyll, we can eliminate the heterotrophic options:
- **Facultative heterotrophs**: These organisms can switch between autotrophy and heterotrophy but are not primarily autotrophic.
- **Obligate heterotrophs**: These organisms cannot perform photosynthesis and rely entirely on other organisms for nutrition.

4. **Understanding Autotrophs**:
- **Obligate autotrophs**: These organisms must obtain energy through photosynthesis or chemical oxidation of inorganic substrates.
- **Facultative autotrophs**: These organisms can perform photosynthesis but can also obtain energy from organic sources when necessary.

5. **Analyzing Euglenoids**: Euglenoids are unique because they possess chlorophyll, allowing them to perform photosynthesis, but they can also absorb nutrients from their environment, making them capable of heterotrophy.

6. **Conclusion**: Given that euglinoids can perform both functions (photosynthesis and nutrient absorption), they are classified as facultative autotrophs. Therefore, the correct answer is **option 2: facultative autotrophs**.