Fresh water photosynthetic protists of stagnant water shows dual behaviour in :

Options

A. nutrition and reproduction
B. respiration and spore formation
C. nutrition and movement
D. locomotion and respiration

Answer

To solve the question regarding the dual behavior of freshwater photosynthetic protists found in stagnant water, we will analyze the options provided and determine which one correctly describes the dual behavior.

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the dual behavior exhibited by freshwater photosynthetic protists in stagnant water. Dual behavior typically refers to two different characteristics or functions that these organisms can perform.

2. **Analyzing the Options**:
- **Option 1: Nutrition and Reproduction**: This option suggests that the dual behavior is related to how these organisms obtain nutrients and how they reproduce. While it is true that some protists can exhibit mixotrophic nutrition (both autotrophic and heterotrophic), the reproduction aspect does not typically reflect a dual behavior.
- **Option 2: Respiration and Spore Formation**: This option implies that the dual behavior is related to how these organisms respire and form spores. However, respiration is a fundamental process that does not exhibit dual behavior in the context of this question.
- **Option 3: Nutrition and Movement**: This option indicates that the dual behavior involves how these organisms obtain nutrients and how they move. This is correct because many freshwater protists can perform mixotropic nutrition (both photosynthesis and absorption of organic matter) and exhibit various types of movement (flagellar, ciliary, or amoeboid).
- **Option 4: Locomotion and Respiration**: This option suggests that the dual behavior involves locomotion and respiration. While locomotion is a behavior, respiration does not typically reflect a dual behavior in this context.

3. **Identifying the Correct Answer**: Based on the analysis, Option 3 (Nutrition and Movement) is the correct answer as it accurately describes the dual behavior of freshwater photosynthetic protists in stagnant water.

### Final Answer:
The correct answer is **Option 3: Nutrition and Movement**.

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