[A]: Gramineoos type of stomata are found in Gramineae and Cyperaceae.
[R]: Gramineous stoma1a are dumbbell shape

Options

A. If both A and R are true and R is the correct explanation of A
B. If both A and R are true but R is not the correct explanation of A
C. If A is true and R is false
D. If both A and R are false

Answer

To solve the question regarding the assertion and reason about Gramineous type of stomata, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Assertion and Reason**:
- Assertion (A): Gramineous type of stomata are found in Gramineae and Cyperaceae.
- Reason (R): Gramineous stomata are dumbbell-shaped.

2. **Understand the Families Mentioned**:
- The family Gramineae is also known as Poaceae, commonly referred to as the grass family.
- The family Cyperaceae consists of plants known as sedges.

3. **Function of Stomata**:
- Stomata are openings in the plant's epidermis that facilitate gas exchange (CO2 and O2) and transpiration.

4. **Structure of Gramineous Stomata**:
- Gramineous stomata are characterized by their unique structure, which includes two guard cells surrounding a stomatal aperture and subsidiary cells.
- The shape of these guard cells is typically described as dumbbell-shaped.

5. **Evaluate the Assertion**:
- The assertion states that Gramineous stomata are found in both the Gramineae (Poaceae) and Cyperaceae families. This is true as both families are known to possess this type of stomata.

6. **Evaluate the Reason**:
- The reason states that Gramineous stomata are dumbbell-shaped. This is also true based on the structural characteristics of the stomata in these families.

7. **Conclusion**:
- Since both the assertion and the reason are true, and the reason correctly explains the assertion, we can conclude that the correct answer is that both statements are true and the reason is a correct explanation of the assertion.

### Final Answer:
Both the assertion and reason are true, and the reason provides a correct explanation for the assertion.

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