Which one of the following is monoecious?

Options

A. Pinus
B. Date palm
C. Marchantia
D. Cycas

Answer

To determine which of the given options is monoecious, we can follow these steps:

### Step 1: Understand the Definitions
- **Monoecious**: A plant species that has both male and female reproductive structures on the same individual. This means that a single plant can produce both male and female flowers.
- **Dioecious**: A plant species where male and female reproductive structures are on separate individuals. This means that one plant will have only male flowers and another plant will have only female flowers.

### Step 2: Analyze Each Option
1. **Pinus**: This is a genus of coniferous trees that are monoecious, meaning they have both male and female cones on the same plant.
2. **Date Palm**: This species is dioecious, meaning that there are separate male and female plants.
3. **Markantia**: This is a genus of liverworts that is also dioecious, having separate male and female plants.
4. **Cycus**: This is a genus of cycads that is dioecious, meaning male and female reproductive structures are found on different plants.

### Step 3: Identify the Monoecious Plant
From the analysis above, we can see that:
- **Pinus** is the only plant listed that is monoecious.

### Conclusion
The correct answer is **Option 1: Pinus**.

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