Identify the correct sequence of structure of androecium in chronological order of development .

Options

A. Sporogenous tissue `rarr` pollen grain `rarr` microspore tetrad `rarr` male gametes.
B. Sporogenous tissue `rarr` microspore tetrad `rarr` pollen grain`rarr` male gametes.
C. pollen grain `rarr` Sporogenous tissue`rarr` microspore tetrad `rarr` male gametes.
D. microspore tetrad `rarr` Sporogenous tissue `rarr` pollen grain`rarr` male gametes.

Answer

To solve the question regarding the correct sequence of the structures of the androecium in chronological order of development, we need to understand the process of male gamete formation in flowering plants. Here’s a step-by-step breakdown:

### Step 1: Understanding Androecium
- The androecium is the male reproductive part of a flower, consisting of stamens, which produce pollen grains. The development of male gametes occurs within this structure.

### Step 2: Starting Point - Sporogenous Tissue
- The process begins with the **sporogenous tissue**. This tissue is composed of pollen mother cells (microsporocytes) that will undergo meiosis to form microspores.

### Step 3: Formation of Microspore Tetrad
- The pollen mother cells divide meiotically to produce a **microspore tetrad**. This tetrad consists of four microspores, but typically, three of these will degenerate, leaving one functional microspore.

### Step 4: Development of Pollen Grain
- The remaining functional microspore develops into a **pollen grain**. This is the structure that will eventually carry the male gametes.

### Step 5: Formation of Male Gametes
- Finally, within the pollen grain, the microspore undergoes mitosis to form **male gametes**. Each pollen grain typically contains two male gametes.

### Conclusion
Based on the above steps, the correct chronological order of development in the androecium is:
1. Sporogenous tissue
2. Microspore tetrad
3. Pollen grain
4. Male gametes

### Answer
The correct option is: **Sporogenous tissue, Microspore tetrad, Pollen grain, Male gametes.**

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