Pollen develops from the mitotic division of microspores. Given this information, to which specific stage in a heterosporous life cycle does pollen belong?

Pollen belongs to the gametophyte stage of a heterosporous life cycle. Here's the step-by-step explanation:

1. In a heterosporous life cycle, there are two types of spores produced: microspores and megaspores.

2. Microspores develop into male gametophytes, while megaspores develop into female gametophytes.

3. The question states that pollen develops from the mitotic division of microspores. This means that pollen is a product of microspores.

4. Since microspores develop into male gametophytes, and pollen is a product of microspores, it follows that pollen is part of the male gametophyte stage in a heterosporous life cycle.

So, the specific stage in a heterosporous life cycle that pollen belongs to is the male gametophyte stage.