What are pollen grains known to contain?

Pollen grains are known to contain the male gametophyte of seed plants. This structure is essential for reproduction, as it carries the male gametes (sperm cells) necessary for fertilization. When pollen grains land on the stigma of a compatible flower, they germinate and form a pollen tube that delivers the sperm to the ovule, where fertilization occurs.

The male gametophyte within the pollen grain is highly specialized for this function, enabling the process of sexual reproduction in plants. It’s important to note that pollen grains do not contain female gametophytes, plant roots, or flower petals, which are separate structures with distinct roles in the life cycle of plants.