Which of these are the carriers of male gametes in some seed plants?

Pollen Grains

The correct answer is Option (2): Pollen Grains

Pollen grains represent the male gametophyte in seed plants, and they play a crucial role in the sexual reproduction of these plants. Here's how this process works.

The male gamete in angiosperms (flowering plants)  is formed within the pollen grain. This process occurs in the anthers of flowers . The male gametophyte contains the male gametes, which are the sperm cells responsible for fertilization.

When the pollen grain is mature it contains two cells, the vegetative cell and generative cell . The vegetative cell is bigger, has abundant food reserve and a large irregularly shaped nucleus. The generative cell is small and floats in the cytoplasm of the vegetative cell. It is spindle shaped with dense cytoplasm and a nucleus. In over 60 per cent of angiosperms, pollen grains are shed at this 2-celled stage. In the remaining species, the generative cell divides mitotically to give rise to the two male gametes before pollen grains are shed (3-celled stage).