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

The correct answer is Option (2) → Pollen Grains

Option (1) Microspore mother cells — Incorrect. These diploid cells of the anther divide by meiosis to form microspores. They come before the male gametes and do not carry them.

Option (2) Pollen Grains — Correct. A pollen grain is the male gametophyte. Its generative cell divides to form two male gametes, either before the pollen is shed or later in the pollen tube. The pollen grain carries them to the stigma.

Option (3) Anthers — Incorrect. The anther is the part of the stamen where pollen grains are made. It stays on the flower and is not carried to the pistil.

Option (4) Megaspore mother cells — Incorrect. This cell in the ovule forms the megaspores, which lead to the female gametophyte (embryo sac).

NCERT Extract:
Stamen, Microsporangium and Pollen Grain – “… When the pollen grain is mature it contains two cells, the vegetative cell and generative cell (Figure 1.5b). 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).”

Figure 1.5 (a) Enlarged view of a pollen grain tetrad; (b) stages of a microspore maturing into a pollen grain