Biology · Sexual Reproduction in Flowering Plants · NEET
Yes. NCERT states plainly: 'Pollen grains represent the male gametophytes.' A microspore matures into a pollen grain, and this whole grain (not a separate structure inside it) is the highly reduced male gametophyte generation of the angiosperm. Do not confuse it with the male gamete — the gamete is produced later by the generative cell.
The vegetative cell is bigger, has abundant food reserve, and a large irregularly shaped nucleus — it later forms the pollen tube (so it is also called the tube cell). The generative cell is small, spindle shaped, has dense cytoplasm and a nucleus, and floats inside the cytoplasm of the vegetative cell — it divides mitotically to form the two male gametes. Remember: big = feeds/carries, small = breeds.
At shedding, most pollen (over 60% of angiosperms) is in the 2-celled stage — one vegetative cell + one generative cell. In the remaining species the generative cell divides mitotically into two male gametes BEFORE shedding, so pollen is shed at the 3-celled stage (one vegetative cell + two male gametes). Both eventually deliver two male gametes; they differ only in WHEN the generative cell divides.
After pollination, during the growth of the pollen tube. NCERT: in plants that shed pollen at the two-celled condition, 'the generative cell divides and forms the two male gametes during the growth of pollen tube in the stigma.' In 3-celled shedders the two male gametes are already present and the pollen tube simply carries them from the beginning.
No. This is a very common NEET trap. The vegetative (tube) cell never divides to form gametes — it only elongates to form the pollen tube and controls its growth. Only the generative cell divides mitotically to produce the two non-motile male gametes.
Two. The single generative cell divides once (mitosis) into two male gametes. Two are needed because of double fertilisation: one male gamete fuses with the egg (syngamy → zygote) and the other fuses with the two polar nuclei (triple fusion → endosperm).
The plant parts which consist of two generations one within the other: (a) Pollen grains inside the anther (b) Germinated pollen grain with two male gametes (c) Seed inside the fruit (d) Embryo sac inside the ovule
Try the real previous-year questions from this chapter — each with the answer and a full solution.
Because after pollination it elongates through the germ pore to form the pollen tube, which grows through the stigma and style to carry the male gametes to the ovule. Its large nucleus is called the tube (vegetative) nucleus.
The vegetative cell is bigger. It has abundant food reserve and a large irregularly shaped nucleus. The generative cell is small, spindle shaped, and floats inside the vegetative cell's cytoplasm.
No. Unlike the flagellated antherozoids of bryophytes and pteridophytes, the two male gametes of angiosperms are non-motile. They are carried passively to the ovule by the pollen tube, so no external water is needed for fertilisation.
Both are haploid (n). The pollen grain develops from a haploid microspore, so all its cells — vegetative cell, generative cell, and the two male gametes formed from it — are haploid.
No. The generative cell is a single cell that DIVIDES mitotically to form the two male gametes. So one generative cell gives rise to two male gametes; it is not itself a gamete.
