Botany and Plant Science

The flowers wherein both the sex-organs, that is, the stamen and the pistil are present is called the bisexual or the hermaphroditic flowers. Those flowers wherein, only one of the sex-organ is present and the other is rudimentary absent, are called uni-sexual flowers. These can be pistillate when only pistil is present and can be staminate when only stamen is present.

• Hibiscus, Rose, and Datura have bisexual flowers with both stamens and carpel.
• Papaya has unisexual flowers, male flowers, and female flowers are on separate plants.
• So, the correct answer is 'Papaya'.

Apogamy is the development of a sporophyte from the gametophyte without the fusion of gametes (syngamy).

In angiosperms, the male gametophyte (pollen grain) is highly reduced and does not contain prothallial cells, unlike the male gametophytes of gymnosperms or pteridophytes.

A crassinucellate ovule is one in which the nucellus is massive and well-developed, typically resulting from the division of the primary parietal cell.

When calyx and corolla arise from upper side of ovary it is called epigyny, Ovary is inferior and flower is epigynous.

Flowering plants (angiosperms) have a highly reduced male gametophyte that lacks prothallial cells entirely. This is a key difference from gymnosperms.

In the angiosperm male gametophyte, the generative cell undergoes mitosis to produce two male gametes (sperm cells).

The male gamete in angiosperms is typically small, non-vacuolate, and contains a relatively thin cytoplasm compared to the large, nutrient-rich oosphere (egg cell). Since all these characteristics are accurate, the correct choice is all the above.

In angiosperms, the mature male gametophyte (pollen grain) undergoes mitosis to produce two non-motile male gametes. These gametes are involved in double fertilization.

The microspore is the first cell of the male gametophyte generation in angiosperms. It develops into the pollen grain, which constitutes the male gametophyte.

Each microspore mother cell (MMC) undergoes meiosis to produce 4 microspores. Each microspore then develops into a pollen grain containing 2 male gametes. Thus, 16 MMC produce 16 * 4 = 64 microspores, which in turn produce 64 * 2 = 128 male gametes.

Xenia refers to the effect of pollen on the endosperm, while metaxenia refers to the effect of pollen on maternal tissues outside the embryo sac. Both phenomena involve the influence of pollen on seed or fruit characteristics.

Sporopollenin is an extremely resistant organic polymer that forms the outer layer of the pollen wall, known as the exine.

In the majority of angiosperms (monosporic development), the functional megaspore is the one located at the chalazal end, which is the fourth one from the micropylar end in a linear tetrad.