Tag: reproductive health

Each microsporocyte (microspore mother cell) undergoes meiosis to produce 4 microspores (pollen grains). Therefore, 4 microsporocytes produce 4 * 4 = 16 pollen grains.

In an amphitropous ovule, the embryo sac is curved into a horseshoe shape, and the micropyle, chalaza, and funicle are brought close together.

The root of a flowering plant is diploid (2n = 24). Gametes are haploid (n), so they contain half the number of chromosomes, which is 12.

In angiosperms, pollen grains are typically shed at either the 2-celled stage (vegetative and generative cell) or the 3-celled stage (vegetative cell and two male gametes).

Endosperm is triploid (3n). Pisum sativum (2n=14, 3n=21), Oryza sativa (2n=24, 3n=36), Nicotiana tabacum (2n=48, 3n=72), Allium cepa (2n=16, 3n=24). Matching: a-v, b-iv, c-i, d-ii.

The exine of a pollen grain is composed of sporopollenin, which is one of the most resistant organic materials known, protecting the pollen from degradation.

The nucellus is a diploid tissue (2n). The microspore mother cell (MMC) is also a diploid cell derived from the sporophytic tissue, so it has the same chromosome number.

In angiosperms, the female gamete is the egg cell, which is located within the embryo sac inside the ovule.

Palynology is the scientific study of pollen grains and spores, both living and fossilized.

An orthotropous ovule is one where the micropyle, chalaza, and funiculus lie in a straight vertical line.