Tag: flowers and fruits

In gymnosperms, the endosperm is formed before fertilization from the female gametophyte, making it haploid. In angiosperms, it is formed after fertilization via triple fusion, making it triploid.

Gingko biloba, commonly called as gingko, is an endangered genus belonging to division Gymnosperm. It is also a living fossil, as it is the sole survivor of a group of trees that belonged to an era of dinosaurs. The trees rich up to 40 meters in height. It is a deciduous conifer because it sheds its leaves annually. It is found in deciduous forests and valleys. 

The endosperm in gymnosperms is part of the female gametophyte, which develops into the endosperm before fertilization occurs.

Gymnosperms typically lack xylem vessels (except in Gnetales) and companion cells (they have albuminous cells instead).

Gymnosperms and angiosperms (like maize) are seed plants that use pollen tubes for fertilization, meaning they do not require external water for the sperm to reach the egg.

Plants that produce seeds but lack flowers and fruits are classified as gymnosperms.

Gymnosperms do not have antheridia; they produce pollen grains (microspores) that develop into male gametophytes.

The defining characteristic of gymnosperms is the presence of 'naked seeds', meaning the seeds are not enclosed in an ovary.

Cycas is a genus of gymnosperms, which are characterized by having naked seeds.

In gymnosperms, the ovules are exposed on the surface of megasporophylls and are not enclosed by an ovary wall, thus they are 'naked'.