Write down the functions of parts of anatropous ovule
Answers
An anatropous ovule has following parts:
1) outer and inner integument: they are the two layers or envelope covering the anatropous ovule except at the micropyle pole.
2)nucellus: contain cells which nourishes the embryo sac
3) embryo sac: represents female gametophyte which is seven called and eight uncleared structure,
Hope it helps....:)
The ovule is made up of the nucellus, the integuments that form the outermost layer, and the female gametophyte (called an embryo sac in flowering plants), which are found at the very center.
Anatropous
In this case, the ovules become completely inverted during development so that the micropyle lies close to the hilum. The hilum is a scar that marks the point where the seed was attached to the fruit wall by the funicle.
The Nucellus
The nucellus is the largest part of the ovule. It houses the embryo sac as well as nutritive tissue and actually remains present in some flowering plants after fertilization as a source of nutrients for the embyo.
The Integuments
The integument is the tough outer protective layer of the ovule. In the diagrams below we can see that gymnosperms, such as pine trees and spruce trees, usually have one integument in an ovule, so we call them unitegmic. On the other hand, angiosperms, like maples and daisies, typically have two integuments, and we call them bitegmic. The integument encloses the nucellus except for a small gap, which is called the micropyle.
The Female Gametophyte
This is the part of the ovules that contains the gamete-producing sex organs, which are critical for sexual reproduction. The female gametophyte contains a single set of unpaired chromosomes, meaning that it’s haploid. Note that it is commonly called the embryo sac or megagametophyte.