Endothecium - anther wall layers, Biology

Assignment Help:

Endothecium - Anther Wall Layers

The layer of cells lying immediately next to the epidermis is the endothecium, which is responsible for the dehiscence of the anther. It is usually single-layered, but sometimes multilayered as in Nicotiana tabacum. You may recall that the endothecium originates from the PPCs. The endothecium mostly differentiates in the four protuberant or bulging parts of the anther. Sometimes, it also develops near the connective region of the anther. In some plants like Triticale an entire ring of endothecium is present.

1998_Endothecium.png

Figure: (a) Diagrammatic sketch of the transverse section of an anther showing the position of the endothecium (small arrows). Large arrows point to the two dehiscing regions of the anthers showing longitudinal dehiscence. (b) A few endothecial cells enlarged to show the characteristic endothecial thickenings.

The endothecial cells are radially elongated. Their full development is attained by the time the anther is ready to dehisce to discharge the pollen grains. At maturity the endothecial cells can be easily recognized by the presence of fibrous bands. They usually arise from the inner tangential walls. The fibrous bands radiate outwards and upwards ending near the outer wall of each cell. Hence, the inner tangential wall appears thick, whereas the outer tangential wall appears thin. These thickenings contain a high proportion of cellulose and a small amount of pectin.


Related Discussions:- Endothecium - anther wall layers

Three irreversible reactions in the glycolytic pathway, Name the three irr...

Name the three irreversible reactions  in the glycolytic pathway. The three irreversible reactions in the glycolytic  pathway are : Glucose → Glucose-6-phosphate Fructose

What is the mechanism described by darwin, What is the mechanism described ...

What is the mechanism described by Darwin that eliminates species less adapted to environmental conditions? The mentioned mechanism is the natural selection.

Why is ridge mapping required, Why is ridge mapping required and what is it...

Why is ridge mapping required and what is its alternative The selection of the implant diameter apart from the mesiodistal space available also depends on the buccolingual widt

Determine the uni-ocular movements, Determine the Uni-ocular movements ...

Determine the Uni-ocular movements Uni-ocular movements are the movements of  one eye  studied  at  a time. That means, when left  eye is  covered, then movements  of  uncovere

Etiology of diarrhoea, Etiology   The causes of diarrhoea can be classi...

Etiology   The causes of diarrhoea can be classified as follows:  i)  Infectious causes   Viral  : Rota virus, Norwalk and allied viruses, Enterovirus, Influenza virus,

Modern theory in biology, Modern Theory Naturalistic theory: Accordin...

Modern Theory Naturalistic theory: According to this theory Life originated upon our earth spontaneously from nonliving matter. But there are two significant points in this r

Mechanisms of sex determination and dosage compensation, XYY humans are fer...

XYY humans are fertile males. XXX humans are fertile females. What do these observations reveal about the mechanisms of sex determination and dosage compensation?

What are monosaccharides and polysaccharides, What are monosaccharides, oli...

What are monosaccharides, oligosaccharides and polysaccharides? Monosaccharides are normal molecules of carbohydrates that cannot be broken into smaller molecules of other carb

What body system hiv impairs, Given that most AIDS victims die from overwhe...

Given that most AIDS victims die from overwhelming infections or rare types of cancer, what body system do you think HIV (the AIDS virus) impairs?

Determine energy expenditure for climbers, Determine energy expenditure for...

Determine energy expenditure for Climbers? The energy expenditure of 3250 Kcal/ day is reported in climbers to Mt. Everest using doubly labeled water teaching. Out of this, 161

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd