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

Myocardial contractility, Inspiration decreases the pressure in the central...

Inspiration decreases the pressure in the central veins and thus increases the pressure gradient between the peripheral and central veins thus augmenting venous return. Skeletal mu

How does the male gamete penetrate the egg cell, Q. How does the male gamet...

Q. How does the male gamete penetrate the egg cell? How does the female gamete protect itself from the entrance of more gametes after the entrance of the first sperm cell? The

Bacteria and archaea been placed in a seperate domain, Why have bacteria an...

Why have bacteria and archaea been placed in a seperate domain?

What are the two divisions of the autonomic nervous system, Q. What are the...

Q. What are the two divisions of the autonomic nervous system? The autonomic nervous system is divided into the parasympathetic nervous system and the sympathetic nervous syste

Mechanical valves, Mechanical Valves They are made of a combination o...

Mechanical Valves They are made of a combination of metal alloys, pyrolite carbon and dacron. Types of Mechanical Valves Caged-ball Valve (Star-Edwards) A me

Explain the interaction of vitamin a with proteins, Explain the interaction...

Explain the interaction of vitamin a with Proteins? Proteins: The protein status of an individual influences vitamin A status and transport because an inadequate protein intake

Symptoms of ulcerative colitis, Q. Symptoms of ulcerative colitis? As d...

Q. Symptoms of ulcerative colitis? As discussed in the case study above, the common symptoms are: 1. Mild abdominaI discomfort, an urgent need to defecate several times a da

Explain the hydration properties of proteins, Hydration Properties  Gen...

Hydration Properties  General conformation of individual proteins in solution is largely dependent on the interaction with water.  The progressive hydration of proteins startin

Explain structure-activity relationships, Structure-activity relationships ...

Structure-activity relationships Structure-activity relationships may be useful to increase the weight-of-evidence or human health hazards identification. Where classes of comp

Determine the uses of electrical recording - brain function, Determine the ...

Determine the uses of Electrical Recording - Brain function We can also learn about brain function by recording its electrical activity. In electroencephalography (EEG) and the

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