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

Describe about sex determination systems, Besides the XY system are there o...

Besides the XY system are there other sex determination systems? Some animals have a sex determination system dissimilar from the XY system. The X0 system is the sex determi

Protozoan , justify the claim that paramecium is the highly evolved protozo...

justify the claim that paramecium is the highly evolved protozoan basing on the morphological and physiological features .

How vitamins & minerals work together with nutrients in food, How Vitamins ...

How Vitamins and minerals work together with nutrients in food? Vitamins and minerals work together with nutrients in food. While antioxidant vitamins E and C and beta-carotene

Define role of public nutritionist in health care delivery, Define the Role...

Define the Role of Public Nutritionist in Health Care Delivery? It is clearly evident from the foregoing discussion that nutrition is an important, though not the only, determi

Explain changes in mental development of infants, Explain Changes in Mental...

Explain Changes in Mental Development of Infants? There is evidently an increase in the brain size. There is a rapid increase in the number of brain cells in the first 5-6 mont

Explain insect resistant crops in evolutionary way, Explain Insect resistan...

Explain Insect resistant crops in Evolutionary way Insects are a natural selection pressure so plants resistant to certain insects could have an evolutionary advantage (in

Diagnostic procedures for acute glomerulonephritis, Diagnostic Procedures ...

Diagnostic Procedures     Taking Clinical history    Urine analysis    Blood sample  for  estimation  of blood urea nitrogen    Antistrepto lysine  (ASO) titer

Digestive system - salivary glands, SALI V A R Y GLAND - These are ...

SALI V A R Y GLAND - These are compound - Alveolar, tubular glands made up of columnar / cuboidal epithelium. Saliva is manufactured in them. In mammals these are pai

Triple fusion, Triple Fusion The fusion process between the other male...

Triple Fusion The fusion process between the other male gamete and the secondary nucleus follows the same pattern as syngamy. In most plants, the polar nuclei are only partial

Define diagnostic criteria for bulimia nervosa, Define Diagnostic Criteria ...

Define Diagnostic Criteria for Bulimia Nervosa? 1. Recurrent episodes of binge eating. An episode of binge eating is characterized by both of the following a) Eating, in a d

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