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

Human lungs, Human lungs A pair of spongy, elastic and bag like stru...

Human lungs A pair of spongy, elastic and bag like structures of lungs is present in the chest cavity, one on either side of the heart. Lungs are enclosed by a double lay

Pneumonia, P n e u mo n i a It is inflammation of pulmonary pare...

P n e u mo n i a It is inflammation of pulmonary parenchyma, usually accompanied by inflammation of bronchioles, and is characterized by cough, increased respiratory rat

Nutrition affecting the growth of microorganism, Q. Can Nutrition affecting...

Q. Can Nutrition affecting the growth of microorganism? Ans. Food is food to humans and microbes - be it carbohydrates, proteins or fats. The nutritional requirements of b

Ovipary, Ovipary, Vivipary and Ovovivipary In each case of external a...

Ovipary, Vivipary and Ovovivipary In each case of external and in some cases of internal fertilisation, development of the fertilized egg (zygote) occurs outside the mother's

Determine the steps in surgical therapy, Determine the steps in surgical th...

Determine the steps in surgical therapy a) The first step in surgical therapy is to reflect the tissue and degranulate the defect. b) It is followed by exposing and treating

Explain the programmed senescence theory of ageing, Define senescence Expla...

Define senescence Explain the 'programmed senescence theory' of ageing.

Vertebrate eye - adult eye, Vertebrate Eye - Adult Eye There are no m...

Vertebrate Eye - Adult Eye There are no main differences in the structure or composition of the eyes among different vertebrates. This should be clear to you from the diagram

Cytokinins and Cell Division, α - amylase activity by GA 3 - Dormancy ...

α - amylase activity by GA 3 - Dormancy Of the enzymes required for the digestion of starch α-amylase appears immediately after the start of germination. It was found that

Determine the implant insertion, Implant insertion The technique for in...

Implant insertion The technique for insertion of the implant depends largely upon the system being used. In general, the final bone preparation site diameter is slightly smalle

Define the phytate and protein interaction, Define the Phytate and Protein ...

Define the Phytate and Protein Interaction? You may be more familiar with phytate's role in mineral absorption. However phytates also bind with starch and protein. Depending on

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