Obturator - ovule, Biology

Assignment Help:

Obturator - Ovule

An obturator is an outgrowth of the placenta or funicle or integument or style near the micropyle. It is presumed to guide the pollen tube to the micropyle. This tissue is either composed of thin-walled compact tissue or it is made up of loose hairy outgrowths. The cells of the obturator at the ultra structural level, show dense cytoplasm containing a copious number of ER, dictyosomes, and vesicles. The cells of the obturator produce a surface exudate and provide mechanical and chemical guidance to the growing pollen tube.

323_Obturator.png

Figure:  Obturator in Tetragonia tetragonioides


Related Discussions:- Obturator - ovule

What are risk factors for diseases, What are risk factors for diseases? ...

What are risk factors for diseases? Risk factors for a disease are everything that contributes to enhance the risk of the disease to appear. For instance, for most cardiovascul

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

Viral genome, describe the different types of genomes that viruses can have...

describe the different types of genomes that viruses can have

Explain the economics in nutrition, Explain the Economics in Nutrition? ...

Explain the Economics in Nutrition? We mentioned earlier that nutritional problems affect the productivity of the individual, which, in turn affects the productivity of the nat

How do placental mammals reproduce, How do placental mammals reproduce? ...

How do placental mammals reproduce? Placental mammals reproduce sexually, they have internal fecundation and they are viviparous, i.e., their embryo creates within the mother's

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

Embryology, Explain the gradient theoryof experimental embryology

Explain the gradient theoryof experimental embryology

Zoology of Protozoa, How does the metachronal waves form in the ciliary row...

How does the metachronal waves form in the ciliary row of protozoa ? Explain the cilia beating mechanism associates with it.

Illustrate spoilage of milk and milk products, Q. Illustrate Spoilage of Mi...

Q. Illustrate Spoilage of Milk and Milk Products? Milk is a wholesome food and so it is generally consumed in its basic form or with the addition of a beverage supplement. Mil

What are the valves of the venous system, What are the valves of the venous...

What are the valves of the venous system? What is their function? The valves of the venous system are structures within the veins that permit blood to flow only in the normal w

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