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 is the stage of cellular respiration, What is the stage of cellular re...

What is the stage of cellular respiration during which carbon dioxide is liberated? In aerobic cellular respiration the release of carbon dioxide occurs in the transformation o

State the term- hue, State the term- Hue Hue  is the dominant spectral ...

State the term- Hue Hue  is the dominant spectral colour (rainbow) and is related to the wavelength of light. In Munsell system there are five principal hues; red (R), yellow (

What are the terms used in sterilization, Q. What are the terms used in ste...

Q. What are the terms used in sterilization? Sterilization: It is defined as freeing the object or substance from all life of any kind. It is defined alternatively as the

Etiology of constipation, Q. Etiology of constipation? The etiology and...

Q. Etiology of constipation? The etiology and management of two distinct disorders of the bowel viz., diarrhoea and constipation. We small continue our discussion on certain ot

Which term describes study of animal behaviour, Which of the below terms de...

Which of the below terms describes study of animal behavior based on comparisons, observation of patterns, and consideration of environmental adaptations? Is it: a) Ethology (p

What are varices, What are varices? Why are they more common in the inferio...

What are varices? Why are they more common in the inferior limbs? Varix means abnormal enlargement of veins. Varices happen when excessive pressure against the normal blood fl

When the plant transpiration increases, When air humidity is high does the ...

When air humidity is high does the plant transpiration increase or lower? When air humidity is high transpiration diminishes. As transpiration is a simple diffusion process it

Class pycnogonida of phylum arthropoda, Class Pycnogonida of Phylum Arthrop...

Class Pycnogonida of Phylum Arthropoda Measures generally 3-4 mm; body chiefly made up of cephalothorax, abdomen being very small; generally four pairs of walking legs; long p

Why the rate of photosynthesis does increases, Why the rate of photosynthes...

Why the rate of photosynthesis does increases, peak, and then reduces as temperature increases? Increasing the temperature initially accelerates the many chemical reactions in

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