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

Define selectivity - terminologies used in chromatography, Define Selectivi...

Define Selectivity - terminologies used in chromatography? Selectivity is a measure of preference a stationary phase shows for one solute over another and is expressed as:

Nutrition, Nutrition, Feeding, Digestion All organisms require a fairl...

Nutrition, Feeding, Digestion All organisms require a fairly steady supply of nutrient materials from the environment to obtain energy in order to stay alive. The animals are

Procedure of radiographic template, Procedure of radiographic template ...

Procedure of radiographic template It is very similar to a flasking procedure. Mix slow setting irreversible hydrocolloid (alginate) with cold water (to gain more working ti

Spinal cord sectioned at the cervical level, Q. How is it explained that a ...

Q. How is it explained that a person with the spinal cord sectioned at the cervical level is still able to perform the patellar reflex? The arch reflex depends only on the inte

Spermatogonia, Spermatogonia Spermatogonia are the youngest germ cells...

Spermatogonia Spermatogonia are the youngest germ cells from which spermatozoa proliferate. These lie next to the basement membrane and undergo series of mitotic divisions lea

What are the symptoms causes of fever, During a fever in a human, A. sh...

During a fever in a human, A. shivering can happen when the actual body temperature is higher than the set point for body temperature during the fever. B. the control system

Protozoa , lest the characteristics of Protozoa

lest the characteristics of Protozoa

How many of each type of core histone, How many of each type of core histon...

How many of each type of core histone would it take to wrap the entire human genome into nucleosomes? How has evolution solved the problem of producing such a large number of prote

Complete blood count, One may find leucocytosis with predominant polymorpho...

One may find leucocytosis with predominant polymorphonuclear cellular response in patients of ARF in presence of acute some throat. Throat Culture When patient presents as AR

What functions performed by vitamin and mineral for athletes, What function...

What functions performed by Vitamin and Mineral for athletes? Vitamins and minerals perform the same essential functions for athletes and non-athletes alike. However, owing t

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