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

Defective extra-preputial protrusion of the penis, Defective extra-preputia...

Defective extra-preputial protrusion of the penis This defect is a result of hypoplasia or a defective penile erection due to a congenital mucosal fold – the frenulum - betwee

What do you mean by trichomoniasis, Q. What is trichomoniasis? Why is it cl...

Q. What is trichomoniasis? Why is it classified as an STD? The Trichomoniasis is an extra-intestinal protozoan infection caused by the Trichomonas vaginalis, a flagellate proto

Anaphase, Anaphase This  phase is of shortest duration. It  begins  wit...

Anaphase This  phase is of shortest duration. It  begins  with  a sudden  separation  of the two chromatids of each   due  to splitting   of its centromere and  then a slow mov

Explain states of matter, Q. Explain States of matter Ans. Chemistry de...

Q. Explain States of matter Ans. Chemistry deals with the nature and composition of matter - anything that occupies space and has mass, and the changes which it undergoes. Matt

Explain adverse effects of foscarnet, Explain Adverse Effects of foscarnet ...

Explain Adverse Effects of foscarnet  Renal dysfunction often develops during treatment with foscarnet and is usually reversible, but renal failure requiring dialy sis may occu

Platyhelminthes, tell me the general characters of monopisthocotylea

tell me the general characters of monopisthocotylea

Principles of haccp, Principles of HACCP A) Determine the  Critical  Co...

Principles of HACCP A) Determine the  Critical  Control  Points  (CCPs) B) Establish  Critical Limit(s) C) Establish a  System  to  Monitor Control of the  CCP D) Esta

Define general nutritional functions of minerals, Define General Nutritiona...

Define General Nutritional Functions of Minerals? We hear and talk about minerals almost everyday with regards to maintaining good health. But what are minerals and what functi

Define role of vitamin a in controlling gene expression, Define role of Vit...

Define role of Vitamin A in controlling gene expression? Vitamin A as retinoic acid has widespread effects on the synthesis of a variety of important proteins. These diverse ef

Issues to be discussed while counselling a diabetic patient, Q. Issues to b...

Q. Issues to be discussed while counselling a diabetic patient ? Issues to be discussed · Counselling at Diagnosis · Diabetes is Controllable · Counselling for Day

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