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

Cardiac cycle, The term cardiac cycle means one pumping cycle which consist...

The term cardiac cycle means one pumping cycle which consists of contraction (systole) and relaxation (diastole) of both the atria and both ventricles. Both the atria contract at t

State the term - aneurysms, State the term - Aneurysms Aneurysms are va...

State the term - Aneurysms Aneurysms are vascular dilations resulting from localised defects in the elasticity of a vessel. They can be visualised as balloon like expansions of

Explain nucleosides, Nucleosides : compounds formed from a nitrogenousba...

Nucleosides : compounds formed from a nitrogenousbase and  a penstose sugar.

Probability concept of requirements vs risk of deficient, Define Probabilit...

Define Probability concept of requirements vs risk of deficient and excess intake? Figure best illustrates the concept of a requirement for an essential nutrient. The relations

Explain acyclovir, Explain Acyclovir Available in topical, oral, and in...

Explain Acyclovir Available in topical, oral, and intravenous (IV) formulations, acyclovir is used to treat herpes simplex virus (HSV) and varicella-zoster virus (VZV) infectio

Contraindications for beta-blockers, Reversible airways obstructive disease...

Reversible airways obstructive disease, advanced heart block, or episodic decompensation.  Vasodilators Agents that dilate arteriolar smooth muscle and lower peripheral vascu

Why is aids difficult to prevent by vaccination, Q. Why is AIDS difficult t...

Q. Why is AIDS difficult to prevent by vaccination? It is not easy to produce a vaccine against AIDS because the HIV is a highly mutant virus. In approximately every replicatio

Give a specific example for epithelial, PROVIDE a specific example for epit...

PROVIDE a specific example for epithelial and connective tissues, how the arrangement of cells helps with tissue functioning?

What is meant by saturation or unsaturation of oils and fats, What is meant...

What is meant by saturation or unsaturation of oils and fats? When it is said that a triglyceride is saturated it means that in its molecule the carbon chain is bound in its ma

Explain the riboflavin content of rbc - riboflavin, Explain the Riboflavin ...

Explain the Riboflavin content of RBC - Riboflavin? The erythrocyte glutathione reductase assay, with an activity coe cient (AC) expressing the ratio of activities in the prese

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