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

Chemical stress, Chemical Stress Survival of cells is dependent on car...

Chemical Stress Survival of cells is dependent on carrying out of a set of chemical reactions (metabolic reactions) in a particular order. This results in a net gain in mass a

What is the probability of two individuals, What is the probability of two ...

What is the probability of two individuals (AaBBccDd and aaBbCcDd) having a child with the following genotype AaBBCcDD?

What is arteriole diameter, The axons of all the baroreceptors in the body ...

The axons of all the baroreceptors in the body were destroyed at 2 AM.  All else is normal.  Which of the following statements is true for the system at 2:10 AM when compared to th

How to evaluate both the magnitude, According to the Nernst equation, the e...

According to the Nernst equation, the equilibrium potential for any ion (Eion) distributed across a membrane is dependent on the internal (Ionin) and external (Ionout) concentratio

Which part of the teeth is it important to remove plaque, From which part o...

From which part of the teeth is it particularly important to remove plaque. It is most significant to remove plaque from among the teeth and from the region where the gum cover

What is suprasternal views in echocardiography, Q. What is Suprasternal Vie...

Q. What is Suprasternal Views in echocardiography? To complete the echocardiography in the patients with CHD these views are essential. For optimal windows patient should lie

How thirst and satiety influence water intake, How Thirst and satiety influ...

How Thirst and satiety influence water intake? Thirst and satiety influence water intake, apparently in response to changes sensed by the mouth, hypothalamus and nerves. When t

DNA copying, why DNA copying is essential

why DNA copying is essential

What is the life cycle type of bryophytes, Q. What is the life cycle type o...

Q. What is the life cycle type of bryophytes? As in all plants the life cycle of bryophytes is diplobiontic (alternation of generations) and in bryophytes the lasting form is t

Classification of instrument sterilisation, The classification was given by...

The classification was given by Spaulding and is based on the contact with different tissue types to determine whether sterilization or disinfection is needed. 1. Critical item

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