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 do you mean by primary visual and auditory cortex, Q. What do you mean...

Q. What do you mean by Primary Visual and Auditory Cortex? Primary Visual Cortex - in posterior aspects of occipital lobes.  Receives visual information from optic nerve (crani

Animal physiology, what are the animals with respiratory organs?

what are the animals with respiratory organs?

Describe pulsation in cardian examination, Describe Pulsation in cardian ex...

Describe Pulsation in cardian examination? 1) Apex impulse; lowest and outermost point of definite cardiac pulsation. 2) Prominent pulsations in left parasternal region suggest

Causes of variation, CAUSE S OF VARIATION - Effect of environmental co...

CAUSE S OF VARIATION - Effect of environmental conditions Change in the gene pattern like - (a) Random distribution of homologous genes in meiosis (b) Crossing over

Week 5 Review Sheet I, How does true motility differ from brownian movement...

How does true motility differ from brownian movement? What morphological structre is responsible for bacteria motility? Why is the wet preparation discarded in disinfectant s

State the atp-sensitive potassium channel, Which of the following is true f...

Which of the following is true for the ATP-sensitive potassium channel? A. The channel is a spanning protein with a receptor site for ATP located on an extracellular region of

Define utilization of soy protein concentrate, Define Utilization of Soy Pr...

Define Utilization of Soy Protein Concentrate? Soy protein concentrates are used in food products for their nutritional characteristics or for their functional properties or fo

Explain severe acute respiratory syndrome, Severe Acute Respiratory Syndrom...

Severe Acute Respiratory Syndrome (SARS) After travelers' diarrhea, respiratory infection is the most common infectious disease affecting travelers. In the winter of 2003 a ne

Define both drosophila and bacteriophage, Alfred Sturtevant and Seymour Ben...

Alfred Sturtevant and Seymour Benzer's studies of recombination in both Drosophila and bacteriophage demonstrated which of the following? A. The gene is an indivisible unit and

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