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

Imaging techniques to test stress, Q. Imaging Techniques to test stress? ...

Q. Imaging Techniques to test stress? A screening exam with M-mode and limited Doppler should be performed at the start of the test, but a detailed echo examination is usually

Gram - negative bacteria, Organisms of the so-called HACEK group, (Haemophi...

Organisms of the so-called HACEK group, (Haemophilus, Actinobacillus actinomycetemcomitans, Cardiobacterium hominis, Eikenella species, Kingella kingae) which are part of the upper

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

Give the details of colour vision, Give the Details of Colour Vision Th...

Give the Details of Colour Vision The genes for colour sense are located on the X chromosome (recessive inheritance) and on chromosomes 3 and 7. Changes in the cone pigments as

What is the association between inflammation and fever, What is the associa...

What is the association between inflammation and fever? In the tissue region where inflammation happens bacterial toxins, cytokines, prostaglandins, interleukins and endothelin

How does the intensity of facilitated diffusion differ, How does the intens...

How does the intensity of facilitated diffusion vary in relation to the concentration of the moved substance? What is the limiting factor? Like simple diffusion facilitated dif

The principal nitrogenous excretory in humans, The principal nitrogenous ex...

The principal nitrogenous excretory compound in humans is synthesised: 1. in kidneys but eliminated mostly through liver 2. in kidneys as well as eliminated by kidneys 3.

What are extraembryonic membranes, Q. What are extraembryonic membranes? ...

Q. What are extraembryonic membranes? Extraembryonic membranes are membranous structures that appear in parallel with the embryo and play vital roles in the embryonic developme

What is peristomium. describe, What is peristomium. Describe? The segme...

What is peristomium. Describe? The segment behind the prostomium in annelids which contains the oral opening. This segment like the prostomium isn't a true segment and has no s

Eyes, Are dogs colour blind

Are dogs colour blind

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