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

Illustrate natural and phylogenetic classification, Q. Illustrate Natural a...

Q. Illustrate Natural and Phylogenetic Classification? Natural Classification Natural systems of classification reflect the situation as it might have existed in nature. T

Explain diseases of pericardium, Q. Explain Diseases of pericardium? Pe...

Q. Explain Diseases of pericardium? Pericardium is the sac covering the heart. Pericardium consists of two layers-the visceral pericardium (epicardium) and the parietal pericar

Gastrulation in amphibians, Gastrulation in Amphibians Amphibians com...

Gastrulation in Amphibians Amphibians comprise a large and moderately telolecithal egg. Cleavage is holoblastic and unequal generating a spherical blastula along with a reduc

Nucleus, NUCLEUS First described and christened by Robert brown 1831, a...

NUCLEUS First described and christened by Robert brown 1831, a nucleus is the largest and most important organelle of eukaryotic cells. It is membrane bound and generally locat

Define the glucose tolerance test, Q. Define the Glucose Tolerance Test? ...

Q. Define the Glucose Tolerance Test? In Glucose Tolerance Test (GTT) if the blood sample is to be taken in the morning, patient is advised to follow fasting instructions i.e.

Classification of drugs, CLASSIFICATION OF GENERAL DRUGS - 1 .       ...

CLASSIFICATION OF GENERAL DRUGS - 1 .       NATURAL DRUGS - Obtained from natural sources as minerals, animals, plants & microorganism. (i)       Minerals - It include

Sona, characters of phylum protozoa

characters of phylum protozoa

Explain the behaviour of pteridophytes, Q. Why are pteridophytes better ada...

Q. Why are pteridophytes better adapted to dry land than bryophytes? Were pteridophytes always less abundant than phanerogamic plants? Although pteridophytes and bryophyt

To which direction does the growth of one side of a stem, To which directio...

To which direction does the growth of one side of a stem, branch or root induce the structure to curve? While one side of a stem, branch or root grows more than the other side

Explain insect resistance, In 2003 nearly 70 million hectares globally were...

In 2003 nearly 70 million hectares globally were planted in genetically modi?ed crops. Of these, 73%  were plants such as soybean, corn and cotton, which were modi?ed to be he

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