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

Class bivalvia, Class Bivalvia Body in a bilohed mantle enclosed in a...

Class Bivalvia Body in a bilohed mantle enclosed in a two-valved shell; head reduced; mouth with labial palps but no radula; foot wedge-shaped; plate-like gills; sexes separa

Define regulation of amino acid levels in the blood, Define Regulation of a...

Define Regulation of amino acid levels in the blood? Regulation of amino acid levels in the blood: Vitamin D helps to prevent loss  of amino acids through the kidney and thus

What is growth monitoring of an infant, What is Growth Monitoring? In t...

What is Growth Monitoring? In third world countries, about half the children are short and underweight for their age. Inadequate nutrient intake is the main reason. Inadequate

Embryo and endosperm, What is the difference between embryo and endosperm?

What is the difference between embryo and endosperm?

What are some antibiotics used against fungi, Q. What are some antibiotics ...

Q. What are some antibiotics used against fungi? The systemic or topical azoles (like fluconazole, itraconazole and others), amphotericin B, the echinocandins (caspofungin, mic

Clinical presentation and investigation of hypertension, Any elevation in B...

Any elevation in BP is accompanied by increased risk of cardiovascular and cerebrovascular events and renal damage. The most distinctive pathological consequence

Describe what are non degradable pollutants, Question : (a) Briefly de...

Question : (a) Briefly describe what are non degradable pollutants? (b) What do you meant by ichthyosarcotoxic fishes and give two examples of ichthyosarcotoxic fish poiso

Remove the crown for reuse-endodontics principles, Remove the crown for reu...

Remove the crown for reuse - If the decision is made to remove the crown for reuse - The visibility is increased - Allowing for much easier removal of canal obstructions -

Explain the lectins or haemagglutinins, Explain the Lectins or Haemagglutin...

Explain the Lectins or Haemagglutinins? These are sugar binding proteins, having the ability to bind and agglutinate red blood cells (RBCs). You will find that they occur in mo

How protons, Give definitions of atomic number and atomic mass and how they...

Give definitions of atomic number and atomic mass and how they relate to protons, neutrons, and electrons in neutral atoms?

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