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

Intrisic and Extrinsic Limiting Factors, How do the ideas of energy and che...

How do the ideas of energy and chemical cycles, community structure, biodiversity and succession fit together to form the basis of the way the natural world works?

What is choanocytes, Which one of the following statements about all the fo...

Which one of the following statements about all the four of Spongilla, Leech, Dolphin and Penguin is correct? 1. Penguin is homiothermic while the remaining three are poikilothe

Define the vital force hypothesis, How did Pasteur's experiment answer the ...

How did Pasteur's experiment answer the objections raised by supporters of the "vital force" hypothesis? Pasteur's experiment allowed air from the out- side to mix with air fro

Cotyledon, Cotyledon is a leaf-like structure which is present in the seed...

Cotyledon is a leaf-like structure which is present in the seeds of the flowering plants; it appears during seed germination and sometimes is referred to as the seed leaf.

Donor selection and kidney preservation, DONO R SELECTION & KIDNEY PRESERV...

DONO R SELECTION & KIDNEY PRESERVATION - A kidney donor should be free of hypertension, diabetes & melignancy. Cardaveric kidney is obtained from brain death person. Kidney

Explain about the niacin - water soluble vitamin, Explain about the Niacin ...

Explain about the Niacin - Water Soluble Vitamin? Niacin is chemically synonymous with nicotinic acid although the term is also used for its amide (nicotinamide). Nicotinamide

How does the federal government regulate plant-incorporated, How does the f...

How does the federal government regulate plant-incorporated protectants and ensure their safe use in foods? EPA regulates the manufacture, sale and use of pesticides, containin

Implant system, In the early 1970's, Schroeder and his group designed a sin...

In the early 1970's, Schroeder and his group designed a single stage implant system known by the name of ITI Implant System. They demonstrated that one-stage implant can also resul

What is the predicted cell morphology, What are the predicted cell morpholo...

What are the predicted cell morphology, cell arrangement and gram stain results for each of the follow? 1. Bacillus megaterium 2. Staphylococcus aureus 3. Serratia marcesc

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