Operculum - seed appendages, Biology

Assignment Help:

Operculum - Seed Appendages

The term operculum is applied to a plug-like structure formed in the micropylar portion of the seed by proliferation of cells at the tip of the inner integument or the nucellus. An operculum has been observed in seeds of many monocotyledonous families, such as the Commelinaceae, Musaceae, Lemnaceae and Zingiberaceae, and a few dicotyledonous families like Bignoniaceae and Nymphaeaceae.

In Lemna paucicostata, cells at the tip of the inner integument undergo a remarkable expansion after fertilization and form a dome-shaped, stopper- like operculum. Cells of the operculum are thick-walled and contain an orange-red substance. During germination of the embryo the operculum becomes detached from rest of the seed and facilitates emergence of the embryo.


Related Discussions:- Operculum - seed appendages

What is pulmonary embolism surgery indications, What is Pulmonary Embolism ...

What is Pulmonary Embolism Surgery Indications ? Indications for Surgery :  Acute pulmonary embolism with haemodynamic instability and hypoxaemia is nearly always fatal. Mor

Roles of glycogen metabolism, Glycogen is a huge polymer of glucose residue...

Glycogen is a huge polymer of glucose residues linked by α1-4 glycosidic bonds with branches every 10 residues or so by α1-6 glycosidic bonds.  Glycogen gives an significant energy

What are the parathyroids, Q. What are the parathyroids? Where are they loc...

Q. What are the parathyroids? Where are they located and what are the hormones secreted by these glands? The parathyroids are four small glands embedded two in each posterior f

Indications for surgery-pulmonary regurgitation, Indications for Surgery : ...

Indications for Surgery : Patients usually present with fatigue, dyspnoea and ventricular arrhythmias. If they have additional tricuspid regurgitation, pulmonary valve replacement

Explain lane eynon method procedure, Q. Explain Lane Eynon Method procedure...

Q. Explain Lane Eynon Method procedure? You will be carrying out the procedure in two steps using Lane Eynon Method. Step 1 It involves the standardization of copper s

What is the function of the testicles, Concerning reproduction what is the ...

Concerning reproduction what is the function of the testicles? The testicles are the male gonads, i.e., the organs where the production of gametes takes place. In human beings

What are the main techniques of genetic engineering, At the present level o...

At the present level of the biotechnology what are the main techniques of genetic engineering? The main methods of genetic engineering today are: the recombinant DNA technology

What is the production of the rna, Q. What is the production of the RNA cal...

Q. What is the production of the RNA called and what is the enzyme that catalyzes the procedure? The making of the RNA from information contained in the DNA is called transcrip

Which is the muscle tissue that moves the bones, Q. Which is the kind of mu...

Q. Which is the kind of muscle tissue that moves the bones? The bones are moved by the skeletal striated muscles these muscles are voluntary (controlled by volition).

Define vitamins and minerals requirement for cancer patients, Define Vitami...

Define Vitamins, Minerals and Phytochemicals requirement for cancer patients? Several vitamins particularly those of the B-group are essential to promote adequate metabolism of

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