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

Explain about cold preservation - methods of food processing, Explain about...

Explain about Cold Preservation - methods of food processing? The metabolism of a living tissue is a function of the temperature of the environment. Low temperatures are used t

Classification, Tricks of learn a classification (molusca,arthopoda,prifera...

Tricks of learn a classification (molusca,arthopoda,prifera etc.)

Determine some food sources of chromium, Determine some Food Sources of chr...

Determine some Food Sources of chromium? Chromium occurs in trivalent form in foods. Good sources of chromium include whole grains, spices and condiments, meats especially orga

Access burs through the crown-endodontics principles, Access burs through t...

Access burs through the crown:    Carbide fissure burs : cut through metal ( amalgam alloy or cast metal ) or composite resin.    Porcelain fused to metal : -A round diam

Describe class diplopoda and chilopoda in detail, Describe Class Diplopoda ...

Describe Class Diplopoda and Chilopoda in detail? Members of the Subphylum Crustacea and the Subphylum Uniramia have one major characteristic in common. Both groups have biting

What is class asteroidea, What is Class Asteroidea ? Sea stars are prob...

What is Class Asteroidea ? Sea stars are probably one of the most recognizable of all Echinoderms. Often beautifully colored and symmetrical, they are predators that feed vorac

State about heller nitric acid test, State about Heller's Nitric Acid Test ...

State about Heller's Nitric Acid Test Take 1 ml concentrated (fuming) nitric acid in a test tube and add 2 ml of urine by means of a pipette by the side of the test tube and la

Determine the types of neuropsychology, Determine the types of neuropsychol...

Determine the types of neuropsychology The practise in neuropsychology is roughly divided into two approaches. Some practitioners use standard comprehensive neuropsychological

Explain genotypical and phenotypical forms, In the F2 generation of hybridi...

In the F2 generation of hybridization for a given trait conditioned by a pair of alleles T and t, according to Mendel's first law what are the genotypes of each phenotypical form?

Illustrate nernst equilibrium potential for potassium ions, Illustrate Nern...

Illustrate Nernst equilibrium potential for potassium ions A complete motor neuron is removed from a frog and placed in normal physiological saline at 1 AM.  The neuron is hea

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