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

In what order should personal protection be removed, Q. In what order shoul...

Q. In what order should Personal Protection be removed? Personal protection is removed in following order: Gloves Mask Glasses Wash hands

How do the products of meiosis i differ from of meiosis ii, How do the prod...

How do the products of meiosis I differ from those of meiosis II? In meiosis I, the offspring cells are haploid but every cell contains two copies of the chromosome because th

Marine biomes, The marine biomes consist of the earth's oceans and its asso...

The marine biomes consist of the earth's oceans and its associated areas like the shorelines, islands, reefs and estuaries. The marine waters contain about 3.5 percent salt, mostly

How is the brain involved in the immune system, How is the brain involved i...

How is the brain involved in the immune system? A. Immune cells that constitute body's biological defense against infections and toxins, have many things in common with nerve c

Which animals maintain constant body temperature?, Which of the below terms...

Which of the below terms is used to describe animals which maintain a constant body temperature by producing heat by metabolic oxidations (muscle contractions) and losing excess he

Clinical features of gout disease, Q. Clinical Features of gout disease? ...

Q. Clinical Features of gout disease? You may be enjoying good heath but may suddenly get a severe attack. You wake up in the middle of the night, and your big toe feels as if

Urine formation in crustaceans, Normal 0 false false false ...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Etiologic factor of congestive cardiac failure, Q. Etiologic factor of Cong...

Q. Etiologic factor of Congestive Cardiac Failure? Congestive heart failure develops over a period of time when the necrotic tissues are not replaced by functional connective c

What is the choice of a prophylactic agent, Choice of a prophylactic agent ...

Choice of a prophylactic agent An effective prophylactic regimen should be directed against the most likely infecting organisms, but need not eradicate every potential pathogen

What is periotest, What is Periotest Periotest: An electronic device ...

What is Periotest Periotest: An electronic device  originally developed by Schulte designed to measure the dampening effect or attenuation degree  characteristics of the peri

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