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

Determine the chemical stage of photosynthesis, Which are the subproducts o...

Which are the subproducts of the photochemical stage that are essential for the chemical stage of photosynthesis? The chemical stage of photosynthesis depends on NADPH and ATP

Evolution of heart in higher animals, Evolution of heart in higher animals ...

Evolution of heart in higher animals The circulatory system in higher animals has undergone several changes during evolution. The heart has become totally muscular. Th

Amino acid, Amino acid is any of a class of 20 molecules which are combine...

Amino acid is any of a class of 20 molecules which are combined to form the proteins in living things. Consisting of the general formula NH2-CHR-COOH, where "R" is the side chain

Under which forms is the trypanosoma cruzi found, Q. Under which forms is t...

Q. Under which forms is the Trypanosoma cruzi found in its hosts? In the definitive hosts also as in triatomine bugs (intermediate hosts) the protozoan that causes Chagas' dise

Wetlands and estuaries, Wetlands and estuaries are transitional biomes. Lan...

Wetlands and estuaries are transitional biomes. Land that remains flooded either part of the year or permanently with fresh or salt water is known as wetland. The internationally a

Explain signal hypothesis, A classical secretory protein vary from a cytoso...

A classical secretory protein vary from a cytosolic protein by having a sequence about 13-35 amino acids long at its N-terminal end called as a signal peptide or signal sequence.

Magnitude of healthcare expenditure, Normal 0 false false f...

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

What is cellulose, What is cellulose? Cellulose is a long-chain polymer...

What is cellulose? Cellulose is a long-chain polymeric polysaccharide carbohydrate, of beta-glucose. It creates the primary structural component of green plants. The primary ce

Explain spoilage by yeasts, Q. Explain Spoilage by yeasts? Yeasts domin...

Q. Explain Spoilage by yeasts? Yeasts dominate in the spoilage of fruit products which contain high acid content due to their ability to tolerate high acid environment. Yeast

What is supraventricular arrhythmias, Q. What is Supraventricular Arrhythmi...

Q. What is Supraventricular Arrhythmias? Such arrhythmia tend to be reduced by the vagal withdrawal accompanying the onset of exercise.This and wandering pacemakers tend to rec

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