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 nutritional requirements in hot environments, Determine Nutrition...

Determine Nutritional Requirements in Hot Environments? Hot environments may be of two types: dry hot, as in the case of deserts or hot and humid in tropical rain forests and c

Classification of drugs, CLASSIFICATION OF GENERAL DRUGS - 1 .       ...

CLASSIFICATION OF GENERAL DRUGS - 1 .       NATURAL DRUGS - Obtained from natural sources as minerals, animals, plants & microorganism. (i)       Minerals - It include

Human skeleton, what are the main coponents of human skeleton?

what are the main coponents of human skeleton?

Classifications of carbohydrates based on number of carbon, Define the Clas...

Define the Classifications of carbohydrates based on number of carbon?   A chain-form monosaccharide that has a carbonyl group (C= O) on an end carbon forming an aldehy

Explain about steatorrhoea, Q. Explain about Steatorrhoea? Steatorrhoea...

Q. Explain about Steatorrhoea? Steatorrhoea is a symptom of the disorders of fat metabolism and malabsorption syndrome and can be defined as n condition of foul-smelling bulky

Volvox, what is the necessity of interdependence of a volvox organism in th...

what is the necessity of interdependence of a volvox organism in the colonial existence?

How far from the building should the fire hose be located, A fire hose ejec...

A fire hose ejects a stream of water at an angle of 38.8 ° above the horizontal. The water leaves the nozzle with a speed of 26.6 m/s. Assuming that the water behaves like a projec

differences between rna and dna , Ribo Nucleic Acid contains OH group at s...

Ribo Nucleic Acid contains OH group at second carbon where as Deoxyribo Nucleic Acid lacks OH group at Second carbon.....DNA is Double standed helix whereas RNA is single stranded

Endocrine glands that regulate sexual activity in males, Q. What are the en...

Q. What are the endocrine glands that regulate sexual activity in males? How does this regulation work and what are the involved hormones? In males the sexual activity is regul

What is the usual morphological feature of nematodes, Q. What is the usual ...

Q. What is the usual morphological feature of nematodes that differentiates them from platyhelminthes? Nematodes are also called as roundworms. As the name indicates they are n

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