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

Egg envelopes, Egg Envelopes Like any other cell, all the eggs are co...

Egg Envelopes Like any other cell, all the eggs are covered by the cell membrane or plasmalemma It is with two layers of about 50 A? (unit membrane) separated by a gap of 60

List five advantages of dsme, Q. List five advantages of DSME? Followin...

Q. List five advantages of DSME? Following are the advantages of DSME. It enables the patient to 1. Accept the disease. 2. Gain knowledge about disease, its prevention

Differentiating causes of hypoxemia, Study and complete the following Mini ...

Study and complete the following Mini Clini: Differentiating Causes of Hypoxemia. Explain the pathophysiological mechanism of how the following disorders cause hypoxia: Pleu

What is the concept of universality of the genetic code, What is the concep...

What is the concept of universality of the genetic code? What are the exceptions to this universality? The genetic code is universal because the rules of protein codification b

Revenue recognition on long-term construction projects, Q. Revenue Recognit...

Q. Revenue Recognition on Long-term Construction Projects? Revenue Recognition on Long-term Construction Projects Company identifies revenue from a long-term construction proje

Right atrial pressure, RAP can be determined semiquantitatively by assessi...

RAP can be determined semiquantitatively by assessing collapse of the inferior vena cava during inspiration. The inferior vena cava is imaged subcostally and its diameter is exa

Tools used in taxonomy, Q. Tools used in Taxonomy? Before you plan for ...

Q. Tools used in Taxonomy? Before you plan for a field trip decide the tools and equipment required. Certain, equipments are necessary for plant collection. A collecting pick i

Anticoagulant therapy, Anticoagulant therapy To prevent blood clottin...

Anticoagulant therapy To prevent blood clotting on the valve, patients with prosthetic valves require life long anticoagulant therapy. The patient is put on oral antico

What are nutritional care related to neurological disorder, What are nutrit...

What are nutritional Care related to Neurological Disorder? Let us then move on to the nutritional care. The important goals of nutritional care are to: prevent further

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