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

List the reactions that need to be circumvented, List the reactions that ne...

List the reactions that need to be circumvented by the special reactions in gluconeogenesis. The reactions that are circumvented  include: Between pyruvate and phosphoenolpy

Embryology in relation to taxonomy, Q. Embryology in relation to taxonomy? ...

Q. Embryology in relation to taxonomy? Embryological information has been used for taxonomic purposes at various levels of classification. You know of a very basic division of

Rapport - building, Rapport-Building Here the Counsellor tries to esta...

Rapport-Building Here the Counsellor tries to establish a rapport and gain the client's trust. Let us see how we make friend? When we meet someone we take time to react, we ob

Starch, S T ARC H - Polymer of a-D-glucose. Starch is glucosan...

S T ARC H - Polymer of a-D-glucose. Starch is glucosan homopolysaccharide which is the major reserve food of plants. Starch is formed as an end product of photosynt

Extravascular compression, Most of the coronary blood flow to the left vent...

Most of the coronary blood flow to the left ventricular myocardium occurs during diastole. Thus the contracting heart obstructs its own blood supply. The systolic compressive force

Explain entecavir, Explain Entecavir  Entecavir  (Baraclude) taken ora...

Explain Entecavir  Entecavir  (Baraclude) taken orally once a day as monotherapy appears to be superior to lamivudine for patients with chronic HBV infection, but susceptibili

To study the structure of a seed, To study the structure of a seed Soak...

To study the structure of a seed Soak seeds of bean, pea, pumpkin, sunflower, corn and other large forms. Take away the seed- coats and carefully cut the seeds open. Discover t

Why does not gene therapy cure cystic fibrosis, Why doesn't gene therapy cu...

Why doesn't gene therapy cure cystic fibrosis? Although a normal gene is introduced into a patient's surface cells in the lung, these cells are not the ones that require produc

Which is not produced by the hypothalamus, Which of the following is NOT pr...

Which of the following is NOT produced by the hypothalamus? A) releasing hormones B) inhibiting hormones C) antidiuretic hormone D) oxytocin E) thyroid-stimulating h

What microbiology lab technician left the safranin out, If a microbiology l...

If a microbiology lab technician left the safranin out of the Gram stain procedure, what would be the result?

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