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

Plankton - aquatic ecosystem, Plankton - Aquatic Ecosystem This group ...

Plankton - Aquatic Ecosystem This group includes both microscopic plants (phytoplankton) and animals (zooplankton) found in all aquatic ecosystems, except certain swift moving

Obelia, what are the economic importance of obelia?

what are the economic importance of obelia?

Mycotic diseases-sheep, Goat and sheep M. mycoides subsp. capri is the...

Goat and sheep M. mycoides subsp. capri is the cause of caprine pleuropneumonia, a serious malady of goats. The disease is prevalent in certain parts of this country. The mort

Express how that system accomplishes that necessity, Name a system that acc...

Name a system that accomplishes that necessity and explain how that system accomplishes that necessity.

Define the equilibrium potential for potassium ions, A complete motor neuro...

A complete motor neuron is removed from a frog and placed in a large volume of normal physiological saline.  The neuron is healthy; it has a stable resting voltage of -70 millivolt

Why the diluent is distilled water, A drug has a molec. weight of 200. How ...

A drug has a molec. weight of 200. How many grams would you use to make 100 ml of a solution that is isotonic (for man)? Assume that the diluent is distilled water and that the dru

What is excessive fat intake, What is Excessive Fat Intake? Although mi...

What is Excessive Fat Intake? Although minimum amount of fat is essential as calculated above but upper limit of fat should be drawn due to its link with an increased risk of d

Male reproductive system - seminal vesicles, SEMINAL VESICLES (UTERUS MESCU...

SEMINAL VESICLES (UTERUS MESCULANIS) - Seminal vesicles are elongated, convoluted, musculo glandular sac about 4 cm long ( 9 cm if straightened). Lined by pseudostratified e

Porifera, method of digestion in porifera

method of digestion in porifera

Blood flow - circulation, Normal 0 false false false EN...

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

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