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

Estimate the molar mass of protein, Estimate the molar mass of protein? ...

Estimate the molar mass of protein? An aqueous solution of the protein bovine serum albumin, containing 2:00 *10 -2 g of protein per cubic centimeter, has an osmotic pressure

Light scattering, how does measurement of light scattering allows the growt...

how does measurement of light scattering allows the growth of cells to be monitored.

Vein grafts-longevity of conduits long term conduits, Vein Grafts :  ...

Vein Grafts :  At the end of ten years only 50 per cent of saphenous vein grafts are paten1 and 50 per cent of the rest may have significant atherosclerotic changes. In a

Describe the ideal primary stability, Less than ideal Primary Stability ...

Less than ideal Primary Stability Faulty osteotomy (a bigger osteotomy than required for the selected diameter of implant) can result when excessive force is used to disengage

Which part of heart serves as an actuating signal, Which of the following s...

Which of the following serves as an actuating signal, or as part of an actuating signal, in a negative feedback system? A. Action potentials in sympathetic neurons that release

Definition of biological diversity, Q. Definition of Biological diversity? ...

Q. Definition of Biological diversity? Biological diversity has no single standard definition. One definition holds that biological diversity is a measure of the relative diver

Cardinal manifestation of cardiovascular disorders, CARDINAL MANIFESTATION ...

CARDINAL MANIFESTATION OF CARDIOVASCULAR DISORDERS Cardiovascular symptoms that most often trouble patients are: 1. Chest Pain 2. Shortness of Breath 3. Palpitation

Explain back pain, Explain Back pain, arthritis and gout - Effect of Obesit...

Explain Back pain, arthritis and gout - Effect of Obesity? Abdominal obesity increases the risk of back pain because of the extra load on the spinal column. This, in turn, red

Anticoagulants, ANTICOAGULANTS (a ) Heparin (hepar = liver) . It is ...

ANTICOAGULANTS (a ) Heparin (hepar = liver) . It is synthesized by mast cells of connective tissue and liver cells. It is a heteropolysaccharide. It increases the effectivit

Imagine an animal that hast he system similar to abo blood, Imagine an anim...

Imagine an animal that has a system similar to ABO blood types in humans. The ABO part is the same. In addition, they have a second independent gene that creates a mimic A protein,

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