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

Thyroid gland, THYROID GLAND - It develops from the endoderm of the ...

THYROID GLAND - It develops from the endoderm of the embryo. Th e thyroid gland is the largest endocrine gland located anterior to the thyroid cartilage of the larynx

Discuss the importance of septa in maxillary sinus, Discuss the importance ...

Discuss the importance of septa in maxillary sinus during a sinus lift or graft surgery. Septa, when present in the maxillary sinus will divide it into sections creating separa

Controlling of gaseous pollutants, The gaseous pollutants can be controlled...

The gaseous pollutants can be controlled through the techniques of combustion, absorption adsorption and cold trapping. (a)   Combustion: Though combustion is a major cause of i

Deciduous senescence - senescence, Deciduous Senescence - Senescence O...

Deciduous Senescence - Senescence Only the leaves senesce as in many trees. The senescence of leaves, or abscission occurs when at the base of a leaf a layer of cells is laid

3x samples collected in process validation, To get the idea on the process ...

To get the idea on the process capability that whether the intended process provides the consistent results or not(precision).

Phanerophytes - classes of life form, Phanerophytes - Classes of Life Form ...

Phanerophytes - Classes of Life Form The perennating buds in this case are present on erect, negatively geotropic shoots, much above the ground. These buds are naked or least

How does vitamin c act in the body, Q. How does vitamin C act in the body? ...

Q. How does vitamin C act in the body? What is the harm caused by insufficiency of vitamin C? Why was this deficiency also known as "sailors' disease"? Vitamin C, or ascorbic a

Explain law of the transmission of acquired characteristics, What is meant ...

What is meant by the law of use and disuse and by the law of the transmission of acquired characteristics? According to the law of use and disuse the characteristics of a body

Explain the types of foods used in space, Explain the types of foods used i...

Explain the types of foods used in Space? The various types of foods are enumerated herewith. Thennostabilized (T): Heat processed foods ("off-the-shelf' items) in aluminium

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