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

Explain the salient feature of genetic code, The one aspect which is not a ...

The one aspect which is not a salient feature of genetic code, is its being: 1. Degenerate 2. Ambiguous 3. Universal 4. Specific Ambiguous

Plant breeding, #questitypes of plant breeding on..

#questitypes of plant breeding on..

Why is cannibalism an inharmonious ecological interaction, Q. Why is cannib...

Q. Why is cannibalism an inharmonious intraspecific ecological interaction? In the cannibalism an individual eats other of the same species (occurs in some arachnids and insect

Define food sources of calcium, Define Food Sources of Calcium? Dairy p...

Define Food Sources of Calcium? Dairy products are of course the primary source of calcium followed by grains and pulses. Among the millets, ragi contains substantial amount of

Estimation of protein by miscellaneous parameters include, Estimation of pr...

Estimation of protein by Miscellaneous parameters include? Miscellaneous parameters include Plasma amino acid levels Microbiological methods Chemical scoring

Determine what the abnormal levels of afp signal, Determine what the abnorm...

Determine what the abnormal levels of AFP signal Abnormal levels of AFP may signal the following: Open neural tube Defect (ONTD) Down syndrome Other chromosoma1

Explain typical components of a closed circulatory system, What are the typ...

What are the typical components of a closed circulatory system? The typical components of the closed circulatory system are the blood vessels within which blood circulates (vei

Where in leaves the photosynthetic tissue often located, Where in the leave...

Where in the leaves is the photosynthetic tissue often located? The major photosynthetic tissue is the photosynthetic parenchyma (also called as chlorenchyma, do not confuse wi

Protozoa., show me the schamatic diagram of chrysomoeba?

show me the schamatic diagram of chrysomoeba?

Explain hyperthermophilic organisms, Some hyperthermophilic organisms that ...

Some hyperthermophilic organisms that grow in highly acidic (pH2) habitats belong to the two groups: 1. Eubacteria and archaea 2. Cyanobacteria and diatoms 3. Protists and

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