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

How does sexual reproduction take place in bacteria, Q. How does sexual rep...

Q. How does sexual reproduction take place in bacteria? How dissimilar are the modalities of bacterial sexual reproduction? Sexual reproduction occurs when bacteria incorporate

Explain the postoperative nutritional care, Explain the Postoperative Nutri...

Explain the Postoperative Nutritional Care? The therapeutic goal for the post-operative patient is rapid recovery to normal function and well being, minimum complications and e

What is the genotype for males and females, In humans, maleness or femalene...

In humans, maleness or femaleness is determined by a pair of sex chromosomes called X and Y.    (a) What is the genotype for males?    (b) What is the genot

Heart, which part of human body purify the blood

which part of human body purify the blood

Define some precautions for measurement of ph, Define some Precautions for ...

Define some Precautions for Measurement of pH? 1. Never touch the membrane of the glass electrode with anything else except soft tissue paper since it is fragile and is easily

Movements, Normal 0 false false false EN-IN X-NONE ...

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

Describe the basic function of platelets, Q. What is the function of platel...

Q. What is the function of platelets? What consequences does the clinical condition known as thrombocytopenia yield? Platelets, also known as thrombocytes are fragments of gian

Explain coelomates, Explain Coelomates? Recall that Acoelomates have so...

Explain Coelomates? Recall that Acoelomates have solid bodies, and Pseudocoelomates have body cavities that form between the endoderm and the mesoderm. In contrast, the body ca

Determine the importance of behavioural observations, Determine the importa...

Determine the importance of Behavioural observations Behavioural observations are often noteworthy to the extent that they involve alterations in the examiner's usual response

Define ovule, A vertical section of an ovule is shown below.  The correct p...

A vertical section of an ovule is shown below.  The correct ploidy levels of the four structures P, Q, R and S respectively are: a.  n, 2n, n, n b.  2n, n, n, n c.

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