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

The signals for parturition originate from, The signals for parturition ori...

The signals for parturition originate from: 1. placenta only 2. placenta as well as fully developed foetus 3. oxytocin released from maternal pituitary 4. fully develop

Explain antimicrobial prophylaxis, Explain Antimicrobial Prophylaxis An...

Explain Antimicrobial Prophylaxis Antimicrobial prophylaxis can decrease the incidence of infection, particularly surgical site infection, after certain operations, but this be

Accidents resulting in death, Accidents Resulting in Death Accidents t...

Accidents Resulting in Death Accidents that cause death are dealt with in a different way. The law requires full compensation to the widow for complete life or until remarriag

Explain hepatitis c, Hepatitis C It provides sustained viral responses ...

Hepatitis C It provides sustained viral responses (SVRs) of 54% to 63%. When used as monotherapy, peginterferons once weekly are more effective than standard interferon 3 times

Disorders of pancreas, DISORDER S OF THE PANCREAS - (i ) Diabetes me...

DISORDER S OF THE PANCREAS - (i ) Diabetes mellitus (Hypoinsulinism) The insulin-dependent diabetes mellitus (IDDM) is caused by a failure of the Beta-cells to produc

Acute and chronic tonsilitis, Acute and Chronic Tonsilitis: Tonsilitis...

Acute and Chronic Tonsilitis: Tonsilitis refers  to the inflammation of  tonsils and lymphatic tissue that are located on each side of oropharynx. Acute infection of  tonsils

Family of proteins for cell adhesion, Why do we need a family of proteins f...

Why do we need a family of proteins for cell adhesion (what is the advantage of having a family of proteins?)

Composition of blood, Composition of blood: Take few ml. of fresh bl...

Composition of blood: Take few ml. of fresh blood in a test tube and before collecting the blood add a few drops of sodium oxalate or sodium citrate solution to prevent clot

What is the structure that maintains identical chromatids, What is the stru...

What is the structure that maintains identical chromatids bound? The structure that maintains identical chromatids bound is the centromere. Cell Nucleus Review - Image Diver

Explain the term kwashiorkor, Explain the term Kwashiorkor? The term Kw...

Explain the term Kwashiorkor? The term Kwashiorkor means the 'disease the first child gets when the second baby is born', that is, 'the sickness of the deposed child'. Thus, th

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