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

What is oogenesis , What is Oogenesis ? The female sex cells, or eggs,...

What is Oogenesis ? The female sex cells, or eggs, are formed in the ovaries, the primary sex organs of the female. The precursor of the egg cells, or oogonia, are formed duri

Precautions for morphological characteristics of yeast cells, Precautions f...

Precautions for Morphological Characteristics of Yeast Cells? 1. Observe aseptic conditions. 2. Use only a small sample for staining. 3. No air bubbles should be in the s

Vitamin, fish liver oil is rich in which vitamin ???

fish liver oil is rich in which vitamin ???

The genetic code is degenerate, Because RNA is composed  of four parts of n...

Because RNA is composed  of four parts of nucleotides,  there are 43 =  64 possible codons,  which  is  64  possible  triplets  of  nucleotides   with  several  sequences. Furtherm

Pasteurellosis, Pasteurellosis Haemorrhagic septicaemia (HS) Synonym  ...

Pasteurellosis Haemorrhagic septicaemia (HS) Synonym    :    Gal Ghotu Causative organism B:2                              :    Pasteurella multocida Serotype Haemorrhage sept

Explain principle of fehling''s soxhlet method, Explain Principle of Fehlin...

Explain Principle of Fehling's Soxhlet method (Lane-Eynon method)? Reducing sugars are those which have free sugar groups and hence may be estimated directly by titrating the s

Phosphorylation of glucose, Phosphorylation of  glucose Glucose is con...

Phosphorylation of  glucose Glucose is converted to  glucose-6-phosphate since phosphorylated  intermediates do not readily penetrate cell membrane and  this commits glucose  t

Zoology, #question.characteristics of coelenterata?.

#question.characteristics of coelenterata?.

Explain limited mucosal contact diarrhoea, Q. Explain Limited mucosal conta...

Q. Explain Limited mucosal contact diarrhoea? Limited mucosal contact diarrhoea: It results from situations of inadequate mixing of chyme (semi-liquid mass of food passing thro

Prognosis, The course and ultimate prognosis of ARF is usually directly rel...

The course and ultimate prognosis of ARF is usually directly related to the severity of carditis. The course and prognosis also depends upon recurrence of rheumatic fever. In pre-p

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