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

Where does the water resorbed after glomerular filtration, Q. Where does mo...

Q. Where does most of the water resorbed after glomerular filtration go? What are the other substances resorbed by the nephron tubules? Only 0.5 to 1% of the glomerular filtrat

#title, IN WHAT ASPECT ARE CNIDARIANS SIMILAR TO PROTOZOANS

IN WHAT ASPECT ARE CNIDARIANS SIMILAR TO PROTOZOANS

What do you mean by ventricular arrhythmias, Q. What do you mean by Ventric...

Q. What do you mean by Ventricular Arrhythmias? Considerable disagreement exists regarding the significance of resting ventricular ectopic beats. In study comparing the coronar

Nature of stress - responses of plants to stress, Nature of Stress - Respon...

Nature of Stress - Responses of Plants to Stress As mentioned in the preceding section, stress can be considered as any deviation in environmental condition from optimal for t

Explain prevalence in coronaw artery disease, Explain Prevalence in coronaw...

Explain Prevalence in coronaw artery disease ? The first report to highlight the high prevalence of CAD among Indian expatriates came from an autopsy study done in Singapore. C

Hormones of pancreas, HORMONE S OF PANCREAS AND THEIR ROLE - (i) Glu...

HORMONE S OF PANCREAS AND THEIR ROLE - (i) Glucagon (Secreted by a-cells) It stimulates the liver to convert stored glycogen into glucose. Glucagon is controlled b

Physical signs of aortic regurgitation, Q. Physical Signs of aortic regurgi...

Q. Physical Signs of aortic regurgitation? Chronic severe aortic regurgitation is characterized by wide pulse pressure and multiple peripheral signs it produces. Sharp rapid up

Explain about the canning of food, Explain about the Canning of Food? Y...

Explain about the Canning of Food? You must have seen the markets flooded with canned products. Can you name a few of such products? Yes the canned juices, canned aerated drink

Implications of pharmacogenomic research, Problem 1: Describe the funct...

Problem 1: Describe the functions of: a. Glutathione transferases b. Sulfotransferases. -Describe the functions of: a. Glutathione transferases Describe the functions of

Assessment of aplastic anaemia, Assessment   The patient will present w...

Assessment   The patient will present with striking pallor, irritability and lethargy due to anaemia, bledding or bruising and petechiae due to thrombocytopenia, fever and infe

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