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

Define surface sampling, Define Surface Sampling Food contact surfaces ...

Define Surface Sampling Food contact surfaces (e.g. storage tank, packaging material, ripening room, utensils, equipments, refrigerators etc.) which directly or indirectly (wal

Effects of insulin on fat metabolism, Insulin promotes fat synthesis and st...

Insulin promotes fat synthesis and storage. Insulin transports fatty acids in the liver cells and then these are transported from the liver by blood to the adipose cells and are st

What is its function of cardia, Q. What is the route of the ingested food f...

Q. What is the route of the ingested food from swallowing until the duodenum? Until reaching the duodenum the food enters the mouth, passes the pharynx, passes the stomach and

Amphibia, an assignment of amphibians

an assignment of amphibians

Agro industrial-animal wastes, Animal wastes Large quantities of anima...

Animal wastes Large quantities of animal wastes are available in the country but generally they are low in nutrient content with poor feeding value to the animals. However, po

Define vitamin a, Define Vitamin A, Iron and Zinc required for elderly? ...

Define Vitamin A, Iron and Zinc required for elderly? Vitamin A, Iron and Zinc: The recommendation for iron is said to decrease in elderly women. Intake of vitamin E and zinc

Standard titration - estimation of vitamin c in chillies, Define Standard t...

Define Standard titration - estimation of vitamin c in Chillies? Pipette 5 ml of standard ascorbic acid solution into a 100 ml conical flask. Fill the burette with the dye solu

Explain about the fat metabolism - ageing, Explain about the Fat metabolism...

Explain about the Fat metabolism - Ageing? With increasing age, the blood cholesterol and blood triglyceride levels gradually increase. Certain factors like the kind and amoun

Properties and functions of synapses, Properties and Functions of Synapses ...

Properties and Functions of Synapses There is an interval between depolarisation of the presynaptic terminal and the earliest appearance of a postsynaptic response. This inter

Classification of proteins based on chemical properties, Classification of ...

Classification of proteins based on chemical properties? Depending on their chemical properties and optical activity, the amino acids in proteins are classified under the follo

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