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

Determine the importance of educational history- assessment, Determine the ...

Determine the importance of Educational History- assessment  A complete school history includes information regarding a child's current grade placement, any grade repetitions o

Deficency diseases and metabolic disorders, Deficency Diseases and Metaboli...

Deficency Diseases and Metabolic Disorders Nutrients required for life sustenance are grouped into 6 basic classes, viz. water, carbohydrates, proteins, fats, minerals and vita

Define prevention in the prevalence of overweight or obesity, Define Preven...

Define Prevention in the prevalence of overweight or obesity? It is believed that the increase in prevalence of obesity worldwide is more due to the environment that has become

Echinoderms, simplest way to learn their classifiction

simplest way to learn their classifiction

Explain environmental resistance and the population growth, What is the rel...

What is the relationship among environmental resistance and the population growth according to the biotic potential curve and the real population growth curve? The difference

Which are the plant tissues that cover the stem and leaves, Which are the p...

Which are the plant tissues that cover the stem and the leaves? The stem may be enclosed by epidermis (having stomata, cuticle and photosynthetic cells) as in monocots or, alte

Explain about central nervous system, Central Nervous System (CNS) Cove...

Central Nervous System (CNS) Covering of the brain and spinal cord is called Meanings (membranes which cover and protect brain and spinal cord are called meanings) There is flu

Which term describes a very heart/pulse rate, In studies of human body, whi...

In studies of human body, which of the below terms is used to describe a very rapid heart rate or pulse rate? Is it: a) Tachycardia b) Bradycardia c) Cardiosis d) Myoc

Explain what is cyanosis and polycythemia, Explain what is Cyanosis and pol...

Explain what is Cyanosis and polycythemia? Cyanosis and Polycythemia: Central cyanosis involving the mucous membranes and trunk along with the lips and extremities in absence

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