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

Types of cell respiration, Q What are the kinds of cell respiration? Th...

Q What are the kinds of cell respiration? There are two types of cell respiration aerobic cell respiration a reaction with participation of molecular oxygen (O2) and anaerobic

What is counsellor, Q. What is Counsellor? Counsellor is someone who gi...

Q. What is Counsellor? Counsellor is someone who gives advice about the problem. A counselor's role is to help patients help themselves. In our context  a counsellor is  a comm

Structure of human spermatozoon, Structure of human spermatozoon: Na...

Structure of human spermatozoon: Nature: Human sperms are minute, microscopic and motile. Structure: Each sperm have an oval shaped head piece, a neck, a middle piece and

What are autotrophic beings? what are heterotrophic beings, What are autotr...

What are autotrophic beings? What are heterotrophic beings? The Autotrophic beings are those that can produce their own food that is that make organic material from inorganic c

Preprocedure care, BRONCHOSCOPY: Bronchoscopy is the passage of lighte...

BRONCHOSCOPY: Bronchoscopy is the passage of lighted bronchoscope into the bronchial tree. Bronchoscopy may be performed with  rigid steel of flexible fiberoptic instruments.

What do you understand by coelenteron, What do you understand by Coelentero...

What do you understand by Coelenteron? The name given to internal cavity of the cnidarians. This is an incomplete gut with just one opening, the mouth. Food to be digested and

Classification and features of echinodermata, Classification with its Justi...

Classification with its Justification Kingdom Animalia Animals, multi-cellular organisms with cells that lack a cell wall, many capable of movement or movement of some o

Describe transfer rna, Transfer RNA which is also known as tRNA is an adapt...

Transfer RNA which is also known as tRNA is an adaptor molecule composed of RNA, classically 73 to 93 nucleotides in length, which serves as the physical link between the nucleotid

What is the average number of minutes a cell, You have 200 cells and find 1...

You have 200 cells and find 120 in interphase, 57 in prophase, 8 in prometaphase, and 5 in metaphase, 8 in anaphase and 2 in telophase. (None in G0 phase). it takes 18 hours to com

Endocrine glands, Endocrine glands Endocrine glands have no ducts - ...

Endocrine glands Endocrine glands have no ducts - so these are also called as ductless glands Eg.Pituitary etc., These glands secrete chemical substances called HORMONES

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