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

Mycoplasmosis-contagious bovine pleuropneumonia (cbpp), Contagious bovine p...

Contagious bovine pleuropneumonia (CBPP) This is a highly fatal disease of cattle and of major economic importance in certain tropical countries. It also affects buffaloes, bi

Explain the spectrophotometer or colorimeter, Explain the Spectrophotometer...

Explain the Spectrophotometer or Colorimete? These can be used to measure the microbial growth or can be used in various microbial and biochemical assays. Figure illustrates t

Reproduction, when pollen tube enters the embryo-sac,it has;

when pollen tube enters the embryo-sac,it has;

Describe the parathyroid hormone, A new drug named ANTAG-CaSR has been deve...

A new drug named ANTAG-CaSR has been developed that is an antagonist at calcium-binding sites of CaSRs (Calcium-Sensing Receptors) in the plasma membranes of parathyroid gland cell

Show the impressions at first - Transitional Restorations, Q. Show the Impr...

Q. Show the Impressions at first - Transitional Restorations? The dental technique will have modified the abutment to the desired shape and will now be able to fabricate the tr

What are the typical fauna of the taigas, What are the typical vegetation a...

What are the typical vegetation and the typical fauna of the taigas? Taiga, or the boreal forest, is characterized by coniferous trees, pine forests. There are also mosses, lic

What is continuous full thickness incision, Q. What is continuous full thic...

Q. What is continuous full thickness incision? 2. Continuous full - thickness incisions are indicated for a variety of situations outlined below. This type of incision may be u

Explain the swab method, Explain the Swab Method? Swab method is the ol...

Explain the Swab Method? Swab method is the oldest and widely used method in food and dairy industry and was developed by W.A. Manheimer and T. Ybanez in 1917. A sterile cotton

Chloroplast, Chloroplasts is the disk-like organelles with the double memb...

Chloroplasts is the disk-like organelles with the double membrane found in eukaryotic plant cells; contain thylakoids and are the site of the photosynthesis. ATP is produced durin

Are plant growth is depend on the plant harmones, Are the growth and develo...

Are the growth and development of plants only influenced by plant hormones? Chemical and Physical environmental factors, like position and intensity of light in relation to the

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