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

Excretion in earthworm, EXCRETIO N IN EARTHWORM - Main organs are neph...

EXCRETIO N IN EARTHWORM - Main organs are nephredia, pharyngeal, integumentary & septed nephredia. Main are septal nephredia situated on septa.Nephrostome present. Body

What do you mean by polyphagia, Q. What do you mean by Polyphagia? Incr...

Q. What do you mean by Polyphagia? Increased Hunger (Polyphagia): As patient is losing more sugar in the urine, he feels hungry very soon and tends to take more food. It is cal

Oxidation of succinate to fimarate, Oxidation of  succinate  to  fimarat...

Oxidation of  succinate  to  fimarate:  This reaction is catalyzed  by succinate dehydrogenase and FAD'  is needed as a cofactor. Malonate, structural of succinate, competitively

Movement of molecules into and out of a cell, how does a plasma membrane re...

how does a plasma membrane regulate movement of molecules into and out of a cell? is it polarity, integrity, permeability, or solubility? these are my choices

What are the part of the musculoskeletal system, Which are the organs that ...

Which are the organs that are part of the musculoskeletal system? The main organs and tissues that are part of the musculoskeletal system in humans are the cartilages, the bone

What is arteriole diameter, The axons of all the baroreceptors in the body ...

The axons of all the baroreceptors in the body were destroyed at 2 AM.  All else is normal.  Which of the following statements is true for the system at 2:10 AM when compared to th

Protozoa, which symbiotic protozoa present in digestive tract of termites?

which symbiotic protozoa present in digestive tract of termites?

Explain about stacking faults, Explain about Stacking faults Stacking ...

Explain about Stacking faults Stacking faults happen in a number of crystal structures, but the common example is in close-packed structures.  Face-centered cubic (fcc) struct

Clinical manifestations of bronchial asthma, Clinical Manifestations C...

Clinical Manifestations Can be chronic to acute, mild to severe. Acute attack often occur at night. During an acute attack, audible inspiratory and expiratory wheezing. Patie

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