Wet stigma - category of stigma, Biology

Assignment Help:

Wet Stigma - Category of Stigma

Petunia shows several randomly distributed 2-celled papillae on its surface. In a developing stigma, the epidermis is covered by a continuous, thin cuticle and the subepidermal cells are densely cytoplasmic, without any intercellular spaces. In a mature stigma, the cells of the subepidermal zone elongate to form a secretory zone with large schizogenous cavities filled with a lipoidal secretion. The secretory zone is delimited from the basal part of the stigma by a storage zone.

The cells of the stigma contain numerous amyloplasts and a large amount of lipid globules which gradually coalesce and migrate to the peripheral part of the cytoplasm and eventually out of the cell. The lipoidal exudate accumulates between the cell wall and the cuticle. In the secretory zone the exudate fills the large intercellular, schizogenous cavities. At the time of anthesis, the epidermis becomes disorganized, the cuticle is discarded in the form of flakes and the accumulated exudate spreads over the entire surface of stigma. A very thin layer of water is also trapped.


Related Discussions:- Wet stigma - category of stigma

Explain the penicillium - fungi, Explain the Penicillium - Fungi? Class...

Explain the Penicillium - Fungi? Classification Kingdom - Mycetae Division - Amastigomycota Class - Ascomycetes Subclass - Plectomycetidae Order - Eurotiales

Can you explain ventricular tachycardia, Q. Can you explain Ventricular Tac...

Q. Can you explain Ventricular Tachycardia? The term is usually reserved for at least four or more beats and modified by the term non sustained. Short runs of non-sustained VT

What about whale fins compared to fish fins, Q. Are the limbs modified into...

Q. Are the limbs modified into wings of bats and the wings of birds instance of evolutionary homology or analogy? What about whale fins compared to fish fins? Bird and Bat wing

Physiological adaptation of parasites for infectioness, physiological adapt...

physiological adaptation of parasites for infectiousness?

Care of psychoemotional aspects of patient in icu, Care of Psychoemotional ...

Care of Psychoemotional Aspects ICU area is an area which is cut off from outside world. Modem ICUs are built in such a way that the sensory deprivation is reduced. Ta

Placement of implant with improper axial angulation, Placement of implant w...

Placement of implant with improper axial angulation Surgical placement of the implant improperly can lead to a prosthetic rehabilitation that compromises esthetics and the dist

What is diatoms, What is Diatoms? Bacillariophyta are commonly known as ...

What is Diatoms? Bacillariophyta are commonly known as diatoms because of their unique structure. These unicellular photosynthetic organisms are composed of two overlapping glas

Write the meaning of insulin, Q. Write the meaning of insulin? Insulin ...

Q. Write the meaning of insulin? Insulin is a hormone. And like many hormones, insulin is a protein. Insulin is secreted by groups of cells within the pancreas called islet cel

Rule of distal transformation of blastema, Rule of Distal Transformation of...

Rule of Distal Transformation of Blastema An intriguing phenomenon characteristic of limb regeneration is, that just only the part of the limb removed distal to the level of a

What is the definition of polyphenols, What is the Definition of Polyphenol...

What is the Definition of Polyphenols? Polyphenols are the compounds that contain an-ON group attached to the benzene ring. The main classes are: flavonoids, phenolic acids and

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