Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
The Exine Layer
It consists of two layers, inner (nexine) which is continuous and an outer (sexine) the sculptured one. The outer layer has ornamentations comprising rod-like bacula showing terminal expansion which sometimes fuses to form a roof like tectum perforated by micropores. During pollen development, the tapetum releases a mixture called tryphine, consisting of carotenoid lipid droplets and fibrogranular proteins into the thecal cavity. These fibrogranular proteins are enclosed in membrane bound cisternae. In tectate pollen, the released substances of tapetum become incorporated on the surface of pollen grains where cisternae membrane ruptures and protein released through micropores enter the tectum and accumulate in the interspaces of bacula.
Pollenkitt is the pigmented lipid fraction left on the surface of the tectum. Unlike intine, the exine held proteins exhibit only one enzymatic activity. The hydration of pollen is described to be stimulatory in releasing the proteins held in the pollen wall layers. The calculated time taken by the exine held proteins of sporophytic origin to pass out is 30 seconds while the intine of gametophytic origin takes a few minutes. This time difference in the protein release has made it easy to collect both samples separately. In SSI systems therefore the rejection reaction is faster than in GSI system.
Q. What are the main limiting factors for the growth of a population? The factors that bound the growth of a population can be divided into abiotic factors and biotic factors.
Explain Serum lipoprotiens Serum lipoprotiens:- spherical or ellipsoidal particles containing proteins, cholesterol esters and triacylglycerols, encased within a mon
Prostaglandins Prostaglandins belong to a subclass of lipids known as the eicosanoids because of their structural similarities to the C-20 polyunsaturated fatty acids, t
Which one of the following structures between two adjacent cells is an effective transport pathway? 1. Plasmodesmata 2. Plastoquinones 3. Endoplasmic reticulum 4. Plasm
pisces kingdom
Amphibians - Regeneration in Vertebrates Newts and salamander show remarkable regenerative ability in larval as well as adult stages. In larval stages except for limbs and tai
what is cytoskeleton
Hormones
Explain Suturing - Endodontic Surgery a. Purpose of suturing: approximation of inside tissues and stabilize the flapped mucoperiosteum b. Major problem of suturing in oral t
Classification according to the modes of transmission 1. Direct zoonoses: The direct zoonoses are those zoonoses that are transmitted from an infected vertebrate host to a
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!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd