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.
please give me the expansion for ''gradient hypothesis'' and the two types of gradient hypothesis in deelopment of animals in detailed manner
Chuck Darwin knew BLENDING THEORY, but he also knew that if it was true his NOT work because
Seed Coat Effects In some seeds dormancy is imposed by the presence of the seed coat; if this is removed, the seed germinates. Two possible types of mechanisms could be invol
Bomb calorimeter is used to determine the calorific value of solid and liquid fuels. Construction It consists of following parts 1. Stainless steel bomb:
How are secondary cell walls different from primary cell walls? Primary cell walls are assembled on the surface of the plasma membrane whereas the cell is growing. They can gro
Which are the types of neurons that participate in the spinal arch reflex? Where are their cell bodies situated? In the arch reflex first a sensory neuron located in the gangli
Most RNA molecules are single-stranded but an RNA molecule should hold regions that can form complementary base pairing where the RNA strand loops back on i
Define the functional properties of hydrocolloids The hydrocolloids not only have the functional properties but also have nutritional characteristics. Most polysaccharide gums
Define animals
Lens - Organogenesis of Eye and Limb There is much experimental proof that the lens formation in many species is dependent on the induction by the optic vesicle while it conta
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