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.
DIGESTION Digestive enzymes break down food particles into smaller units. You will see that the final breakdown products of protein digestion are single amino acids or small c
Which are the germ layers present in cnidarians? Which tissues of the animal do they originate? These beings there ectoderm and endoderm, two germ layers. Animals with only two
Q. What are the chemical substances that facilitate to compose the plasma membrane? The major constituents of the plasma membrane are phospholipids, proteins and carbohydrates.
B o v i ne viral diarrhoea Bovine viral diarrhoea (BVD) and mucosal disease (MD) are clinically dissimilar disease syndrome yet have a common viral etiology. The acute dise
differenciate between plasma and serum
biting mechanism in snakes
Cold Hardiness and Cold Acclimation In connection with cold response we would like to introduce two terms- cold hardiness and cold acclimation. Cold-hardiness ref
How do the repairing enzymes of the genetic system act? There are enzymes inside the cells that detect errors or alterations in DNA molecules and begin a repair of those errors
Autochory - Dispersal of Seeds This mechanism of self-dispersal is based on forceful expulsion of the seed from the fruit because of desiccation or turgidity of the cells of
Mechanism of Carcinogenesis In the preceding sub-section you learnt that carcinogenesis is a multistep process. Even though cancer may be caused by many agents chemical, p
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