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.
The non-oxidative phase generates ribose precursors The non-oxidative phase of the pathway, including the following reactions, converts pentose-5-phosphate to other sugars.
Occurrence of Vitamin D Cholecalciferol is synthesized in the skin by the action of ultraviolet light on 7-dehydrocholesterol which is widely distributed in animal fat. Vitami
what is the life cycle of a protozoa
How does aldosterone act and where is it produced? Aldosterone is a hormone that acts upon the nephron tubules stimulating the resorption of sodium. Thus it contributes to the
How do taenias obtain food and make gas exchange? Tapeworms have hooks and sucking structures on their heads (scolex) that fixate the parasite in the gut wall; these structures
difference between RBC and WBC for homework
Why doesn't gene therapy cure cystic fibrosis? Although a normal gene is introduced into a patient's surface cells in the lung, these cells are not the ones that require produc
State the Effects of alcohol and smoking for diabetics patient A major concern with alcohol consumption is the potential danger of hypoglycaemia (low blood sugar), especially w
Elaborate Extracorporial in detail. Outside of the body. An example is extracorporial digestion found in some animals where digestive enzymes are regurgitated into food. Once i
Signify the term - Analogy, Analogous? Refers to structures that do not have the same evolutionary origin but have the same functions. The wings of a bat and insect are analogo
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