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!
Crustose Lichen Stage - Xerarch
On bare rocks, conditions are inhospitable for life, as there is extreme deficiency of water and nutrients, great exposure to sun, and extremes of temperature. Crustose lichens alone are usually able to grow in such situations. Some examples of these pioneering species are, Rhizocarpon, Rhinodina, Lecidea and Lecanora. These plants flourish during periods of wet weather and remain in a state of desiccation for very long periods during drought. During the wet weather they rapidly absorb moisture by their sponge-like action. Mineral nutrients are obtained by the secretion of carbon dioxide which, with water forms a weak acid that slowly eats into the rock into which the rhizoids sometimes penetrate for a distance of several millimetres.
Nitrogen is brought by rain or by wind-blown dust. Thus all the life requirements of this simple, crust-like species is met with. Thus, lichens help corrode and decompose the rock, supplementing the other forces of weathering. And by mixing the rock particles with their own remains, make conditions favourable for - growth of other organisms. Thus, a thin layer of soil is formed. The rapidity with which a small amount of soil is formed is controlled largely by the nature of the rock and by the climate. On quartzite or basalt rocks in a dry climate, the crustose-lichen stage might persist for hundreds of years. But on limestone or sandstone in a moist climate, sufficient changes permit the invasion of foliose lichens, and all this may occur within a life time.
factors affecting nitrogen balance
Pollination Pollination refers to the transfer of pollen from dehiscing anthers to the pistil. Unlike animals, plants cannot move to their mates for sexual reproduction. Henc
Q. What are the major purposes of the organic molecules for living beings? Ans. Organic molecules, like, lipids, carbohydrates and proteins perform several functions for
CONCLUSION OF PHYLUM ANNELIDA
Define Polyacrylamide gel electrophoresis (PAGE)? Acrylamide gel has the advantage over starch in that it is easier to prepare and is more inert, the pore size can be varied in
Define the Properties of Fibre? The structural make up of fibre influences its properties which in turn affects the physiologic and metabolic roles. This is well-depicted in th
Photosynthetic function Structural organisation of the leaf is suitable to perform the process of photosynthesis. Hence leaf is called as a food factory. The leaf has a l
Explain Adverse effects of Indinavir In addition to adverse effects similar to those of other protease inhibitors, indinavir causes elevation of indirect bilirubin, indinavir
what are the two benefits of fever with explaination??
Cancer ; Cell division , like all other biological processes, is under genetic control. Certain genes must regulate the processes of cell growth and division in respons
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