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!
Transmission electron microscopy:
Around 1931-32 two German scientists. Knoll and Ruska. Invented transmission electron microscopy, and built the first transmission electron microscope (TEM) in 1938 .Hillier 1940 built a high resolution TEM. A strong beam of electrons, issued from tungsten filaments, passed through vacuum and focussed by electromagnets, producing a radiation wavelength of about 0.0005nm is used to illuminate objects in this electrons strike against a fluorescent screen, or directly fall onto a photographic film, producing an electron micrograph. A practical resolution of about 5 a and magnification of one to several hundred thousand have been achieved by this microscopy, combined with modern cytological techniques, this microscopy has enabled scientists to know of many finer details of cell structure down to the macromolecular level. This knowledge of ultra structure or sub microscopic structure of the cell has resulted into the establishment of Molexular Biology.
Knoll (1935) demonstrated the feasibility of scanning electron microscopy achieving a resolution of about 30 a for three dimensional study of surface topography of objects in considerable details. Von Adrienne (1938) built first scanning electron microscope (SEM) .It is smaller and simpler than TEM. Electrons used SEM does not pass through the object, but are simply scattered from the surface of the object.
Why do plants need to exchange gases with the environment? Plants require to do gas exchange because they create aerobic cellular respiration (like animals) and they need to ge
Fliylurn Basidiomycetes 1) The asexual reproduction is by means of basidiospores which are produced on a microscopic, club-shaped basidium. 2) The basidia are found in a fru
Explain Consultant dietitians Consultant dietitians work under contract with healthcare facilities or in their own private practice. They perform nutrition screenings for
How would you design, in principle, an experiment to test the hypothesis that a certain variety of lettuce seed needed daylight in order to germinate? You would need as large
Kidney Disease The target BP in chronic kidney disease is set at 130/80. This will retard the progression of renal function. The drugs recommended are the ACEI/ARBs. These c
What is Venous Hum in heart dieases? Characteristic: Continues sound with diastolic component often a higher pitched and louder than the systolic, best heard just above the c
How Vitamin E is directly related to selenium and PUFA? Selenium: An inter-relationship exists between vitamin E and selenium, as selenium functions as an integral par1
Define the Gel Electrophoresis? Gel electrophoresis is among the most powerful and yet conveniently used methods of macromolecular separation. The gels in common use, polyacryl
F o wl typhoid Fowl typhoid is caused by Salmonella Gallinarum , a Gram negative bacillus in the family enterobacteriaceae (serogroup D). Chickens are the natural hosts fo
In the F2 generation of hybridization for a given trait conditioned by a pair of alleles T and t, according to Mendel's first law what are the genotypes of each phenotypical form?
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: +1-415-670-9521
Phone: +1-415-670-9521
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd