Scanning electron microscopy, Biology

Assignment Help:

Scanning Electron Microscopy (SEM)

While 'TEM is useful to study the internal structul-c of thc ccll. SEM is an important technique if you wish to examine the surl'ace features of the specimen. Moreover, a specimen can be viewed at different angles. The resolving power of a SEM is lower than that of a TEM since a resolution of only about 3.0 nm can be attained hy SEM.

In a SEM, a low energy beam of electrons (primary electrons) strikes the surface of a specimen. This causes the emission of the secondar!, electrons from the specimen which are gathered by a photonlultiplier tube to form an image which is built up line by line as in the case of television. The image forlncci by SEM has a three-dimensional appearance. Unlike -in a TEM, the electrons in a SEM do not pass through the specimen.


Related Discussions:- Scanning electron microscopy

Buffalo-pox, B u f fa l o- p o x The disease i...

B u f fa l o- p o x The disease is caused by an orthopox virus, closely related to the vaccinia virus. It is not clear whether it should be considered

Lower invertebrates, adaptation of the phylum protozoa to its function

adaptation of the phylum protozoa to its function

Principles of animal nutrition, Food Chain The land mass, water bod...

Food Chain The land mass, water bodies and atmosphere are the three endowments of nature on which the living beings have to depend for their nourishment and sustenance. The

Sericulture, i want to know about sericulture for assignment degree level

i want to know about sericulture for assignment degree level

What is the plasma membrane of the cell, The plasma membrane is the outer m...

The plasma membrane is the outer membrane of the cell it delimits the cell itself and a cell interior with particular conditions for the cellular function. As it is selectively per

How to know what i already paid, I know the answer to the question but when...

I know the answer to the question but when I selected buy it said $80, now I want to know if it is $80 more or if you will subtract what I already paid to $80 and therefore will on

Skeletal system - skull, SKULL- Present in head region. It is suppor...

SKULL- Present in head region. It is supported on the top of vertebral column. It is made up of the hardest and denest bones in the human body. It consists of cranium

Which cannot react with dehydration reaction, Which of the following pairs ...

Which of the following pairs of functional groups CANNOT react with each other by a dehydration reaction? Select one: a. Carboxyl;Hydroxyl b. Carboxyl;Sulfhydryl c. Pho

Describe the electron transport system, a) Describe the electron transport ...

a) Describe the electron transport system. Where does it happen in a mitochondrion and what is the role of oxygen in it ? b) Explain the events that happen in the human heart du

Explain ebb or shock period - dietary management for burn, Explain the Ebb ...

Explain the Ebb or Shock Period - Dietary Management for Burns? During the initial bums after injury, the focus is on counteracting the stress induced neurohormonal and physiol

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

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!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd