Light microscopy, Biology

Assignment Help:

Light microscopy:

Microscopy started with light microscopes using visible light to illuminate the objects, the most used and familiar microscope is called compound light microscope. Its simplest form it consists of two optical lenses, one at each of a hollow tube. The lens closer to the object is called objective and the one closer to the observer eyes is called eyepiece. The object, mounted upon a glass slide, which  is put upon a centrally perforated satge  under the objective, is illuminated by light , a mirror is fitted below the stage to focus light on  to the object, a third lens system ,called  condenser may be fitted between the mirror and the stage to concentrate the light. The limit of the resolving power of best compound light microscopes is about 0.2 achieving a magnification of about 2000 times the size of the objects. Thus these microscopes can resolve even most of the bacteria, but they cannot reveal   the internal details of bacterial cells.

Use of ground glasses as optical lenses to magnify objects was presumably realized several centuries ago. The first name on record is of Conrad Gesner who used magnifying lenses to observe certain foraminifera's. Next Zacharias Janssen (Dutch 1590) constructed, together with his father, Hans Janssen the first compound light microscope to study insects which  could magnify objects 10 to 30 times. Galileo constructed microscope with greater magnifying powers and studied the arrangement of facets in the compound eyes of insects. Marcello Malpighi (1628-1694)  microscopically studied animal and plant tissues in  thin slices of several organs, earning the  title of the father of microscopic anatomy,  Robert Hooke (English 1665)  designed a compound light microscope  either a magnifying power of about 42 times and studied amongst other  object thin slice  of cork  discovering cells. Antony van Leeuwenhoek  (Dutch 1676)  designed single lens microscopes with magnifications approaching   300 times and become the first to observe sperms, blood cells muscle fibres, lenses of eyes,  hydrae yeast cells and microscopic organisms in water like bacteria, protozoan's  rotifers tec. Earning the little of the father of microbiology so commonly used these days by students in schools and collages all over the world , was developed from Hooke  model by Wilson (1970).

Zigmondy (1900) designed an ultra microscope using ultraviolet rays in place of ordinary light and quartz lenses in place of ordinary glass lenses, achieving a resolving power of0.1 and magnification of about 4000 times.


Related Discussions:- Light microscopy

Excretion in cockroach, EXCRETIO N IN COCKROACH- Animal is uricotelic....

EXCRETIO N IN COCKROACH- Animal is uricotelic. Excretory organs are malphighian tubules. 60-150 in 6-8 groups. In each group 10-15. Yellow coloured, blind tube, open in gut

How to identify the monomer or molecular components, Please help with the f...

Please help with the following: For each of the four macromolecules carbs, lipids, proteins and nucleic acids, please identify the monomer or molecular components and name the b

Explain the characterstics of acute ar murmur, Explain the characterstics o...

Explain the characterstics of Acute AR Murmur ? Characteristic: Relatively low pitched, decrescendo diastolic murmur, which may end part way through diastole. These murmurs ar

Explain enfuvirtide, Explain Enfuvirtide Enfuvirtide is the first fusio...

Explain Enfuvirtide Enfuvirtide is the first fusion inhibitor approved by the FDA for treatment of HIV infection and is indicated for treatment-experienced patients with ongoin

Explain deformaties of the cliest wall should be noted, Explain Deformaties...

Explain Deformaties of the Cliest wall should be Noted a) Pectus carinatum (pigeon chest): may be associated with Marfan syndrome. b) Pectus excavatum: commonly seen in Marfan

What is mendelian genetics, What is Mendelian Genetics? Mendelian Gene...

What is Mendelian Genetics? Mendelian Genetics :  In 1868, an Austrian monk, Gregor Mendel, first published the basics of a study we now call Mendelian genetics. Mendel obser

What are four initial stages of the embryonic development, Q. What are the ...

Q. What are the four initial stages of the embryonic development? The four early stages of the embryonic development are the blastula stage, the morula stage, the gastrula stag

What are ions, What are ions? What are the two types of molecules into whic...

What are ions? What are the two types of molecules into which ions are classified? Ions are atoms or substances electrically charged by means of loss or gain of electrons.

Explain cyanotic heart disease breifly, Explain Cyanotic Heart Disease brei...

Explain Cyanotic Heart Disease breifly? Presence of cyanosis means deoxygenated blood reaching the systemic circulation bypassing the lungs i.e., right to left shunt. Uniform c

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