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

Difference between the concepts of food chain and food web, What is the dif...

What is the difference between the concepts of food chain and food web? The chain theory is a theoretical model to study the energy flux in ecosystems. In fact, in an ecosystem

Cytokinins - plant growth substances, Cytokinins - Plant Growth Substances ...

Cytokinins - Plant Growth Substances Folke Skoog observed that the cell division or differentiation is affected by AMP and other purines. A nucleic acid from yeast was also fo

Determine the term clade, Determine the term Clade? In cladistic taxono...

Determine the term Clade? In cladistic taxonomy, how groups of animals are related to each other. It includes the ancestral group and all of the other groups, or lineages, of a

Mechanism of enzyme action, Mechanism  of Enzyme Action  The action of...

Mechanism  of Enzyme Action  The action of enzymes is to lower  the activation energy  or threshold  of their substrates which. Therefore  become  activated and   react  with

What is p-k reaction, The response produced when an allergen is injected in...

The response produced when an allergen is injected into an individual, who is sensitive is known as P-K reaction.

Explain the use of benzoates acid, Q. Explain the use of Benzoates acid? ...

Q. Explain the use of Benzoates acid? Benzoic acid, sodium benzoate and the parahydroxy esters (parabens) are used as preservatives. Benzoic acid and its sodium salt, sodium be

What are the causes of endodontic pain, What are the causes of endodontic p...

What are the causes of endodontic pain? Lesions in retreatment cases called post endodontic diseases. Reasons of Endo retreatment; = reasons of failure: - Signs or symptoms of

Pathophysiology of leukemia, Pathophysiology   Leukocytes develop fiom ...

Pathophysiology   Leukocytes develop fiom stem cells located in the bone marrow. During  leukocyte maturation, cells become committed  to specific cell types and develop  throu

What is the function of the collagen fibers, What is the function of the co...

What is the function of the collagen fibers of the connective tissue? There are dissimilar collagen types. The major function of these proteins is to keep the shape and the str

Determine about the term - heterogeneous mixture, Determine about the term ...

Determine about the term - heterogeneous mixture The solid phase made up of soil and other source material for nutrients, is a heterogeneous mixture. Each nutrient source contr

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