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

+illustrate sturdy evolutionary hypothesis, Q. Why is it a sturdy evolution...

Q. Why is it a sturdy evolutionary hypothesis that although viruses are the structurally simplest beings they were not the first living beings? The fact that viruses are obliga

Explain indications for surgery of total anomalous, Explain Indications for...

Explain Indications for Surgery of Total Anomalous pulmonary Venous Connection ? Once TAPVC is diagnosed in a neonate with symptoms, operation should be undertaken immediately.

Advantage & disadvantage of using fungi as source of protein, Define Advant...

Define Advantage & disadvantage of using fungi as source of protein? Advantages 1. Easy to harvest from culture medium. 2. Texture of the fungi improves the functional

Describe the various steps involved in glycolysis, Question 1 Give a detai...

Question 1 Give a detailed account on "high energy compounds" Question 2 Describe the various steps involved in Glycolysis Question 3 Give a detailed account on Oxidativ

What is a community, What is a community? What is the difference between th...

What is a community? What is the difference between the concepts of community and population? A community is a set of populations of living beings that live in the similar regi

Genetics of nitrogen-fixation, Genetics of Nitrogen-fixation The genet...

Genetics of Nitrogen-fixation The genetics of nitrogen-fixation is known in detail in Klebsiella pneumoniae. There are twenty genes required in organising the complete N 2 -fi

Drawbacks of lamellar model, Drawbacks of Lamellar model This model ...

Drawbacks of Lamellar model This model does not explain the elasticity of PM. Although this model says that PM is elastic but it also states that head of lipid molecules is

What are the typical fauna of the taigas, What are the typical vegetation a...

What are the typical vegetation and the typical fauna of the taigas? Taiga, or the boreal forest, is characterized by coniferous trees, pine forests. There are also mosses, lic

Define protein requirement at different stages of life cycle, Define Protei...

Define Protein Requirement at Different Stages of Life Cycle? Methods of Estimating and Assessing Protein Requirements at Different Stages of Life Cycle In this section, we

Define role of zinc in controlling gene expression, Define role of Zinc in ...

Define role of Zinc in controlling Gene Expression? Zinc atoms have specific structural roles in enzyme molecules, as well as, in many other proteins and in bio membranes. Thes

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