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

Describe the applications of vitamin B1, Describe the Applications of vitam...

Describe the Applications of vitamin b1 The steadily increasing consumption of white flours  (insufficiently ground and thus low in vitamin content) by large sections of the po

What is microtubules, What is Microtubules? Microtubules are the largest...

What is Microtubules? Microtubules are the largest intracellular fibers, with a diameter of about 25 nm (2.5 x 10-8 meters). They consist of hollow fibers composed of a protein

Isomerization of dihydroxyacetone phosphate, Isomerization of dihydroxyacet...

Isomerization of dihydroxyacetone phosphate Isomerization  of  dihydroxyacetone phosphate: Triosephosphate isomerase interconverts  dihydroxyacetone phosphate and  glyceralde

Describe occurs from a physiological standpoint, Describe the occurs from a...

Describe the occurs from a physiological standpoint to the respiratory system when smoke is inhaled and exhaled. You will need to use other sources aside from your textbook.

Define assessment of selenium status, Define Assessment of Selenium Status?...

Define Assessment of Selenium Status? Blood glutathione (GSH) peroxidase activity is directly related to blood selenium up to a level of 1.27 μmoles/L. Beyond this point, the a

Nervous system and sense organs, Nervous System and Sense Organs The n...

Nervous System and Sense Organs The non-chordates also perform a variety of activities such as feeding, digestion, locomotion etc. For this aim, they have corresponding organs

Explain the types of double beam systems, Explain the types of double beam ...

Explain the types of double beam systems? Following are types of double beam systems: a) Dual beam in space type b) Dual beam in time type In type (a) separate detecto

Musculoskeletal system, MUSCULOSKELETAL SYSTEM: Disease of  the skin  ...

MUSCULOSKELETAL SYSTEM: Disease of  the skin  and musculoskeletal  system occur commonly  in  early age group. There are  not many  statistics  to prove the exact frequency of

Abscission - effects of plant growth regulators, Abscission - Effects of Pl...

Abscission - Effects of Plant Growth Regulators Abscission of leaves and fruit is one of the more obvious characteristics of senescence. Leaves do not fall simply because they

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