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

Explain carboxymethyl cellulose, Carboxymethyl Cellulose (CMC) CMC is a...

Carboxymethyl Cellulose (CMC) CMC is a linear, long-chain, water-soluble, anionic modified polysaccharide. It is a derivative of cellulose formed by its reaction with alkali an

Advance techniques for construction of earthquake resistant , The conventio...

The conventional approach to design earthquake resistant building is based upon equipping the building with stiffness, strength and deformation due to elasticity which can afford a

Non insulin dependent diabetes mellitus, Q. Explain about Non Insulin Depen...

Q. Explain about Non Insulin Dependent Diabetes Mellitus? Overweight and obese adults are generally afflicted by this type of diabetes. The insulin produced by the pancreas is

I dont know, What are two specific organs that work together to preform a f...

What are two specific organs that work together to preform a function??

Developmental concepts unique to infants and young children, Developmental ...

Developmental Concepts Unique to Infants and Young Children The cognitive and social emotional development of infants and very young children has unique features. This age rang

How can coacervates be formed of phospholipids, How can coacervates be form...

How can coacervates be formed of phospholipids or polypeptides? Phospholipids are amphipathic molecules, i.e., they present a polar portion and a nonpolar portion. In contact w

What are the main divisions and representing species, What are the main div...

What are the main divisions and representing species of the gymnosperms? This group of plants can be divided into conifers (pine, sequoia, cypress), that have flowers known as

Explain cytoskeleton, What is cytoskeleton? What are its main constituents ...

What is cytoskeleton? What are its main constituents in animal cells? Ans) Cytoskeleton is the cytoplasmic structure that handles the cell, keeps its shape and fixates and moves

Excretory system - urinary bladder, URINARY BLADDER - Pear shaped sac l...

URINARY BLADDER - Pear shaped sac like. Situated in pelvic region of abdominal cavity. Ventrally placed. Lined by transitional epithelum. Detrusor muscle i.e. to expell out

Explain the urinary system in human body, Explain the Urinary System in hum...

Explain the Urinary System in human body? The urinary system removes the waste materials produced as a result of all the metabolic process required to sustain life. The process

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