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

What is difference in electrical charge between two points, The difference ...

The difference in electrical charge between two points: Select one: is called the potential difference between those points. is called the diffusion potential between those p

Define reagents required for osazone test, Define Reagents Required for Osa...

Define Reagents Required for Osazone Test? - Solutions of glucose, galactose,fructose, lactose, maltose, sucrose. - Phenyl hydrazine mixture (2 parts of Phenylhydrazine hydr

Explain about cyanocobalamin, Explain about Cyanocobalamin Cyanocobala...

Explain about Cyanocobalamin Cyanocobalamin occurs as dark red crystals or as a crystalline hygroscopic powder of the same colour without odour and taste. Upon standing in the

Proteins requirement in dyslipidemia, Q. Proteins requirement in dyslipidem...

Q. Proteins requirement in dyslipidemia? Proteins: While the quantity of protein does not impose any significant impact on the serum lipoproteins, it is the quality of protein,

Name the term for cancer of the blood, Which of the below terms is also cal...

Which of the below terms is also called "cancer of the blood" - an uncontrolled, greatly accelerated production of white cells. Is it: a) Leukemia b) Polycythemia c) sick

Anatomical reason for the left bronchus to be more elevated, Q. What is the...

Q. What is the anatomical reason for the left bronchus to be more elevated than the right bronchus? Why in most cases of aspiration of foreign material by children is the object fo

Excretion, what is the composition of urine in fishes and reptiles ?

what is the composition of urine in fishes and reptiles ?

Define age as a determinants of nutrient requirements, Define Age as a dete...

Define Age as a determinants of nutrient requirements? Age: Requirements change with increasing age between birth and maturity. Nutrient requirements per unit body weight are h

Ribonucleases and deoxyribonucleases, Ribonucleases  and  deoxyribonuclea...

Ribonucleases  and  deoxyribonucleases These enzymes  are  responsible  for  the degradation of  dietary  nucleic acids. Ribonucleases  and  deoxyribonucleases secreted by  the

Conjugated proteins, CONJUG A TE D PROTEINS Besides being made of po...

CONJUG A TE D PROTEINS Besides being made of polypeptides, the conjugated proteins posses additional groups, metals or ions. Consists of protein and non-protein parts.

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