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

Helobial type - endosperm, Helobial Type - Endosperm This type of endo...

Helobial Type - Endosperm This type of endosperm is intermediate between the nuclear and the cellular types. The division of the primary endosperm nucleus is followed by the f

Significance of the uterine glycogen- producing glands, Q. What is the sign...

Q. What is the significance of the uterine glycogen- producing glands? The uterine glands produce glycogen that able to degrade into glucose to nourish the embryo before the co

Phanerophytes - classes of life form, Phanerophytes - Classes of Life Form ...

Phanerophytes - Classes of Life Form The perennating buds in this case are present on erect, negatively geotropic shoots, much above the ground. These buds are naked or least

Define energy requirements for underweight, Define Energy requirements for ...

Define Energy requirements for Underweight? The total calorie intake should be 500 to 1000 Kcal in excess of the daily needs in order to result a gain in weight by half to one

Unconventional oilseed cakes/meal, Unconventional oilseed cakes/meal ...

Unconventional oilseed cakes/meal Deoiled sal (Shorea robusta) seed meal: It is a byproduct obtained after the extraction of oil from sal seeds. It is found to be high in NF

Groups of living beings that form the protist kingdom, Q. Which are the gro...

Q. Which are the groups of living beings that form the protist kingdom? The protist kingdom includes algae and protozoans. (Two groups of fungi with similar characteristics to

Assessment of magnesium status and dietary requirements, Define Assessment ...

Define Assessment of Magnesium Status and Dietary Requirements?  In order to estimate Mg requirements and establish relationship between magnesium intake and deficiency, it is

Growth curve, GROWTH CURVE - Sigmoid curve or stretched 'S' shap...

GROWTH CURVE - Sigmoid curve or stretched 'S' shaped curve is obtained showing - a - lag phase                              b - log phase c - in flaxion p

Cytology, who is the first person who saw the cell

who is the first person who saw the cell

Describe cardiac rewabilptation and its various effects, Describe cardiac r...

Describe cardiac rewabilptation and its various effects ? A survival benefit cannot be attributed solely to exercise training because many studies involved multifunctional inte

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