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 cyanosis, What is Cyanosis ? Cyanosis: Cyanosis may be peripher...

What is Cyanosis ? Cyanosis: Cyanosis may be peripheral or central. Peripheral cyanosis almost exclusively involves lips and extremities. Normal neonates may have bluish extrem

Why do c4 plants have dimorphic chloroplasts, a) Why do C 4 plants have di...

a) Why do C 4 plants have dimorphic chloroplasts? Describe the different steps involved in C 4 photosynthetic carbon cycle in such plants.

What is root cap, What is root cap? Root cap is a protective structure ...

What is root cap? Root cap is a protective structure located in the tip of the growing root. It defends the meristematic tissue of the root forming a cap that surrounds the tip

How can you describe the homeostasis, Q. What is the homeostasis? What are ...

Q. What is the homeostasis? What are the sensors, effectors and controllers of homeostasis? Homeostasis comprises the processes by which the organism maintains extracellular an

State the medial pterygoid, Medial pterygoid Muscle bounds the pterygom...

Medial pterygoid Muscle bounds the pterygomandibular space medially which is entered when an inferior alveolar nerve block is administered. Infection of this space is dangerous

Human reproduction, Why is the human placenta referred to as haemochorial t...

Why is the human placenta referred to as haemochorial type? Name the hormone it secretes to facilitate parturition.

Donor selection and kidney preservation, DONO R SELECTION & KIDNEY PRESERV...

DONO R SELECTION & KIDNEY PRESERVATION - A kidney donor should be free of hypertension, diabetes & melignancy. Cardaveric kidney is obtained from brain death person. Kidney

Long-chain fatty acids, Fatty acid breakdown brings about the oxidation of ...

Fatty acid breakdown brings about the oxidation of long-chain fatty acids. The fatty acids are first transformed to their acyl CoA (coenzyme A) derivatives and then degraded by the

Public-private dichotomy in providing health services, Normal 0 ...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

According to their morphology how are bacteria classified, According to the...

According to their morphology how are bacteria classified? Bacteria present dissimilar morphological patterns. A bacterium can be classified into coccus, bacillus, vibrion or s

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