Origin and Evolution of Life
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Life is a unique and complex phenomenon that distinguishes the living organisms from non-living things or inanimate things. The origin of life in the universe is one of the most complicated problems for the biologists. The problem of creation resolves itself into two aspects: the origin of the forms of life and origin of life itself. Different biologists have proposed different theories concerning the origin of life. The major theories accounting for the origin of life are:- Life was created by a supernatural power at a particular time (Special Creation Theory
- Life arose from non-living matter on numerous occasions by a process of spontaneous generation (Theory of Spontaneous Generation)
- Life has no origin (Theory of Eternity of Present Condition)
- Life arrived on this planet from elsewhere (Cosmozoan Theory)
- Life arose according to chemical and physical laws (Biochemical Evolution)
Alexander Oparin-Theory of the origin of life
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Born : March 2, 1894Citizenship : Soviet Union
Died : 21-April, 1980
Nationality : Russian
Institutions : Moscow State University USSR Academy of Sciences
Known for : Contributions to the theory of the origin of life coacervates
Fields : Biochemistry
Notable awards : Hero of Socialist Labour (1969)
Kalinga Prize (1976)
Lenin Prize (1974)
Lomonosov Gold Medal (1979)
Biochemical Theory of Origin of Life
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- Formation of Simple Molecules
- Formation of Simple Organic Compounds
- Formation of Complex Organic Compounds
- Formation of Coacervates
- Formation of Primitive Life
- Origin of Heterotrophs
- Modification of Heterotrophs into Autotrophs
English natural philosopher-Robert Hooke
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| Robert Hooke |
Robert Hooke was an architect, Natural philosopher and polymath. His adult life comprised three distinct periods: as a scientific inquirer lacking money; achieving great wealth and standing .
Born: 28-July, 1635, (UK)United Kingdom
Died: 3-March, 1703, (UK)London,
Nationality: English
Books: Micrographia, more
Education: Oxford, Wadham College, Christ Church, Westminster School, Oxford, University of Oxford
Question Bank of Microscope
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Question Bank of Microscope
1. What is Microscope?
Ans: A microscope is an instrument used to magnify small objects that cannot be seen by naked eye.
2. How many times does a compound microscope magnify?
Ans : Magnifying power of a compound is equal to the magnifying power of the objective lens into the magnifying power of eyepiece. It varies from 100 times to 600 times or more.
3. Name the optical parts of a compound microscope.
Ans: Eye piece, objective lens and plano-concave mirror.
4. How is object magnified in compound microscope?
Ans: The power of eye piece and objective lens magnify the object.
5. Why observed the cells for the first time under the microscope?
Ans: Robert Hooke.
Handling of Compound Microscope
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Handling of Compound Microscope
1. Place the microscope on the table by holding the arm at the back with one hand and base with other hand
2. Fix the lower power objective and adjust the mirror so that light may pass through the objective. When you see a bright round space then you should be sure that light is passing properly through the stage to the objective.
3. Gently place a slide with the specimen over the stage. Use clips to hold the slide firmly.
4. Look through the eye-piece and adjust with the help of course adjustment until the object comes in view.
5. Now focus an object fine and sharp with the help of fine adjustment.
Magnification of Object
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A microscope magnifies an object in two stages. The lens system magnifies the object the 5 to 100 times depending on the power of the objective lens. The ocular lens magnifies an object 5 to 15 times. The individual magnification poser of the ocular or objective is written on the outside of its barrel. To calculate the total magnification the image with each objective, use the following equation:
Handling of Compound Microscope
Optical parts of a Compound Microscope
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Magnification of Object
Study of Microscopes
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A compound microscope is a delicate optical instrument consisting of two-lens system (eye piece and objective lens) that magnifies the minute transparent or translucent objects manifold in two steps and enables us to study their minute details. This two- fold magnification is the principle behind the working of the compound microscope. The compound monocular microscope consists of many parts, which are assembled to either mechanical parts or optical parts.Optical parts of a Compound Microscope
Mountain Technique
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Mounting is necessary to properly position an object for clear view. It is the last step in the process of slide preparation. For mounting, put a drop of suitable mounting medium such as water or glycerine or canada balsam on the center of a clean glass slide. Place the material on the mounting material with the help of a fine brush or forceps and finally place a clean cover slip on it. To place the cover slip properly, hold the cover slip with the forefinger and the thumb of the left hand and support it by a needle hold in the right hand. Lower down the cover slip slowly and touch one edge of the cover slip obliquely on one side of the mounting liquid. Holding the other edge of the cover slip with a needle point lower it down slowly to avoid air bubbles till it completely touches the slide. Suck the excess fluid outside the cover slip with the blotting paper.Technique of free-hand section cutting
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The first step of slide preparation is section cutting. Keep all the requirements needed for section cutting such as watch glass, sharp razor or safety blade, slide, brush, needles, water and materials in front of you. Hold the material vertically in between the thumb and fore fingure of the left hand in such a way that the material lies at the level of fore finger and the thumb below it. hold the razor or blade by the right hand, now, make a horizontal cut to material with a single stroke. Repeat the process several times by moving the blade rapidly so as to get a number of sections. Keep all the sections collected on the blade on water Preparation of different types of mount
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Technique of free-hand section cutting
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Laboratory Techniques
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1. Fixing agents and preservatives
2. Section cutting
3. Staining
4. Dehydration
5. Mounting
Section Cutting
When an internal tissue of anatomical structures of a particular organ is studied, a thin section of the concerned part is taken by freehand. The sections are cut in various planes:
1. Transverse section (T.S.)
2. Vertical section (V.S.)
General Instructions to the Students
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Preparation of Some Usefule Reagents- Laboratory Protocal
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While coming to the laboratory for the practical purpose, biological group students are required to bring certain necessary biological assets with them. The important assets are listed below:
1. Practical record book (biological drawing comments sheets, a cover file and a binding lace)
2. Manual of Practical Biology (A Text Book of Practical Biology -X1)
3. Apron
4. Pencils (HB)
5. Pencial sharpener, eraser and scale
6. Piece of cloth
7. Blotting paper
8. Disseeting set wiht following equipments:
a. Scissors: 2: one fine and pointed, other large bluntPreparation of Some Useful Reagents
b. Foreeps: 2:
c. Dissecting needles: 2 (spear headed)
d. Scalpels: 2: one small and one large
e. Fine camel-hair brush: 1
f. Blade: 1
g. Dropper: 1
h. Hand les: 1
i. Razor: 1
j. Magnifying lens (10X)
Students' Biological Practical Assets - Laboratory Protocal
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While coming to the laboratory for the practical purpose, biological group students are required to bring certain necessary biological assets with them. The important assets are listed below:
1. Practical record book (biological drawing comments sheets, a cover file and a binding lace)
2. Manual of Practical Biology (A Text Book of Practical Biology -X1)
3. Apron
4. Pencils (HB)
5. Pencial sharpener, eraser and scale
6. Piece of cloth
7. Blotting paper
8. Disseeting set wiht following equipments:
a. Scissors: 2: one fine and pointed, other large bluntPreparation of Some Useful Reagents
b. Foreeps: 2:
c. Dissecting needles: 2 (spear headed)
d. Scalpels: 2: one small and one large
e. Fine camel-hair brush: 1
f. Blade: 1
g. Dropper: 1
h. Hand les: 1
i. Razor: 1
j. Magnifying lens (10X)
Importance of Practical Work- Laboratory Protocal
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Safety Rules
1. Perform the laboratory experiments seriously.
2. Before conduction experiments, students must know about the experiment and precautions to be cared.
3. Do not play with any apparatus, microscope, razor, knife, etc.
4. Never talk loudly and run around the lab. Be calm in the laboratory.
5. For any damage or breakage, must inform to the lab incharge or instructor.
6. Use hand gloves for dissection of animals and wash your hands with soap and dettol after dissection.
7. In case of any accident, inform immediately to your instructor.
8. Handle the glassware carefully. Do not eat or drink in the laboratory.
Students' biological Practical Assets:
Laboratory Protocal
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