54 Questions
What is the basic unit of structure and function in living organisms?
Cell
What is the branch of biology that deals with the study of structure and function of plant and animal cells?
Cytology
Who observed a thin slice of cork under the microscope and saw cell-like structures?
Robert Hooke
What is a thin slice of any part called?
Section
What is the purpose of the mirror in a microscope?
To reflect light through the specimen
What is the function of the condenser in a microscope?
To reflect light through the specimen
What is the purpose of the eyepiece in a microscope?
To magnify the image
What is the purpose of the objective lens in a microscope?
To magnify the image
What happens to cells when viewed under a microscope?
They become magnified
What was the significance of Robert Hooke's observation in 1665?
He observed cell-like structures in a thin slice of cork.
What is the purpose of the stage in a microscope?
To hold the specimen.
What is the function of the coarse and fine adjustors in a microscope?
To focus the image.
What is the term for the outer cover of a plant?
Periderm.
What is the purpose of the objective lens in a microscope?
To magnify the image.
What is the name of the scientist who constructed the simplest microscope in 1600?
Unknown.
What is the term for cutting a structure along its length?
Longitudinal section.
What is the purpose of the eyepiece lens in a microscope?
To magnify the image.
What is the significance of the invention of the microscope?
It allowed us to study cells in detail.
What is the main reason why cells can be observed easily under a microscope?
The microscope provides magnification
What is the purpose of the objective lens in a microscope?
To magnify the specimen
What type of section is obtained when cutting a structure along its length?
Longitudinal section
What is the name of the scientist who observed cell-like structures in a thin slice of cork?
Robert Hooke
What is the term for the study of the structure and function of plant and animal cells?
Cytology
What is the function of the coarse and fine adjustors in a microscope?
To adjust the image for better clarity
What is the purpose of the stage in a microscope?
To hold the specimen in place
What is the term for the outer cover of a plant?
Periderm
What is the significance of the invention of the microscope?
It allowed for the study of the structure and function of cells
What is the maximum magnification that can be achieved with a light microscope?
100X to 450X
Who formulated the cell theory?
Matthias Schleiden and Theodor Schwann
What is the size range of most cells?
10-100 microns
What is the shape of a nerve cell?
Elongated and branched
What is the largest cell in the animal kingdom?
Ostrich egg
What is the function of the eyepiece lens in a microscope?
To magnify the sample
What is the formula for magnification?
Observed size / Actual size
What is the shape of a red blood cell?
Discoidal
What is the smallest cell in the animal kingdom?
PPLO
What is the maximum magnification that can be achieved with a light microscope?
1500X
Who formulated the cell theory?
Matthias Schleiden and Theodor Schwann
What is the shape of a muscle cell?
Spindle
What is the size range of most cells?
10 to 100 microns
What is the formula for magnification?
Observed size / Actual size
What is the shape of a pigment cell of the skin?
Branched
What is the purpose of the objective lens in a microscope?
To magnify the object
What is the longest cell in the animal kingdom?
Nerve cell
What is the largest cell in the animal kingdom?
Ostrich egg
What is the maximum magnification that can be achieved with a light microscope?
1500X
What is the shape of a nerve cell?
Elongated and branched
What is the size range of most cells?
10-100 microns
What is the formula for magnification?
Observed size / Actual size
Who formulated the cell theory?
Matthias Schleiden and Theodor Schwann
What is the shape of a red blood cell?
Discoidal
What is the smallest cell in the animal kingdom?
PPLO (Pleuropneumonia like organism)
What is the longest cell in the animal kingdom?
Nerve cell
What type of lenses are available in a microscope?
Both objective and eyepiece lenses
Study Notes
The Fundamental Unit of Life
- The cell is the basic unit of structure and function in living organisms.
- Cytology is the branch of biology that deals with the study of structure and function of plant and animal cells.
Invention of Microscope
- The simplest microscope was constructed in 1600 and later used by Galileo and Anton van Leeuwenhoek.
- In 1665, Robert Hooke observed a thin slice of cork (dead cell) under the microscope and saw similar structures, which he called cells.
Microscope Sections
- A thin slice of any part is called a section.
- A longitudinal section is obtained by cutting along the length of the structure.
- A transverse section is obtained by cutting across the structure.
Working of a Microscope
- The object on a glass slide is kept on a stage bearing a central hole under an objective lens.
- Light is reflected through the specimen with the help of a mirror and condenser below the stage.
- The magnified image of the object can be seen through an eyepiece at the top of the microscope.
- Focusing is done by adjusting the coarse and fine adjustors fitted in the microscope.
- Eyepiece lenses of magnification 5X, 10X, 15X and objective lenses of high (40X, 100X) and low (10X) powers are available.
Observing Cells under Microscope
- Under the microscope, cells become magnified, making them easy to observe.
The Fundamental Unit of Life
- The cell is the basic unit of structure and function in living organisms.
Cytology
- Cytology is the branch of biology that deals with the study of structure and function of plant and animal cells.
Invention of Microscope
- The simplest microscope was constructed in 1600.
- Galileo and Anton van Leeuwenhoek used the microscope later.
- In 1665, Robert Hooke observed a thin slice of cork (dead cell) under the microscope and saw cell-like structures, which he called cells.
Observing Cells under the Microscope
- A thin slice of any part is called a section.
- A longitudinal section is obtained by cutting along the length, while a transverse section is obtained by cutting across the structure.
Working of a Microscope
- The object on a glass slide is kept on a stage bearing a central hole under an objective lens.
- Light is reflected through the specimen with the help of a mirror and condenser below the stage.
- The magnified image of the object is seen through an eyepiece at the top of the microscope.
- Focusing is done by adjusting coarse and fine adjustors fitted in the microscope.
- Eyepiece lenses of magnification 5X, 10X, 15X and objective lenses of high (40X, 100X) and low (10X) powers are available.
- Under the microscope, cells become magnified, making it easy to observe them.
The Fundamental Unit of Life
- The cell is the basic unit of structure and function in living organisms.
Cytology
- Cytology is the branch of biology that deals with the study of structure and function of plant and animal cells.
Invention of Microscope
- The simplest microscope was constructed in 1600.
- Galileo and Anton van Leeuwenhoek used the microscope later.
- In 1665, Robert Hooke observed a thin slice of cork (dead cell) under the microscope and saw cell-like structures, which he called cells.
Observing Cells under the Microscope
- A thin slice of any part is called a section.
- A longitudinal section is obtained by cutting along the length, while a transverse section is obtained by cutting across the structure.
Working of a Microscope
- The object on a glass slide is kept on a stage bearing a central hole under an objective lens.
- Light is reflected through the specimen with the help of a mirror and condenser below the stage.
- The magnified image of the object is seen through an eyepiece at the top of the microscope.
- Focusing is done by adjusting coarse and fine adjustors fitted in the microscope.
- Eyepiece lenses of magnification 5X, 10X, 15X and objective lenses of high (40X, 100X) and low (10X) powers are available.
- Under the microscope, cells become magnified, making it easy to observe them.
Microscope Lenses
- Various magnification powers of eye piece lenses: 5X, 10X, 15X
- Objective lenses with high powers: 40X, 100X and low powers: 10X
- Magnification formula: observed size / actual size
Magnification in Light Microscope
- Combination of objective lenses (10X, 40X) and eyepiece lenses (10X or more) results in magnification of 100X to 450X
- Best light microscope can magnify structures up to 1500 times their original size
Cell Theory
- Formulated by Matthias Schleiden (1838) and Theodor Schwann (1839)
- Cell Theory states:
- All living organisms are composed of cells and products of cells
- All cells arise from pre-existing cells
Cell Size and Shape
- Cell size ranges from 10 to 100 microns, with some cells visible to the naked eye
- Examples of cell sizes:
- Ostrich egg cell: largest animal cell
- PPLO (Pleuropneumonia like organism) cell: smallest cell, measuring 0.1 to 0.5 microns
- Longest animal cell: nerve cell, up to meters in length
- Cell shape depends on specific function, examples:
- Elongated and branched: nerve cell
- Discoidal/saucer: RBC
- Spindle: muscle cell
- Spherical: eggs
- Branched: pigment cell of the skin
- Slipper shaped: paramecium
- Cuboidal: germ cells of gonads
- Polygonal: liver cells
Microscope Lenses
- Various magnification powers of eye piece lenses: 5X, 10X, 15X
- Objective lenses with high powers: 40X, 100X and low powers: 10X
- Magnification formula: observed size / actual size
Magnification in Light Microscope
- Combination of objective lenses (10X, 40X) and eyepiece lenses (10X or more) results in magnification of 100X to 450X
- Best light microscope can magnify structures up to 1500 times their original size
Cell Theory
- Formulated by Matthias Schleiden (1838) and Theodor Schwann (1839)
- Cell Theory states:
- All living organisms are composed of cells and products of cells
- All cells arise from pre-existing cells
Cell Size and Shape
- Cell size ranges from 10 to 100 microns, with some cells visible to the naked eye
- Examples of cell sizes:
- Ostrich egg cell: largest animal cell
- PPLO (Pleuropneumonia like organism) cell: smallest cell, measuring 0.1 to 0.5 microns
- Longest animal cell: nerve cell, up to meters in length
- Cell shape depends on specific function, examples:
- Elongated and branched: nerve cell
- Discoidal/saucer: RBC
- Spindle: muscle cell
- Spherical: eggs
- Branched: pigment cell of the skin
- Slipper shaped: paramecium
- Cuboidal: germ cells of gonads
- Polygonal: liver cells
Microscope Lenses
- Various magnification powers of eye piece lenses: 5X, 10X, 15X
- Objective lenses with high powers: 40X, 100X and low powers: 10X
- Magnification formula: observed size / actual size
Magnification in Light Microscope
- Combination of objective lenses (10X, 40X) and eyepiece lenses (10X or more) results in magnification of 100X to 450X
- Best light microscope can magnify structures up to 1500 times their original size
Cell Theory
- Formulated by Matthias Schleiden (1838) and Theodor Schwann (1839)
- Cell Theory states:
- All living organisms are composed of cells and products of cells
- All cells arise from pre-existing cells
Cell Size and Shape
- Cell size ranges from 10 to 100 microns, with some cells visible to the naked eye
- Examples of cell sizes:
- Ostrich egg cell: largest animal cell
- PPLO (Pleuropneumonia like organism) cell: smallest cell, measuring 0.1 to 0.5 microns
- Longest animal cell: nerve cell, up to meters in length
- Cell shape depends on specific function, examples:
- Elongated and branched: nerve cell
- Discoidal/saucer: RBC
- Spindle: muscle cell
- Spherical: eggs
- Branched: pigment cell of the skin
- Slipper shaped: paramecium
- Cuboidal: germ cells of gonads
- Polygonal: liver cells
Learn about the fundamental unit of life, the structure and function of cells, and the history of microscopy in this introductory quiz.
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