KARMAVEER VIDYA PRABODHINI, SATARA. MADHYA VIBHAG POWERPOINT PRESENTATION 9 TH STD.-SCIENCE & TECHNOLOGY WITH SYLLABUS 2011-12 RAYAT SHIKSHAN SANSTHA,

KARMAVEER VIDYA PRABODHINI, SATARA.

MADHYA VIBHAG

POWERPOINT PRESENTATION

9TH STD.-SCIENCE & TECHNOLOGY WITH SYLLABUS 2011-12

RAYAT SHIKSHAN SANSTHA,SATARA

9TH 5. CELL: THE UNIT OF LIFE SCIENCE

STD. & TECH-PPT

9TH 5. CELL: THE UNIT OF LIFE SCIENCE STD. & TECH-PPT

UNIT :- CELL : 5. THE UNIT OF LIFESUB UNITS :-5.1 CELL AS A BASIC UNIT OF LIFE 5.2-STRUCTURAL ORGANIZATION

OF A CELL 5.3- CELL ORGANELLES 5.4- PROKARYOTIC & EUKARYOTIC

CELL

RAYAT SHIKSHAN SANSTHA,SATARA KARMAVEER VIDYA PRABODHINI,

MADHYA VIBHAG, SATARA

Every structure is made up of certain building blocks. It was Robert Hooke, in year 1665 first discovered these building blocks when he

observed a thin slice of cork [bark of trees ] under his self designed microscope. These compartments of cork were empty. He found they resembled the structure of honey comb and labelled them, ‘cells’ which in Latin means ‘small rooms’, but these cell were dead. There are 25 million RCBs cell. Every living thing, however different, is made up of these separate tiny units called “CELLS.”“CELLS.”


STD. & TECH-PPT



This Dutch lens grinder invented the instrument that we recognize as the microscope today.

Contributors TO THE STUDY OF CELLS

Zacharias Jansen 1590 – First invented microscope.

Robert Hooke 1665 - Discovered dead cells from cork.

Leeuwenhoek 1674 - First observed living cells of bacteria ,sperm, protozoan.

Robert Brown 1831 - Demonstrated the presence of nucleus in the cell.

Johannes Purkinje 1839- Named the fluid content of the cells protoplasm


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It was proposed by M. J. Schleiden and Theodore

Schwann [1838-39] that ‘All plants are composed of cell and cell is the basic unit of life.’ In 1885

R. Virchow modified this theory as “Omnis celula a cellula”

i.e. all cells arise from existing cells.


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- All organisms are composed of cell.- Cell is the structural and functional unit of life.- All cells arise from pre-existing cells.- Every organism starts its life as a single cell.- With discovery of electron microscope in 1940,

it was easy to understand the complex structure of a cell and its organelles.


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An egg and an amoeba both are single cells.Size of the cell varies greatly {0.1um to 18cm}The unit used to measure size of a cell is micrometer{um}1 micrometer = 1 / 1000 millimeter.

Smallest cell -

Cells of Mycoplasma galliseptium {0.1um}

Egg of an ostrich -

{18cm} is also a single, largest cell.

Some never cells in humans have one m long tail or axon.


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1. Useful molecules enter the cell. {e.g. water, salt}

2. Useful products remain in the cell.{e.g. enzymes, proteins }

3. Waste and other secretions leave the cell {e.g. carbon dioxide } and homeostasis i.e. a constant internal environment is maintained inspite of changes outside.


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Plasma membrane being of water from a region of Plasma membrane being of water from a region of high water concentration through a selectively high water concentration through a selectively permeable membrane to a region of low water permeable membrane to a region of low water concentration is called Osmosis. This is a pure concentration is called Osmosis. This is a pure mechanical process, by which the cell gains mechanical process, by which the cell gains water without spending energy.water without spending energy.

When a cell is placed into a solution of sugar or When a cell is placed into a solution of sugar or salt there are three possible situation.salt there are three possible situation.


STD. & TECH-PPT



1. Medium surrounding the cell has same 1. Medium surrounding the cell has same water concentration as that of the cell.water concentration as that of the cell.

2. Medium surrounding the cell has 2. Medium surrounding the cell has higher water concentration than that of higher water concentration than that of the cell.the cell.

3. Medium surrounding the cell has lower 3. Medium surrounding the cell has lower water concentration than that of the water concentration than that of the cell. cell.


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DiffusionDiffusion Osmosis

It occurs in any medium.It occurs in any medium. It requires liquid medium.It requires liquid medium.

The diffusing molecules The diffusing molecules can be solid, can be solid, Liquid, or gases.Liquid, or gases.

It involves movement of It involves movement of only solvent molecules.only solvent molecules.

Semipermeable Semipermeable membrane is not required.membrane is not required.

Semipermeable Semipermeable membrane is required.membrane is required.9TH 5. CELL: THE UNIT OF LIFE

SCIENCE STD.

& TECH-PPT



Chromatin fibres are thin thread like structure Chromatin fibres are thin thread like structure

Composed of DNA and proteins. DNA molecules Composed of DNA and proteins. DNA molecules

transfer the hereditary information from one transfer the hereditary information from one

Generation to the next. is called DNA.Generation to the next. is called DNA.

Functions:-Functions:-

1.1. In controls all metabolic activities of the cell.In controls all metabolic activities of the cell.

2.2. Nucleus controls cell division.Nucleus controls cell division.

3.3. It is involved in transmission of hereditary characters It is involved in transmission of hereditary characters

from parents to off springs.from parents to off springs.


STD. & TECH-PPT



1.Along with intracellular transport it also acts .1.Along with intracellular transport it also acts .as a supportive framework for a cell.as a supportive framework for a cell.

2. It synthesizes proteins and lipids and transports them. Some lipids 2. It synthesizes proteins and lipids and transports them. Some lipids synthesized by it are used in building plasma membrane while synthesized by it are used in building plasma membrane while some other lipids and proteins are used as hormones and some other lipids and proteins are used as hormones and enzymes.enzymes.

3. It transports proteins synthesized by ribosomes.3. It transports proteins synthesized by ribosomes.4. SER of certain cells of liver play a crucial role in detoxifying many 4. SER of certain cells of liver play a crucial role in detoxifying many

proteins and drugs which enter our body through food, air or proteins and drugs which enter our body through food, air or water. It makes the toxins water soluble so that they may be water. It makes the toxins water soluble so that they may be exerted through urine.exerted through urine.


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Golgi complex was first described by a GermanGolgi complex was first described by a German

scientist “ Camillo Golgi ”. It Comprises of five scientist “ Camillo Golgi ”. It Comprises of five

to eight sacs which resemble deflated balloons to eight sacs which resemble deflated balloons

placed approximately parallel to each other. placed approximately parallel to each other.


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Due to various metabolic activities goingDue to various metabolic activities goingOn in the cell, organic waste is gene rated.On in the cell, organic waste is gene rated. Lysosomes digest the waste. Lysosomes areLysosomes digest the waste. Lysosomes areSimple one membrane bound sacs, filled withSimple one membrane bound sacs, filled with digestive enzymes. These powerful enzymes aredigestive enzymes. These powerful enzymes are made by RER and are capable of digesting andmade by RER and are capable of digesting andBreaking down all organic matter. It is the cell’s Breaking down all organic matter. It is the cell’s Waste disposal system. Lysosomes are absent in Waste disposal system. Lysosomes are absent in Plant cells.Plant cells.


STD. & TECH-PPT



Mitochondria produce the energy rich Mitochondria produce the energy rich compound ATP which is the energy compound ATP which is the energy currency of the cell.currency of the cell.

The body uses the energy stored in ATP to The body uses the energy stored in ATP to synthesize chemical compounds and to do synthesize chemical compounds and to do mechanical work. mechanical work.


STD. & TECH-PPT



Vacuoles help to maintain osmotic pressure of the cell.Vacuoles help to maintain osmotic pressure of the cell. They stored metabolic byproducts and end products.They stored metabolic byproducts and end products. They stored waste products and food in animal cell.They stored waste products and food in animal cell. In plant cells, vacuoles are full of cell sap and In plant cells, vacuoles are full of cell sap and

provide turgidity and rigidity to them.provide turgidity and rigidity to them.


STD. & TECH-PPT



Documents

KARMAVEER VIDYA PRABODHINI, SATARA. MADHYA VIBHAG POWERPOINT PRESENTATION 9 TH STD.-SCIENCE & TECHNOLOGY WITH SYLLABUS 2011-12 RAYAT SHIKSHAN SANSTHA,