LIFE SCIENCES GRADE 10 CAPS STRUCTURED CLEAR PRACTICAL

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LIFE SCIENCES GRADE 10 CAPS: STRUCTURED, CLEAR, PRACTICAL HELPING TEACHERS UNLOCK THE POWER OF

LIFE SCIENCES GRADE 10 CAPS: STRUCTURED, CLEAR, PRACTICAL HELPING TEACHERS UNLOCK THE POWER OF NCS KNOWLEDGE AREA: Life at the molecular, cellular and tissue level Topic 1: Chemistry of life Microscopy: the history of microscopy and magnification

CAPS SPECIFIC AIMS 1. Knowing Life Sciences 2. Investigating Phenomena in Life Sciences 3.

CAPS SPECIFIC AIMS 1. Knowing Life Sciences 2. Investigating Phenomena in Life Sciences 3. Appreciating and Understanding the History, Importance and Applications of Life Sciences in Society

SPECIFIC SKILLS � Access information � Select key ideas Recall information Describe knowledge of

SPECIFIC SKILLS � Access information � Select key ideas Recall information Describe knowledge of NS Build a conceptual framework Organise or reorganise knowledge Write summaries Develop flow charts and mind maps Recognise patterns and trends � � � � Apply knowledge in new contexts Use knowledge in a new way Analyse information/data Critically evaluate scientific information Recognise relationships between existing knowledge and new ideas Identify assumptions Categorise information

Introduction Structure of microscope Care of microscope Use of microscope Magnification

Introduction Structure of microscope Care of microscope Use of microscope Magnification

INTRODUCTION � As we already know cells are microscopic. What does this mean? �

INTRODUCTION � As we already know cells are microscopic. What does this mean? � Scientists were able to see and study the cells because of a discovery of microscopes. � Initially botanist and zoologist were only able to study, describe, draw and label only the external structure of macroscopic organism. � This is referred to as the macroscopic view. What are macroscopic organisms?

SOLUTION � Microscopic: refers to organisms that are so small that they are not

SOLUTION � Microscopic: refers to organisms that are so small that they are not visible to the naked. � Macroscopic: refers to organisms that are visible to the naked eye.

INTRODUCTION: ROBERT HOOKE � Robert Hooke, an English scientists looked at cork tissue under

INTRODUCTION: ROBERT HOOKE � Robert Hooke, an English scientists looked at cork tissue under a very simple microscope as shown below. � He observed these cells in 1665. � As shown in the insert he saw many box like compartments. � He called these compartments cells.

INTRODUCTION: ROBERT HOOKE � The cork tissue comes from the cork plant. � However

INTRODUCTION: ROBERT HOOKE � The cork tissue comes from the cork plant. � However all he managed to see were the cell walls of the cells. � The cork cells were dead, therefore there was nothing inside these cells.

INTRODUCTION: ANTON VAN LEEUWENHOEK � He was a Dutch scientist. � He observed the

INTRODUCTION: ANTON VAN LEEUWENHOEK � He was a Dutch scientist. � He observed the bacteria under a simple microscope in 1674 as shown below.

INTRODUCTION � Three scientist, Oken in 1805, Lamarck in 1809 and Dutrochet in 1824,

INTRODUCTION � Three scientist, Oken in 1805, Lamarck in 1809 and Dutrochet in 1824, independently stated that plants and animals were made up of cells. � In 1838 Mathias Schleidan, a German scientist, was first to regard the cell as a structural unit of plants. � Then in 1839, Theodor Schwann was the first to regard the cell as the structural unit of animals.

INTRODUCTION �A German scientist, Purkinje, was the first to use the term protoplasm to

INTRODUCTION �A German scientist, Purkinje, was the first to use the term protoplasm to describe the living contents of the cell. This was in 1839. � Then 1859, another German scientist, Schultz, was the first to describe the protoplasm as the physical basis of life. � Finally, Rudolf Virchow, put forward the idea that new cells formed when existing cells divided. � These scientist were able to make these discoveries as a result of advancement in the development of the microscope.

INTRODUCTION: THE CELL THEORY � These ideas mentioned in the previous two slides developed

INTRODUCTION: THE CELL THEORY � These ideas mentioned in the previous two slides developed into what is known as the cell theory. � According 1. 2. to this theory: Every living organism is made up of cells. Every living cell comes from another.

STRUCTURE OF THE LIGHT AND ELECTRON MICROSCOPE � With your microscope at school you

STRUCTURE OF THE LIGHT AND ELECTRON MICROSCOPE � With your microscope at school you are able to see objects magnified 600 times, by using the 40 X objective and 15 X ocular lens. � The nucleus, cell membrane, cytoplasm and chloroplast were observed and named using the light microscope. � However the details of these structures were not visible because the microscope is not powerful enough.

STRUCTURE OF THE LIGHT AND ELECTRON MICROSCOPE � However in the 1930 s a

STRUCTURE OF THE LIGHT AND ELECTRON MICROSCOPE � However in the 1930 s a more powerful microscope was invented by Zworykin. � This was called the electron microscope � There are 2 types of electron microscopes. � They are the scanning electron microscope (SEM) and the transmission electron microscope (TEM) � The SEM is used to scan and view the surface of objects. � The TEM is used to see inside the objects by allowing light to pass through them.

STRUCTURE OF THE LIGHT AND ELECTRON MICROSCOPE � With the electron microscope we are

STRUCTURE OF THE LIGHT AND ELECTRON MICROSCOPE � With the electron microscope we are able to view objects 50 000 to 100 000 times. � The image is clear and not blurred. � They are able to provide such good images because they use electron beams instead of light

STRUCTURE OF THE LIGHT MICROSCOPE

STRUCTURE OF THE LIGHT MICROSCOPE

STRUCTURE OF THE LIGHT MICROSCOPE- PARTS AND THEIR FUNCTIONS. 1. 2. 3. 4. 5.

STRUCTURE OF THE LIGHT MICROSCOPE- PARTS AND THEIR FUNCTIONS. 1. 2. 3. 4. 5. Base: supports the microscope. Always place your hand under the base when transporting the microscope. Mirror: provides source of natural light. The mirror must be focused to reflect light. Illuminator/lamp: it provides an electric source of light, it is much easier to use. The condenser: it is found below the stage. Its function is to concentrate the light through the slide and specimen. Iris diaphragm: this is an opening in the condenser, it controls the amount of light falling on the specimen.

STRUCTURE OF THE LIGHT MICROSCOPE- PARTS AND THEIR FUNCTIONS 6. 7. 8. Stage: this

STRUCTURE OF THE LIGHT MICROSCOPE- PARTS AND THEIR FUNCTIONS 6. 7. 8. Stage: this is the platform on which the slide is placed. Stage/slide clips: these are metal clips that are used to hold the slide in position so that is does not move around when it is being focused. Mechanical stage: this is found in only some microscopes, it allows easy movement of the slide.

STRUCTURE OF THE LIGHT MICROSCOPE-PARTS AND THEIR FUNCTION 9. 10. 11. 12. 13. Objectives:

STRUCTURE OF THE LIGHT MICROSCOPE-PARTS AND THEIR FUNCTION 9. 10. 11. 12. 13. Objectives: these are a combination of lenses used to magnify the specimen. There are 3 different types of objectives. 4 X objectives: this is the short objectives. It magnifies the objectives 4 X 10 X objectives: this is the medium objective. It magnifies the specimen 10 X. 40 X objective: this is the long objective. It magnifies the specimen 40 X The revolving nose piece: the objectives are attached to this nose piece. Ensures the objective is in position when viewing the specimen.

STRUCTURE OF THE LIGHT MICROSCOPE-PARTS AND THEIR FUNCTIONS 14. 15. Body tube: the eye

STRUCTURE OF THE LIGHT MICROSCOPE-PARTS AND THEIR FUNCTIONS 14. 15. Body tube: the eye piece and objectives are found on it. It also links the eye piece and objectives. In other words it links and supports the optical parts. Coarse adjustment screw: used to make adjustments to focus the image. It moves the body tube up and down quickly, it provides quick focus. Used mainly at low magnification.

STRUCTURE OF THE LIGHT MICROSCOPE-PARTS AND THEIR FUNCTIONS 16. 17. Fine adjustment screw: is

STRUCTURE OF THE LIGHT MICROSCOPE-PARTS AND THEIR FUNCTIONS 16. 17. Fine adjustment screw: is used to make fine adjustments to focus the image. Used with higher magnification. Prevents damage to slide if any sudden movements are made during focusing. Eye piece/ocular: combination of lenses that are used to magnify the specimen. There are 3 oculars 5 X, 10 X and 15 X

SOMETHING FOR YOU TO DO

SOMETHING FOR YOU TO DO

SOMETHING FOR YOU TO DO: Use your notes and diagram of the microscope to

SOMETHING FOR YOU TO DO: Use your notes and diagram of the microscope to label the diagram and provide the functions of the following parts: 1. A 2. C 3. E 4. I 5. M

SOLUTION A. B. C. D. E. F. G. H. I. J. Eyepiece Coarse adjustment

SOLUTION A. B. C. D. E. F. G. H. I. J. Eyepiece Coarse adjustment screw Body tube Fine adjustment screw Nose piece Medium objective/10 X Arm Long objective/40 X Stage clip

SOLUTION K. L. M. N. 1. 2. 3. 4. 5. Diaphragm Base Light source

SOLUTION K. L. M. N. 1. 2. 3. 4. 5. Diaphragm Base Light source Short objective/4 x Eye piece-magnifies image Body tube- supports and links optical parts Nose piece- attachment of objectives Stage- platform on which slide is place Light source- provides electrical light

CARE OF THE MICROSCOPE � Follow these guidelines when handling a microscope: 1. Transport

CARE OF THE MICROSCOPE � Follow these guidelines when handling a microscope: 1. Transport the microscope by placing one hand under the base and the other holding the arm, 2. Work one hand width away from the edge of the work bench. 3. Use only soft tissue to clean the lens. 4. Always ask for help if you are unsure of anything

USE OF A MICROSCOPE Setting the light and condenser 1. Open the diaphragm fully.

USE OF A MICROSCOPE Setting the light and condenser 1. Open the diaphragm fully. 2. Look at the mirror. Notice that it has two surfaces: a plane one and a concave one. If the microscope has a built in condenser then have the plane surface of the mirror facing up. If there is no condenser then the concave surface must face up. 3. Adjust the mirror so that it faces a source of natural light. E. g. A window, open door.

USE OF A MICROSCOPE Setting the light and condenser 4. Select the lowest power

USE OF A MICROSCOPE Setting the light and condenser 4. Select the lowest power objective by turning the nose piece until you hear or feel the object click into position. 5. Place a sharp pencil on the mirror and focus until you obtain a sharp image of the pencil tip.

USE OF A MICROSCOPE Focusing at low magnification 1. Place the slide on the

USE OF A MICROSCOPE Focusing at low magnification 1. Place the slide on the stage. 2. Secure it using the clips. 3. Look through the eyepiece and slowly turn the coarse adjustment screw to focus the specimen. 4. Slowly turn the fine power objective to focus a clearer image of the specimen. 5. The slide may need to be moved to ensure the part of the specimen under examination is what you are seeing.

USE OF A MICROSCOPE Focusing at higher magnification 1. Move the next objective into

USE OF A MICROSCOPE Focusing at higher magnification 1. Move the next objective into position by carefully moving the nose piece until the objective clicks into position. 2. If the specimen is not clearly visible then use the fine adjustment screw to obtain a clearer image. 3. You may repeat the process using the next high power object if more detail is required.

USE OF A MICROSCOPE Changing the eyepiece 1. The magnification can be increased by

USE OF A MICROSCOPE Changing the eyepiece 1. The magnification can be increased by using higher power eyepieces. 2. Simply remove the existing eyepiece and replace it with one that has higher magnification power.

USE OF A MICROSCOPERECORDINGS Record what you see 1. Draw a diagram of what

USE OF A MICROSCOPERECORDINGS Record what you see 1. Draw a diagram of what you see. 2. Draw and label exactly what you see, even if many aspects are missing. 3. In many cases you do not have to draw the entire image, only a portion of it. 4. Do not forget to indicate the scale of your drawing. For example if you used the medium power objective and the 5 X eyepiece then your scale is 150 times(5 X 10) 5. Use a sharp pencil.

USE OF A MICROSCOPE- PACKING AND STORING 1. 2. 3. 4. 5. Remove the

USE OF A MICROSCOPE- PACKING AND STORING 1. 2. 3. 4. 5. Remove the slide. The 4 x objective must be in position. Replace the dust cover Place the microscope in the correct box. Store away.

MAGNIFICATION Magnification of the microscope when viewing an objective: � In order to determine

MAGNIFICATION Magnification of the microscope when viewing an objective: � In order to determine how many times the specimen viewed is magnified by we need to calculate the magnification of the microscope. � We can do this by using the following formula: Magnification power of = magnification of eyepiece X magnification of microscope lens

MAGNIFICATION � For example if you use the 10 X eyepiece and the 40

MAGNIFICATION � For example if you use the 10 X eyepiece and the 40 X objective then… Magnification = 10 X 40 = 400 X � It is usually expressed as “viewed under the microscope at 400 X. ” To determine the actual size of an object viewed under the microscope using the field of view approach.

MAGNIFICATION To determine the actual size of an object viewed under the microscope using

MAGNIFICATION To determine the actual size of an object viewed under the microscope using the field of view approach. � The field of view is the circle of light that you see when looking through the eyepiece. � The diameter maybe measured by viewing a ruler under the microscope. � The diameter for the field of view and the lens on your microscope is about 4. 5 mm or 4500μm.

MAGNIFICATION: � To calculate the length of the object you must determine the portion/fraction

MAGNIFICATION: � To calculate the length of the object you must determine the portion/fraction of the field it covers. � This can only be done by determining the number of objects that can fit in the field of view.

MAGNIFICATION � For example look at the two field of views below. X �

MAGNIFICATION � For example look at the two field of views below. X � In X X the on the right 4 of the object can fit in the field of view. � Therefore one object occupies ¼ of the field diameter.

MAGNIFICATION � Therefore the approximate length of the object can be calculated as follows:

MAGNIFICATION � Therefore the approximate length of the object can be calculated as follows: 4500 μm X ¼ = 1125 μm � The approximate length maybe calculated using the formula: Approximate length of object = fraction X diameter of field

MAGNIFICATION To determine the magnification of a drawing. 1. You need the actual size

MAGNIFICATION To determine the magnification of a drawing. 1. You need the actual size of the object drawn and the actual size of the drawing. 2. Magnification of the drawing can be calculated using the formula: Magnification of drawing = drawing size object size

MAGNIFICATION For example if your object has an actual length of 1115 μm, and

MAGNIFICATION For example if your object has an actual length of 1115 μm, and your drawing of that object has a length of 5 cm, then you , can calculate magnification of drawing as follows: First the 5 cm must be converted into μm that is 5 X 10 000 = 50 000 μm Then: Magnification of drawing = drawing size object size = 50 000/ 1115 = 45 μm 3.

MAGNIFICATION To determine the actual size of the object whose image or micrograph is

MAGNIFICATION To determine the actual size of the object whose image or micrograph is viewed using a scale line. 1. Determine what the scale line measures. 2. Assume it represents 1 μm. 3. Measure the scale line given in the drawing or micrograph. ( lets say its 15 mm) 4. Measure the length of the image in ; the drawing or micrograph. ( lets say its 50 mm) 5. Now we can use the following formula

MAGNIFICATION Actual size = measured length of object (mm) X length of scale line

MAGNIFICATION Actual size = measured length of object (mm) X length of scale line (μm) measured length of scale line (mm)) = 50 mm X 1 μm 15 mm = 3. 3 μm

TERMINOLOGY � Macroscopic: refers to organisms that are visible to the naked eye. �

TERMINOLOGY � Macroscopic: refers to organisms that are visible to the naked eye. � Microscopic: refers to organisms that are so small that they are not visible to the naked. � Field of view is the circle of light that you see when looking through the eyepiece

The platform on which the slide sits is called the… A. B. C. D.

The platform on which the slide sits is called the… A. B. C. D. Base Stage Condenser diaphragm

Opening that controls the amount of light entering the microscope A. Base B. Stage

Opening that controls the amount of light entering the microscope A. Base B. Stage C. Condenser D. diaphragm

It concentrates light through the slide and specimen: A. B. C. D. Base Stage

It concentrates light through the slide and specimen: A. B. C. D. Base Stage Condenser diaphragm

The combination of lens to magnify the image from objectives and specimen… A. B.

The combination of lens to magnify the image from objectives and specimen… A. B. C. D. Eyepiece Body tube Illuminator Mirror

It supports and links the optical parts. A. B. C. D. Eyepiece Body tube

It supports and links the optical parts. A. B. C. D. Eyepiece Body tube Illuminator Mirror

Provides support for the microscope: A. B. C. D. Base Stage Condenser diaphragm

Provides support for the microscope: A. B. C. D. Base Stage Condenser diaphragm

Provides electrical light when switched on: A. B. C. D. Eyepiece Body tube Illuminator

Provides electrical light when switched on: A. B. C. D. Eyepiece Body tube Illuminator Mirror

Provides a source of natural light. A. B. C. D. Eyepiece Body tube Illuminator

Provides a source of natural light. A. B. C. D. Eyepiece Body tube Illuminator Mirror

Attachment of objectives. A. B. C. D. Nose piece Mechanical stage Stage clips Fine

Attachment of objectives. A. B. C. D. Nose piece Mechanical stage Stage clips Fine adjustment screw

Holds the slide in position on stage: A. B. C. D. Nose piece Mechanical

Holds the slide in position on stage: A. B. C. D. Nose piece Mechanical stage Stage clips Fine adjustment screw

Allows for easy movement of slide A. B. C. D. Nose piece Mechanical stage

Allows for easy movement of slide A. B. C. D. Nose piece Mechanical stage Stage clips Fine adjustment screw

The picture below shows the microscope used by… A. B. C. D. Robert Hooke

The picture below shows the microscope used by… A. B. C. D. Robert Hooke Van Leeuwenhoek Oken Lamarck

The scientist who viewed cork cells under a simple Microscope: A. B. C. D.

The scientist who viewed cork cells under a simple Microscope: A. B. C. D. Robert Hooke Van Leeuwenhoek Oken Lamarck

The scientist that observed and described single celled organisms: A. B. C. D. Robert

The scientist that observed and described single celled organisms: A. B. C. D. Robert Hooke Van Leeuwenhoek Oken Lamarck

The electron microscope was invented by… A. B. C. D. Robert Hooke Van Leeuwenhoek

The electron microscope was invented by… A. B. C. D. Robert Hooke Van Leeuwenhoek Zworykin Lamarck

Calculate the magnification power of a microscope if you use the medium power objective

Calculate the magnification power of a microscope if you use the medium power objective and the 15 X eyepiece: A. B. C. D. 150 X 75 X 20 X

Calculate the length of an object if it covers ½ of the field of

Calculate the length of an object if it covers ½ of the field of view, assume that the diameter of the field of view is 4500μm… A. B. C. D. 2250 μm 2000 μm 4500 μm None of the above

Calculate the magnification of a drawing you have done if your drawing of the

Calculate the magnification of a drawing you have done if your drawing of the organism is 2500 μm and your drawing of it is 7 cm long. A. B. C. D. 2507 μm 28 X 0, 0028 28 μm

If you wanted to scan and view the surfaces of objects, you must use

If you wanted to scan and view the surfaces of objects, you must use the… A. B. C. D. Electron microscope SEM TEM Light microscope

If you wanted to see the inside of objects you would use the… A.

If you wanted to see the inside of objects you would use the… A. B. C. D. Electron microscope SEM TEM Light microscope

SOLUTION 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. B D C

SOLUTION 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. B D C A B A C D A C

11. 12. 13. 14. 15. 16. 17. 18. 19. 20. B B A B

11. 12. 13. 14. 15. 16. 17. 18. 19. 20. B B A B C A A B B C