Handbook b1 cell and microscope

Agastya International Foundation

Cell and Microscope Handbook B1

"By the help of Microscopes, there is nothing so small, as to escape our inquiry; hence there is a new visable World discovered to the understanding" Robert Hooke, 17th Century

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Handbook B1 Cell and Microscope OVERVIEW OF HANDBOOK ABL

CONCEPT

ABL1

Cells are the building blocks of all living organisms

ABL2

What instruments help us see tiny things?

ABL 3

What do cells do?

NO OF ACTIVITIES 2

TIME min PAGE NO 60 4

3

60

2

80

ABLs WITH REFERENCE TO STANDARD S. No 1 2 3

STANDARD 6 and 7 7 and 8 7 and 8

RELEVANT ABL ABL 1 ABL 2 ABL 3

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LIST OF FIGURES, CHARTS AND WORKSHEETS S. No Fig 1 Fig 2 Fig 3 Fig 4 Chart 1 Chart 2 Chart 3 Chart 4 Chart 5 Chart 6 Chart 7 Worksheet 1 Worksheet 2 Worksheet 3 Worksheet 4

Name Compound Microscope Appearance of coin Cells from Amoeba, Cheek and Onion Complete Factory Picture Microscopic image of onion cell Microscopic image of cheek cell Rods and Cones of the human eye Dual lenses in microscopes Microscope magnification Resolving power of microscopes Microscopic image of amoeba Parts of microscope Observation sheet ABL 1.2 Observation sheet ABL 2.2 Observation sheet ABL 3.1

Page 7 17 29 31 9 9 15 20 21 22 28 23 40 41 42

Note to Instructor: All the figures in this handbook are for the Instructor’s reference only. The Charts need to be printed and shown to the learners during the course of the activity. Worksheets need to be printed out in advance for the learners. The number of worksheets required is mentioned in the Material List.

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ABL 1: Cells are the building blocks of all living organisms Activity

Learning objective

1.1

How are big structures like buildings built?

Key messages   

1.2

Can we see cells with naked eye?

Smaller building blocks are starting materials for all kinds of structures.

The building blocks are arranged and made into a specific pattern.

The smaller building blocks are usually hard to see with the naked eye.



Cells are the building blocks of all living matter.



Cells are so tiny that we need special instruments such as microscopes to be able to see them.



Cells could not have been discovered until the invention of the light microscope. Therefore the microscope is one of the most important inventions for mankind.



The cell was first seen by Robert Hooke in 1665.

Total Time

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Time (min) 10

50

60 min

4

ABL 1.1

Time: 10 min

LEARNING OBJECTIVE How are big structures like buildings built?

Note to Instructor: In this section, we will help learners to understand that most of the things they see around them are made of smaller building blocks or units

ADVANCE PREPARATION Material List Human Body Parts Chart (or) Human Torso model

1 per class

Plant Chart (Showing Parts of Plant)

1 per class

Things to do Not Applicable Safety Precautions Not Applicable

SESSION 1.1a Link to known information/ previous activity Not Applicable Procedure Ask learners to observe some of the objects around them like a building, a sweater, a piece of cloth, or a book

UNDERSTANDING THE ACTIVITY 1.1a Leading questions 1. What are buildings made up of? (Bricks) 2. What are your clothes or sweaters made up of? (Thread/wool) 3. What are the building blocks of your books? (Pages) 4. How does the basic material (bricks/thread/pages) combine together to form the big thing?

Discussion and Explanation Discussion Item 1: Use this discussion to show the similarities between organization in non–living structures such as books, buildings, etc.

1. Bricks are arranged in rows and columns to make buildings.

2. Clothes and sweaters are made of knitting or crisscrossing thread and wool.

3. Books are made of pages stacked together.

4. Every material or big item is made of several smaller items (e.g. pages, wool, and bricks). These “smaller items” are often similar. We put many of them together to make the big thing.

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5 To make a big thing, we often use specific arrangements. For e.g., if we just piled bricks, it would not make a building. If we simply threw paper together in any order, it wouldn’t be a proper book.

If we just mixed threads of all varieties and sizes, we wouldn’t get cloth.

Therefore, to make a big thing, we need lots of small building blocks and arrange them in a specific pattern.

SESSION 1.1b Link to known information/ previous activity In the previous activity we saw how non living things are made from smaller blocks. Now let us look at living things.

Procedure Display chart of human body or chart of plant parts. Point to the various parts, as learners respond to leading questions.

UNDERSTANDING THE ACTIVITY 1.1b Leading questions 1. What do you think our body is built of?

2. What are all those parts made of?

3. What is each part made of?

4. Can you compare this to non living objects like books and buildings?

Discussion and Explanation Discussion Item 1:Discuss what living things like plants and human being are made of. Use this discussion to highlight structural organization in living things and how they are similar to non-living things.

We looked at how non-living things like houses and books are made up of smaller building blocks. Let’s look at what living things like plants and human beings are made of  Our body is made of parts such as hands, legs, and head.  These parts are made of organs such as blood, muscles, bones, stomach, intestine, brain- organs.  Each part may be made of smaller parts.  We discussed how books are made of pages that were made of fibers.

Buildings are made of bricks. In turn, bricks are made of clay.

Similarly, livings things like humans are made of many organs. Each organ is made of tinier parts.

In general, we make big things by taking smaller components and arranging them in an organized, structured way.

We cannot see each individual clay particle in a brick. Nor can we see each individual fiber on a page or our clothes.

Similarly, we are unable to see the tiny parts of our own bodies.

KEY MESSAGES   

Smaller building blocks are starting materials for all kinds of structures The building blocks are arranged and made into a specific pattern The smaller building blocks are usually hard to see with the naked eye

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Time: 50 min

ABL 1.2 LEARNING OBJECTIVE -What is living matter made of?

Note to Instructor: In this section, you will be guiding learners on how to use the microscope to see simple cells. This will be a new experience for most of them and there will be a lot of excitement in the class.

ADVANCE PREPARATION Material List Empty Slides Onions with outer shells Tissue paper Microscope Magnifying lens Ice cream sticks Bowl/plastic cup with water Dropper Forceps Drawing Sheet Laminated images of microscope images (onion cell) Laminated images of microscope images (cheek cell) Observation sheet Methylene Blue

3 per group 2 – 3 per group 1 per group 1 per class 1 per group Few per group 1 per group 2 per group 1 per group 1 per student 1 large chart 1 large chart 1 per learner Few drops

Things to do Not Applicable Safety Precautions The microscope will be handled only by the Instructor, please follow points given below  Always carry the microscope with two hands – one on the arm and one underneath the base of the microscope. Hold it up that it does not hit tables or chairs. Never swing the microscope.  Do not touch the lenses. If they are dirty, use special lens paper to clean the lenses.  If using a microscope with a mirror, do not use direct sunlight as the light source –it may result in eye damage. If using a microscope with a light, turn off light when not in use.  If using a lighted microscope, turn off light before pulling out the plug.  Be careful when handling glass slides and cover-slips. Please handle broken glass with care.  Always clean slides and microscope when finished.  Store microscope set on the lowest objective with the nosepiece turned down to its lowest position (using the coarse adjustment) Agastya International Foundation . For Internal Circulation only.

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Figure 1: Compound Microscope

SESSION Link to known information/ previous activity In the previous activity, we saw that smaller building blocks are starting materials for all kinds of structures. However these building blocks, especially in living organisms, can be very hard to see with the naked eye.

Procedure Divide learners into 4 groups.

Distribute material to each group and ask them to prepare slides  Slide 1 – Onion Slide o Using forceps or two fingers, gently peel the onion skin and drop it in a bowl of water so that it does not fold or dry o With dropper, put a few drops of water on the slide o With forceps, pick up a piece of onion skin soaked in water  Slide 2 – Buccal Cavity o One learner from group must use a ice cream stick to gently scrape cells from inner cheek o Place some scrape on a fresh slide along with a drop of water o Add a small drop of methylene blue to stain the cells  Slide 3 – Tissue paper slide o Tear a small square of tissue paper and place on the slide  

After preparing slides, 1 group goes towards the microscope to view slides Meanwhile, other groups must examine their samples through o Naked eye

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

o Magnifying glass These groups must make drawings on the observation sheet.

After 10 minutes, next group goes to microscope to view all three slides The first group comes back from the microscope and makes drawings of what they saw through the microscope on the observation sheet.

At the end of the activity, all groups must complete drawings of how their specimen looks through o Naked eye o Magnifying glass o Microscope There is a story of the microscopes and discovery of cell given in the interesting information section below. Read it out in an interesting and engaging way

UNDERSTANDING THE ACTIVITY Leading questions 1. What happens when you saw the onion peel through a magnifying glass and then a microscope?

2. Do you see any repeating structures in the onion peel?

3. What did you see in your cheek cells?

4. What do you think you are seeing?

Discussion and Explanation Discussion Item 1: What do you observe when you looked at onion cells, cheek cells and tissue paper under a microscope?

1. The specimen appeared bigger through magnifying glass. It became even bigger through microscope.

2. In the microscope, we were able to see repeating structures that looked like bricks.

Each of those bricks had a small dot towards the corner.

3. In cheek cells, we saw several small round objects. Again, each of them had a big dot in the center.

4. What you are seeing are the building blocks of all living matter. They are called “cells” If you compare what you saw in the buccal cavity (cheek cells), the onionskin and the tissue paper, you will see that they are made of a number of smaller parts fitting together in a pattern.

For living things, you would have seen small compartments (circular or brick like). These tiny blocks are called cells These “cells” are so tiny that we need special instruments to be able to see them.

Chart 1: Microscopic image of onion cell

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Chart 2: Microscopic image of cheek cell

Leading questions Would it have been possible for us to see the cells without the help of a microscope?

Discussion and Explanation Discussion Item 2: The story of the discovery of cells 1. Until microscopes were invented, no one had seen a cell. We did not know what living matter was made of. One day, Hans and Zacharias (pronounced za-kuh-RYE-us) Janssen from Holland invented the microscope.

With the microscope, curious people all over the world started examining things under the microscope – some looked at plants, others looked at animals and few more people looked at pond water.

In 1665, an English scientist named Robert Hooke looked at cork slices under the microscope. He found tiny structures that resembled a monks resting place. In Latin, the language spoken at that time, those resting places were called cells. So he named these tiny structures “cell”. Though no one speaks Latin anymore, we still use the word “cell”.

Soon many scientists were examining things under the microscope. Whenever they saw living matter - whether plants, animals, or little organisms in pond water, they ALWAYS found these tiny structures.

This is how we concluded that living matter is made up of cells.

KEY MESSAGES    

Cells are the building blocks of all living matter.

Cells are so tiny that we need special instruments such as microscopes to be able to see them.

Cells could not have been discovered until the invention of the light microscope. Therefore the microscope is one of the most important inventions for mankind.

The cell was first seen by Robert Hooke in 1665.

LEARNING CHECK Distribute learning check worksheet to assess students on ABL1. The answer key is provided here for your reference.

1. The fundamental unit of all living beings is the cell A. True (Answer) B. False 2. When you prepared slides of cheek cells, why was it necessary to add a small drop of methylene blue to stain the cells?

A. This activates the cells even if they are dead Agastya International Foundation . For Internal Circulation only.

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10 B. To observe the parts of a cell more clearly as they are transparent otherwise (Answer) C. Cells cannot be viewed under the microscope otherwise D. None of the above 3. When you observed the cheek cells and the onion cells, how did they differ?

A. The cheek cells were more rectangular, while the onion cells were more irregularly shaped.

B. The cheek cells had a boundary wall, while the onion cells did not C. The cheek cells are more irregular in shape, while the onion cells are more regular in shape (Answer) D. The onion cells were much smaller than the cheek cells 4. When you observed slides of the onion peel, the cells resembled which of the following structures?

A. Brick wall (Answer) B. Beaded chain C. Stack of books D. Droplets of water 5. When you observed the cheek cells and the onion cells, what were the similarities that you noticed?

A. Both the cell structures looked rectangular B. Both the cell structures were similar in size C. Dot like stains were observed in both types of cells (Answer) D. None of the above

TRY IT YOURSELF A) After this ABL, have a group discussion with your classmates about why you think it is important to learn about the cells.

For Instructors: The answer is that studying cells helps us understand how organisms, including humans, function.

After all, our bodies are made up of trillions of cells. By learning about cells, we come to understand how we can • protect cells to prevent infection and other harmful effects • observe cells to diagnose disease • treat cells to heal illnesses • stop harming cells through our choices and actions.

INTERESTING INFORMATION 



A group of researchers in Europe has taken on the mind-boggling challenge of creating an artificial cell that can replicate on its own and even evolve under certain conditions. In other words, their goal is to create the world’s first robotic cell. To achieve their goal, these researchers will have to create artificial components that mimic the components found in a real cell. Only by studying real cells will they be able to create the perfect fake!

Malaria is a deadly disease. It is transmitted by mosquitoes in tropical parts of the world. Scientists have recently developed a vaccine that can protect human cells from malaria infection. To develop this vaccine, scientists needed to learn about cells in both humans and mosquitoes. They also needed to understand the single-celled organism that causes malaria.

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11   

The biggest cell in the world is the ostrich egg, which can be seen with your naked eye! Weighs about 1.4 kilograms, is equivalent in volume to 2 dozen chicken eggs.

The human body is made up of trillions of cells. Cells of the nervous system, called nerve cells or neurons. The longest cell of human body is the motor neuron which is about 4 ft 3 in (1.3 m) long.

The story of microscopes and discovery of cell

Hans and Zacharias Janssen from Holland invented the microscope. Imagine if you were one of the first people ever to have a microscope? Wouldn’t you be curious and examine every little thing in the microscope? That is what the scientists did.

Take the English Scientist Robert Hooke. He started looking at cork slices under the microscope. He found tiny structures that looked like honeycombs. It reminded him of monks’ resting places which were called “Cell” in Latin. So he called the structures in the cork slices “Cell”.

Another Dutch Scientist in 1680 would examine all sorts of things under the microscope. He looked at blood. He looked at drops of rain. He even scraped his teeth and placed them under the microscope. Like Robert Hooke, he found tiny structures that seemed to swim and move and have a life of their own. He called these organisms “animalcules” because they resembled tiny animals.

Two centuries later in 1838, scientists were still looking at things under the microscope. Matthias Schleiden, a botanist from Germany looked at plants. And they too had cell like structures. And Theodor Schwann, a zoologist from Germany examined animal cells in 1839. He too found cells. Again and again, no matter what living matter you looked at – be at moss or plants or animals or us or even tiny organisms in water droplets – they all had cells.

Scientists had discovered something very special about all the organisms in the living world. They were all made of cells!

WEB RESOURCES   

http://www.bbc.co.uk/bitesize/ks3/science/organisms_behaviour_health/cells_systems/revision/2 / http://www.youtube.com/watch?v=PrX3h-AflZI http://www.youtube.com/watch?v=i2x3MKSJez4

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REFERENCES Figure 1: http://schaechter.asmblog.org/.a/6a00d8341c5e1453ef01675e9c3596970b-popup Figure 2: http://www.appliancesonlineblog.com.au/wpcontent/uploads/2012/08/onion-cells.jpg Figure 3: http://mrsdlovesscience.com/cheek_cell_smear.jpg http://schools.cbe.ab.ca/b682/pdfs/Science%208/Cells&Systems.pdf http://www.mcgrawhill.ca/web_resources/sch/SL10_sample_unit1_topic1_1.pdf

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ABL 2 Magnifying lenses & microscopes make small things look bigger Activity

Learning objective

2.1

How big (or near) should objects be for our eyes to see them?

Key messages 

There is a limit to what our eyes can see.



In order to view small objects, they must be placed very close to the eye.

In order to view large objects, they must be kept at a distance away from the eye Tools like magnifying glasses help make images look bigger Image enlargement depends on type of lens, curvature of lens and how far the object is compared to the lens A microscope uses 2 magnifying lenses to make the object appear bigger Total Time



2.2

2.3

What tools are used to make things appear bigger?



How do compound microscopes work?





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Time (min) 10

20

30

60 min

14

ABL 2.1

Time: 10 min

LEARNING OBJECTIVE - How big (or near) should objects be for our eyes to see them?

Note to Instructor: The simple experiments in this section will help to understand the basic principles of how we see things. It will also help learners to observe and learn from simple daily activities – for example, why do we bring things close to our eyes to see them more clearly.

ADVANCE PREPARATION Material List Paper

1 per group

Pin

1 per group

Human Eye Chart (Chart 3 or model of

One per class

eye) Things to do Not Applicable Safety Precautions Not Applicable

SESSION Link to known information/ previous activity In the previous exercise, we learnt that our eyes do not see everything. We’ll look at what makes it possible for us see things with our eyes.

Procedure Distribute material to each group.Nominate one learner from each group. This learner secretly pricks a tiny hole on a piece of paper; s/he must not reveal to the remaining learners where the hole has been placed.

Take the pricked sheet far away from other learners and ask the other learners to answer the following questions.

Can you see the full sheet?

Can you find where a hole has been pricked?

Nominee takes a step closer and asks the two questions again Repeat until learners are able to see the hole clearly

UNDERSTANDING THE ACTIVITY Leading questions 1. When you want to see a small object fully what do you do?

2. When you want to see a big object fully what do you do?

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15 Discussion and Explanation Discussion Item 1: There is a limit to what your eyes can see Ability to see an object depends on the distance of the object from the eye The hole could be seen only when the paper was close to the eye To see a big object, the object must be far away so that we can see itfully To see a small object, the object must be close enough for us to see it fully Explain with chart/model of eye: The human eye is made up of a lens that captures light. That light that passes through the lens falls on the retina that is present behind the lens. The retina is made up of cells called cones and rods. There are 6 million cones (60 lakh) and 120 million rods (1200 lakh)

Chart 3: The Rods and Cones of the Human Eye

Rods are sensitive to very small amounts of light and can help us see in the dark.

Cones require more light. They help us see exactly where things are, how big things are, and what color they are.

For us to see things clearly, the image must cover at least 1 full cone.

When the paper was far, the image of the hole was so small that it did not cover even 1 cone. Only when the paper got closer, were we able to see it.

Again when the paper was very close to us, the image of the hole was big enough for it to fall on one or more cones. But the paper was so big that the light fell outside the boundary of the lens. If light did not pass the lens, it would not fall on the retina. So we were not able to see it.

Today, we rely on other external tools that make images bigger and smaller.

KEY MESSAGES   

There is a limit to what our eyes can see.

In order to view small objects, they must be placed very close to the eye.

In order to view large objects, they must be kept at a distance away from the eye

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ABL 2.2 Time: 20 min

LEARNING OBJECTIVE-What tools are used to make things appear bigger?

Note to Instructor: In this section, you will show learners how a simple glass of water acts like a lens and makes an object look bigger than its actual size

ADVANCE PREPARATION Material List Materials Glass filled with water Marker pen Coin Magnifying Glass Ruler/Scale Observation chart

Quantity 1 per group 1 per group 1 per group 2 per group 1 per group 1 per learner

Things to do Make sure that you give the same size of coin to every group Safety Precautions Handle delicate things such as glass, with care.

SESSION 2.2a Link to known information/ previous activity In the earlier activities, we have seen how things looked bigger when we used a magnifying glass or a microscope. Let us now try to understand how this happens through a simple experiment Procedure Divide the class into 4 - 5 groups. Distribute material to groups. Each student gets an observation chart.

Have the students perform the following activity.

Hold the coin in front of the glass filled with water and mark its outlines on the front of the glass Measure the diameter of the circle Hold the coin behind the glass and mark its outlines on the front of the glass Measure the diameter of the second circle Note down these measurements in observation sheets (Part 1)

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Figure 2: Appearance of coin

UNDERSTANDING THE ACTIVITY 2.2a Leading questions 1. Is there any change in the size of the coin when viewed through the water?

2. What is the glass of water doing to the image of the coin?

Discussion and Explanation Discussion Item 1: The round water filled glass is acting like a magnifying lens 1. The coin appears wider The coin appears bigger on one side The shape of the coin is changed 2. When light from coin is passing through the glass of water, it is bent such that the image looks bigger The round water filled glass is acting like a magnifying lens

SESSION 2.2b Procedure Ask learners to observe a 5 rupee coin through a. naked eye b. magnifying glass Learners should draw its image on given observation sheet (part 2)

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UNDERSTANDING THE ACTIVITY 2.2b Leading questions 1. What is the magnifying glass doing?

2. Move the coin further away from the magnifying glass. Does the image become larger or smaller?

3. When you compare how big the coin was when viewed through the magnifying glass and glass of water, is the image the same size?

Discussion and Explanation Discussion Item 1: Magnifying glass enlarges the size of the object It makes the 5 rupee coin look much bigger.

1. The magnifying glass consists of a lens that bends light that is coming through it and makes images appear bigger.

2. When light passes through objects that are denser than air like water, glass, air, a process called refraction happens and the path of the light is bent. This results in a magnified image of objects.

3. Not all material magnifies images to the same extent. Different materials bend light to different extents. Further, if the material itself is bent, it can bend light in different ways. Finally, depending on where the object is compared to the lens, image can be magnified to different extents.

KEY MESSAGES  

Tools like magnifying glasses help make images look bigger by bending light.

Image enlargement depends on type of lens, curvature of lens and how far the object is compared to the lens.

Time: 20 min

ABL 2.3 LEARNING OBJECTIVE-How do compound microscopes work?

Note to Instructor- In this experiment, learners will observe how two lenses will help us to get greater magnification. This is the basic principle of the compound microscope.

ADVANCE PREPARATION Material List Materials Glass filled with water Marker pen Coin Magnifying Glass Ruler/Scale Observation chart

Quantity 1 per group 1 per group 1 per group 2 per group 1 per group 1 per group

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19 Chart4

1 per class

Chart 5 on Microscope magnification

1 per class

Chart 6 on Resolving power of microscopes

1 per class

Things to do Not Applicable Safety Precautions Not Applicable

SESSION Link to known information/ previous activity In the previous activity you learnt that magnifying glasses help make images look bigger by bending light.

Now, what happens if we used two lenses?

Procedure Combine 2 groups from ABL 2.2 so that each group now has 2 magnifying lenses. Have the students perform the following activity.  First look at the coin/button with 1 lens. Move lens until a clear image is formed. Mark edges of the coin/button  While 1 learner holds lens in the same position, ask another learner to place a lens on top of the first lens. Adjust the second lens only until a clear image is formed.  Mark the edges of the image

UNDERSTANDING THE ACTIVITY Leading questions 1. Do you see any change in the size of the coin/button after using first lens?

2. Is the size increased or decreased after using the second lens?

Discussion and Explanation Discussion Item 1: What happens to the image of an object, if two magnifying lenses were used?

1. Like last time, size of the coin increased when we looked through the first lens 2. When we included one more lens in the path, the size increased even more In the last activity, we learnt we could use a magnifying lens to make images appear larger.

When we add an additional magnifying lens, it magnifies the image from the first lens making it appear even larger In fact, microscopes are able to achieve such high magnifications because they use two lenses.

Microscopes that use 2 lenses are called “compound microscopes” Instructor shows a chart to explain working of a microscope In a microscope, the lens closer to the object or specimen (in this case, the button or coin) is called the objective.

If you look closely, you’ll see two types of lenses. On one it says 10x. This means that it makes the image 10 times bigger.

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20 On another lens, it says 40x. This means, it makes the image 40 times bigger.

Chart 4 Dual Lenses in Microscopes.

Discussion Item 2: Using a microscope describe various parts of a microscope to the student. Refer to Figure 1 for various parts.     

The 10x piece is usually called coarse objective – because it does a very “rough” or “coarse” magnification.

The 40 x piece is called the fine objective – because it helps to see the object very clearly.

The second lens closer to the eye is called eyepiece. Its magnification is 10 x.

Using the 2 lenses, you can see an image that is up to 400 times bigger than the object.

When you see an image, think to yourself: the actual object is 400 times smaller than what you’re seeing.

Discussion Item 3: Use these charts to discuss how by increasing magnification and using powerful microscopes, we can see very tiny objects such as cell organelles in great detail.

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Chart 5: Microscope Magnification   

Some microscopes also have a 100x eyepiece. With that, you can see objects up to 1000 (100x10) bigger. (Chart 5) Sometimes objects are particles are so tiny that even after magnifying them 1000 times, the image is still not large enough for us to see.

To see them, we use some powerful microscopes called electron microscopes. With electron microscopes we can see what is inside the cell. (Chart 6)

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Chart 6: Resolving Power of Microscopes

KEY MESSAGES 

A microscope uses 2 magnifying lenses to make the object appear bigger.

LEARNING CHECK Provide the sheet, ask learners to label the various parts of the microscope

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Worksheet 1: Parts of Microscope

Key: Refer to Figure1 for answers.

TRY IT YOURSELF A)Microscope Forensics (http://www.hometrainingtools.com/microscope-forensics-scienceproject/a/1537/) When investigators are at the scene of a crime, they look for the smallest pieces of evidence, and then analyze them under a microscope in the lab. Some of the things they might look at are fibers from clothing or carpet, hair, soil tracked in on shoes, fingerprints, and blood stains. Those don't seem like they'd tell you much, but under a microscope, surprising details come to light.

Materials     

Compound microscope Magnifying glass Plain glass slides Paper and #2 pencil Fingerprints

Why do the police use fingerprints to help identify criminals? For one thing, it's evidence that is easy to find - we leave prints behind us every time we touch a smooth surface without gloves. The amazing thing is that every person's fingerprints are unique. There is no one else who has the same fingerprint as you!

When prints are left behind at a crime scene, police first have to show that they weren't left behind by someone who was supposed to be there. If your house was robbed, for example, they would probably take Agastya International Foundation . For Internal Circulation only.

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24 fingerprints from everyone in your family to help them identify and rule out all the prints that didn't belong to the thief.

1.Make a fingerprint library of you and your family members (or classmates). One easy way is to rub a newly sharpened pencil across a piece of paper about 20 times until you have a nice layer of graphite (pencil lead). Then rub your fingertip in the graphite and press your finger down on a piece of scotch tape.

Then you can stick the scotch tape down on a fresh piece of paper and label which finger it was a print from.

2.Look at your fingerprints with a magnifying glass. What kind of pattern do you see? The most common patterns are called arch, whorl, and loop; go here to see http://ridgesandfurrows.homestead.com/fingerprint_patterns.html 3.Your prints may look very similar to someone else in your family. Try taking a print and sticking the tape on a glass microscope slide and use a microscope to look for tiny differences between the prints.

There are two types of fingerprints, visible and latent. Investigators use two different methods to lift these prints from a surface. Learn how to use both methods in our Forensic Science Experiments article. http://www.hometrainingtools.com/forensic-science-projects/a/1227/ B) Ask a Microscopist If you have access to the web, you can ask a question to a Microscopist http://www.microscopy.org/microscopy/ask.cfm

INTERESTING INFORMATION



Scanning Electron Microscopes (SEMs) scan the surface of an object to magnify it by up to 100,000 times.

WEB RESOURCES http://sciencespot.net/Pages/classbio.html#micro

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VOCABULARY AND DEFINITIONS

Eyepiece: The lens the viewer looks through to see the specimen. The eyepiece usually contains a 10X or 15X power lens.

Diopter Adjustment: Useful as a means to change focus on one eyepiece so as to correct for any difference in vision between your two eyes.

Body tube (Head): The body tube connects the eyepiece to the objective lenses.

Arm: The arm connects the body tube to the base of the microscope.

Coarse adjustment: Brings the specimen into general focus.

Fine adjustment: Fine tunes the focus and increases the detail of the specimen.

Nosepiece: A rotating turret that houses the objective lenses. The viewer spins the nosepiece to select different objective lenses.

Objective lenses: One of the most important parts of a compound microscope, as they are the lenses closest to the specimen.

A standard microscope has three, four, or five objective lenses that range in power from 4X to 100X. When focusing the microscope, be careful that the objective lens doesn’t touch the slide, as it could break the slide and destroy the specimen.

Specimen or slide: The specimen is the object being examined. Most specimens are mounted on slides, flat rectangles of thin glass.

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26 The specimen is placed on the glass and a cover slip is placed over the specimen. This allows the slide to be easily inserted or removed from the microscope. It also allows the specimen to be labeled, transported, and stored without damage.

Stage: The flat platform where the slide is placed.

Stage clips: Metal clips that hold the slide in place.

Stage height adjustment (Stage Control): These knobs move the stage left and right or up and down.

Aperture: The hole in the middle of the stage that allows light from the illuminator to reach the specimen.

On/off switch: This switch on the base of the microscope turns the illuminator off and on.

Illumination: The light source for a microscope. Older microscopes used mirrors to reflect light from an external source up through the bottom of the stage; however, most microscopes now use a low-voltage bulb.

Iris diaphragm: Adjusts the amount of light that reaches the specimen.

Condenser: Gathers and focuses light from the illuminator onto the specimen being viewed.

Base: The base supports the entire structure.

REFERENCES Figure 4: http://starizona.com/acb/ccd/advimages/eye01.gif Figure 6: http://micro.magnet.fsu.edu/primer/images/magnification/compound.jpg Figure 7: http://www.connecticutvalleybiological.com/images/ch4860.jpg Figure 8: http://www.sciencelearn.org.nz/var/sciencelearn/storage/images/contexts/exploring-withmicroscopes/sci-media/images/resolving-power-of-microscopes/639092-3-eng-NZ/Resolving-power-ofmicroscopes.jpg Figure 9: http://www.buzzle.com/images/diagrams/microscope/blank-microscope-diagram.jpg Figure 10: http://www.microscopy.org/microscopy/ask.cfm

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ABL 3 Understanding the structure and function of the cell and its parts Activity

Learning objective

3.1

Do all living organisms have similar cell?

3.2

How do cells work?

Key messages 

Cells come in a variety of shapes, sizes and numbers  Unicellular organisms have only one cell, while multicellular organisms have many cells  Cells work like a factory.  Cells contain organelles, each of which perform a specific function  Compared to animal cells, plant cells have cell walls, chloroplasts and a large vacuole.

Total Time

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Time (min) 20 min

60 4 i

n 60 min

28 Time: 20 min

ABL 3.1 LEARNING OBJECTIVEDo all living organisms have similar cells?

Note to Instructor:In this section, we will help learners see how cells of different organisms are different.

ADVANCE PREPARATION Material List Materials Microscope Permanent slides of amoeba, euglena or paramecium Laminated, blown-up sets of microscopic images Observation sheet

Quantity 1 1 1 set per group 1 per learner

Things to do Not Applicable Safety Precautions Instructor to handle microscope.

SESSION Link to known information/ previous activity You had observed cheek cells and onions under the microscope in the previous activity. Let us now compare them.

Procedure Divide learners into groups of 6 learners. Distribute set of laminated microscopic images to each learner.

Distribute observation sheets. Each group takes turns viewing amoeba slide through microscope. They must also make drawings of microscopic images on their observation sheets.

Chart 7: Microscopic view of Amoeba

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UNDERSTANDING THE ACTIVITY Leading questions 1. So far you’ve looked at cells of an organism called amoeba, your own cheek and onions.

How is each of the cells different?

2. Which cells are bigger and which cells are smaller?

3. Can you notice a distinct wall in onion cells?

4. How will you describe the cheek cells?

Discussion and Explanation Discussion Item1: How did the cells appear under the microscope?

1. Amoeba cell was the biggest and irregularly shaped Onion cell was the next biggest. It was like a brick with a dot in the corner.

Cheek cells were somewhat rounded and the smallest cells. They had a dot in the centre Cells come in many shapes, forms and sizes Discussion Item 2: Organisms can be made of 1 or more cells The amoeba is an organism where the entire organism made of only 1 cell.

Figure 3:Cells from Amoeba, Cheek and Onion The onion peel was made of rows and rows of cells. You know that the onion itself is part of a larger plant with a stem and root and leaves. Each of those parts has more cells. Such types of organisms are called multicellular organisms.

Similarly, you observed cheek cells and found many of them. Again, you know that cheek is only one part of our body. We have nose, eyes, a stomach, heart and other organs, like onions, they are multicellular.

KEY MESSAGES  

Cells come in a variety of shapes, sizes and numbers Unicellular organisms have only one cell, while multi-cellular organisms have many cells.

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ABL 3.2

Time: 40 min

LEARNING OBJECTIVE - How do cells work?

Note to Instructor: In this section, learners will understand the different parts of the cell and its functions through a simple activity. Here we will compare different parts of the cell to different departments of a factory

ADVANCE PREPARATION Material List Materials Chart paper (1/2 sheet) Chart paper Cell factory analogy cards Cell factory analogy cards Cell factory picture Cell organelles (from ppt handout) Animal cell with parts Plant cell with parts Fevicol Markers/Sketch pens Soap solution Bubble wire frame to make and blow bubbles

Quantity 1 per group Full sheet 1 for instructor 1 full set per group Each card, the size of a visiting card.

1 set for instructor Each card, the size of a photo 1 large print-out stuck on chart paper per class 1 full set per group 1 large set per instructor 1 large print-out and model 1 large print-out and model 1 small tub per group 1 set per group 15 ml per group 1 per group

Things to do Soap Solution 1 liter of soap solution to be prepared as follows: Vim liquid (1/2 l) + 50 ml glycerol + 5 shampoo sachets + ½ Liter water Safety Precautions Not Applicable

SESSION 3.2a Link to known information/ previous activity Humans have a stomach for digestion, nose and lungs for breathing and skin for protection. Each of these organs is made of cells specific for that function. But if bacteria have to survive as a single cell, it must be capable of eating, breathing and protecting itself too. How does a single cell manage all that?

Procedure  Divide learners into 6 groups. 3 of the groups are plant cells.

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31          

Ask learners to name themselves with a plant name (e.g. banyan, banana, rose etc.)

3 of the groups are animal cells. Ask learners to name themselves with an animal name (e.g. horse, cat, and bear).

Distribute ½ sheet cardboard and cell factory analog cards.

Ask students to turn the analog cards to the printed side Place a large cardboard sheet in front of the class.

Put across the leading questions given in the section below.

With each learner response, choose the appropriate analog card and pin it on the cardboard sheet.

At the same time ask the learners to choose that analog card and stick it on their sheet. Then move on to the next learner response.

Repeat above steps.

As far as possible, maintain the same arrangement (not order) as the “complete factory picture”.

Figure 4: Complete Factory Picture



When learners complete the responses, and all people/departments are identified, display the “complete factory picture” next to the assembled cardboard sheet.

UNDERSTANDING THE ACTIVITY 3.2a Leading questions Let us imagine that the cell is a factory that makes a special product called proteins. What kind of people and departments do factories need?”

Discussion and Explanation Discussion Item 1: Some of responses that you probably get from the students are: 3. Managers 4. Workers 5. Assembly/Production 6. Kitchen/ Raw material 7. Electricity/energy 8. Waste disposal 9. Packaging 10. Distribution

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32 Just like how we have all these departments in a factory, we have these departments in a cell too. In fact, for cells we have special names for each of these departments. Although they may look very different from a typical factory, they perform the same functions.

SESSION 3.2b Link to known information/ previous activity We had identified the various departments in a factory. Let us now compare the parts of the cell (or the organelles) to these departments.

Procedure Identify cell organelle from your set Explain what the organelle does to the students (see Discussion and Explanation section below) On the cell factory displayed to the class, stick the cell organelle (on one edge only) on top of the corresponding cell factory Note name of the cell organelle below Give learners 2 – 3 minutes to study cell organelle corresponding to the factory part from their own card sets.

Ask them to stick the cell organelle on the cardboard sheet (on one edge only) with fevicol If group is a plant cell, they must stick only those organelles that are in the plant cell Plant cell participants must stick all organelles only in the border of the cell and must keep the center empty If group is an animal cell, they must stick only those organelles that are in the animal cell Label the part with marker/sketch Proceed to next organelle

UNDERSTANDING THE ACTIVITY 3.2b Leading questions How is the factory protected?

Discussion and Explanation Discussion Item 1: Cell Membrane This is like a “wall” or “boundary” of the cell. It has special channel for entry and exit guarded by proteins.

This is like a factory compound wall and the guarded gate.

Tip: Link to previous microscopic activity. When you inspected your cheek cell, you noticed small irregular (circular) shaped cells with a somewhat thick border. This border is the cell membrane. All cells have cell membranes.

Not all factories have the same kind of outer protection. Some factories may have a simple wall. Others may have a large, high wall. Others may have a barbed wire fence. Similarly, some cell factories have additional boundaries apart from a cell membrane. Such additional boundaries are found in plants and are Agastya International Foundation . For Internal Circulation only.

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33 called “cell walls”. They ensure that the cells are rigid and stiff. It’s what helps plants stay stiff and upright despite not having bones and skeletons.

Tip: Link to previous microscopic activity. When you inspected onion peel cells, you noticed a thick hexagonal border. This is the cell wall. Within the cell wall, the cell also has a cell membrane. Unlike onion peel cells from plants, cheek cells from animals do not have cell walls. Only plant cells have cell walls.

SESSION 3.2c Link to known information/ previous activity In the previous activity we identified the cell membrane. Let us perform an activity to study an important property of the membrane.

Procedure Blow a bubble using the wire frame Form a soap film by dipping the wire frame into soapy water Try and insert a wet finger into the wire frame Try and insert a dry finger into the wire frame

UNDERSTANDING THE ACTIVITY 3.2 c Leading questions 1. What happens when you insert a wet finger?

2. What happens when you insert a dry finger?

Discussion and Explanation Discussion Item 1:   

We’re able to insert a wet finger without breaking the bubble When we insert a dry finger the bubble bursts The soap bubble just blown is actually like a cell Just like the soap film is holding together some air, a cell membrane holds together the entire factory Imagine it was filled with all the departments of a factory When we insert a wet finger, nothing happens to the bubble. But it bursts for the dry finger. So some material can pass through the bubble, while other material can’t. Such a membrane is called semi-permeable membrane. Cell membranes are like these soap bubbles. They are also semi-permeable membranes.

SESSION 3.2d Link to known information/ previous activity We had identified a few of the organelles, let us look at the other organelles and their functions.

Procedure  Identify cell organelles from your set  Explain what the organelle does to the students (see Discussion and Explanation section below) Agastya International Foundation . For Internal Circulation only.

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34         

Stick the cell organelle (on one edge only) on top of the corresponding cell factory Note name of the cell organelle below Give learners 2 – 3 minutes to study cell organelle corresponding to the factory part from their own card sets.

Ask them to stick the cell organelle on the cardboard sheet (on one edge only) with fevicol If group is a plant cell, they must stick only those organelles that are in the plant cell Plant cell participants must stick all organelles only in the border of the cell and must keep the center empty If group is an animal cell, they must stick only those organelles that are in the animal cell Label the part with marker/sketch Proceed to next organelle

UNDERSTANDING THE ACTIVITY 3.2d Leading questions Can you try to relate the various departments of the factory to those of the parts found in a cell?

Discussion and Explanation Discussion Item 1: Cytoplasm The cytoplasm is the entire working area inside a factory. This is where workers move around, where all the departments are built, where raw material is stored and placed. The cytoplasm is surrounded by the cell membrane.

When we blew a bubble, a soap film held air together. Similarly, the cell membrane holds together cytoplasmic jelly in which all the departments float around.

Tip: Link to microscope activity. The empty space you saw in your cheek cell or onion peel cells is actually filled with a jelly like substance called cytoplasm. It is the working area of the cell where all the departments are floating and all the raw material is placed.

Note: The entire cardboard sheet the learners are working on can be considered the cytoplasm.

Nucleus The nucleus is comparable to the headquarters of the factory where managers give instructions for smooth running of the factory. It is separated from the rest of the factory working area.

Similarly, in cells, the nucleus is the instruction center, where instruction for protein synthesis (products) is coded. It is protected by a nuclear membrane ensuring its protection from the rest of the cell.

Tip: Link to microscope activity – In the slides of cheek and onion cells, you were able to see a clear dot/spot within the cell. This is the nucleus.

DNA/ Chromosomes It is the code/formula for making products or proteins. DNA is a long strand of material that is folded many times to make a structure called a chromosome. These chromosomes are found within the nucleus.

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35 Tip: Link to microscope activity – DNA/Chromosomes are found inside the nucleus but they are too small to see using our microscopes. Many times the chromosomes will get unfolded. Unfolding happens when the cell divides, or when a particular portion of the “formula” needs to be read. During cell division, the entire chromosome gets unfolded and if you find a dividing cell, one can see chromatin material using special colors or stains.

Mitochondrion It is the powerhouse of the cell providing energy for all cell activities. In a factory, it is the main electric station where electric current is supplied to different parts/stations of the factory.

Tip: Link to microscope activity – Depending on energy needs, different amounts of cells have different mitochondria. Take the wing muscle of an insect – flying is a very intensive activity and requires a lot of energy. If you view cells of insect flight muscles, you will be able to see bundles of mitochondria.

Endoplasmic Reticulum It is the production site. It is close by to the headquarters where products are produced. Products are modified or polished before release. It has ribosomes (like workers) on the surface responsible for synthesizing and assembling the proteins. It has continuous connections with the nuclear membrane.

Tip: Link to microscope activity – Endoplasmic reticulum are very tiny structures and cannot be viewed with light microscopes. They can be viewed through a special type of microscope called electron microscopes that has the power to magnify objects much, much more than light microscope.

Chloroplast Some factories are able to make all the products using very basic raw material. Other factories buy preprocessed material and do additional work on them. Plant cells are examples of factories that make all products using very basic raw material. They use sunlight and carbon dioxide to make basic sugars. In such kinds of factories/plant cells, chloroplasts form an additional production center like a kitchen. In animal cells (such as ourselves), we eat plants to get their sugars (pre-processed material). As a result, we don’t have chloroplasts.

Tip: Link to microscope activity – Chloroplasts can be found in all green parts of plants. They contain the pigment that makes leaves green. Chloroplasts help plants trap sunlight and make their own food. If you were to inspect a leaf of hydrilla, you will see lots and lots of small green dots in a cell. These are the chloroplasts. Animals do not contain chloroplasts and are unable to trap sunlight and make their own food.

Golgi Apparatus (Pronounced Gol-jee ) It is the sorting center of the cell. Compare this to the sorting center in post offices, where letters have addresses, stamps, pin-codes that mark the location to which it has to go. The Golgi apparatus is where proteins are tagged with “addresses” and sent off to the correct postman or delivery person.

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36 Link to microscope activity – Like endoplasmic reticulum, Golgi bodies too are very tiny structures and cannot be viewed with light microscopes. They can be viewed through a special type of microscope called electron microscopes that has the power to magnify object much, much more than light microscope.

Vesicles (Pronounced věs'ĭ-kəl) Vesicles are like the postman or delivery person. Sometimes vesicles transport proteins within the cell.

Other times, they take proteins outside the cell. Other times, they may transport material from the outside to inside the cell.

Tip: Link to microscope activity – Again, like endoplasmic reticulum and Golgi bodies, vesicles can be seen only through an electron microscope.

Lysosome In any factory, not all material is used up. Some waste is generated while making the products. Sometimes, an incorrectly produced product will need to be disposed. The lysosome is like the cell’s disposal machine – it is here waste material is incinerated (burnt), destroyed or efficiently degraded.

Tip: Link to microscope activity – Again, like endoplasmic reticulum and Golgi bodies, and vesicles, lysosomes can be seen only through an electron microscope.

Vacuole The vacuole is like a storage space of the cell. Sometimes we store junk and waste material in the storage space. Sometimes we store raw material that we might need later. Vacuoles in plant cells are often larger than those in animal cells.

Tip: Link to microscope activity – Did you notice that that nucleus in the onion peel cell was in a corner but the nucleus in the cheek cell was in the middle. This is because a large vacuole is present in most plant cells, pushing the cytoplasm, all the organelles and nucleus to a corner. Plant cells have large vacuoles. Unlike plant cells, animal cells have small vacuoles, so the space occupied by the cytoplasm and everything else is quite large Summarize Just like how we had to wait for the invention of compound microscopes to realize that all living matter was made of cells, we had to wait until electron microscopes were invented to see what was happening inside a cell!

Remember how we blew a bubble in the beginning of the class? A cell is actually like a ball of cytoplasm in which organelles float. They are held together by a cell membrane. If you sliced open the ball, we would be able to look at all the departments (or organelles). If we sliced open the cell, it would look like the clay models all of you have assembled. But an intact cell would be like a big ball and we’d only be able to the cell membrane (or cell wall for plants) from the outside.

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SESSION 3.2e Link to known information/ previous activity Not Applicable Procedure Display plant and animal cell charts on the boards.

Ask learners to compare their chart with others chart and spot the differences between plant and animals cells.

UNDERSTANDING THE ACTIVITY 3.2e Leading questions What are the differences you notice between the two types of cells?

Discussion and Explanation Discussion Item 1: Plant cells and animal cells are similar in many ways, but there are a few differences. Plant cells have  Cell walls  Chloroplasts  Large vacuoles These are absent in animal cells.

KEY MESSAGES   

Cells work like a factory.

Cells contain organelles, each of which performs a specific function.

Compared to animal cells, plant cells have cell walls, chloroplasts and a large vacuole.

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38

LEARNING CHECK Distribute learning check worksheet to assess students on ABL 3. Key is provided here for your reference.

1. All living things are made up of

2. The inside of a cell is

.

and jelly-like.

3. A cell can be considered as the

part of an organism that can survive on its

own.

4. All cells have a

5. All cells are

, which separates them from the outside world.

the same.

6. Some organisms consist of only

7. More complex

cell, like amoeba, or bacteria.

, are made up of lots of different types of cells.

8. Plant cells have a group of green structures called

. They use the energy from

the Sun to make food.

9. The mitochondria are often called the

of the cell.

10. Cell walls are present in plant cells, true or false?

1:Cells,2:Cytoplasm,3:Living,4:Membrane,5:Not,6:Single,7:Organisms,8:Chloroplasts,9:Powerhouse,10:Tru e.

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TRY IT YOURSELF A) Make a model of a plant and animal cell using common materials found at home like thermocol, beads, beans, strings, sticks, jelly, etc.

Figure 2: Model of Plant Cells

INTERESTING INFORMATION    

Nerve cells have to connect from brain or spinal chord in our back to our legs Some of our nerve cells can be up to 1.5 meters long The nerve cells of the giant squid can be 12 m long (but very thin) However the biggest cell (by volume)is an algae caulerpa (3 meters tall)

WEB RESOURCES http://www.iknowthat.com/com/App?File=ScienceLab.htm&Type=S&SWF=cell%2Fscience_desk&App=Sci ence+Lab&Topic=Cells http://www.columbia.edu/~mvh7/STEP/Regents%20Bio/Cells/notes/cells%20vocabulary.pdf

REFERENCES Figure 10: http://farm6.staticflickr.com/5265/5690516135_1ee28f6295.jpg Figure 11: http://commons.wikimedia.org/wiki/File:Microphoto-cells-onion2.jpg http://www.columbia.edu/~mvh7/STEP/Regents%20Bio/Cells/notes/cells%20vocabulary.pdf http://www.quia.com/quiz/286672.html?AP_rand=1255086104 Figure 14: http://science9ipp.blogspot.in/ http://www.biologycorner.com/resources/plant_cell.gif http://1.bp.blogspot.com/-k4dIs9AilNc/TnvYzDu7mI/AAAAAAAAAO4/dUU2pJX3puU/s1600/cell+as+a+factory.jpg

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APPENDIX ABL 1.2: Observation Sheet Name of student: Class/Grade: School: Specimen Image with naked eye

Image with magnifying glass

Image through microscope

Tissue paper

Onion cell

Cheek cells

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41

ABL 2.2: Observation Sheet Name of student: Class: School:

2.2a Width of coin in front of

Width of coin behind glass

glass

2.2b Image as seen with naked eye

Image through magnifying lens

5 rupee coin

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42

ABL 3.1: Observation Sheet Name of student Class School Group name Image through microscope

Amoeba

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43

ABL1 3: Placard and Chart Material Placard & chart material for ABL 3

http://1.bp.blogspot.com/-k4dIs9AilNc/TnvYzDu7mI/AAAAAAAAAO4/dUU2pJX3puU/s1600/cell+as+a+factory.jpg

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44 Placard set

N

Part

Function

Nucleus

Leader of boss

How does it look

url

o 1

http://iws.colli n.edu/biopage /faculty/mccul loch/1406/outl ines/chapter% 207/animalcell 2.jpg

2

DNA/

Formula of

http://www.e

Chromosomes

the product

urogentest.org /blocks/leaflet s/images/engli sh/dna_chrom osomes_genes .png

3

Mitochondria

Power

http://fusionano maly.net/mitocho ndria.html

house

4

Endoplasmic

Assembly

http://www.vi

Reticulum

line/productio

sualphotos.co

n site

m/photo/1x84 66882/endopl asmic_reticulu m_tem_9C478 5.jpg

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45 Ribosomes

Workers

http://www.cytoc hemistry.net/cellbiology/rer2.jpg

5

Chloroplast

Kitchen/ Food

http://biology-

production

pictures.blogspot. in/2011/10/chlor oplast-in-plantcell.html

6

Golgi Apparatus

Sorting center

http://bio1151.ni cerweb.com/Lock ed/media/ch06/0 6_13GolgiAppara tus.jpg

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46 7

Vesicles

Transport

http://medcell.m ed.yale.edu/syste ms_cell_biology/

ers

bloodvessels/ima ges/plasmalemm al_vesicles.jpg

8

Cell membrane

Wall /

http://am.celllibr

Boundary

ary.org/ascb_il/re nder_image/1000 4/0/0/?c=1|0:255 $FF0000&m=g&p =normal&ia=0&z m=100&x=0&y=0

Cell Wall 9

Lysosome

Incinerator/

http://synapses.cl

Waste

m.utexas.edu/lab

disposal

/howto/protocols /Endosomes/ima ges/image22.jpg

1

Cytoplasm

Working space

0

http://www.davi ddarling.info/ima ges/cytoplasm.jp g

1

Vacuole

Storage space

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47

PLANT CELL - http://www.biologycorner.com/resources/plant_cell.gif

ANIMAL CELLhttp://www.enchantedlearning.com/subjects/animals/cell/anatomy.GIF

Agastya International Foundation . For Internal Circulation only.

Request to Readers- Kindly mail details of any discrepancies to handbooks.agastya@gmail.com