1.0 Abstract

Aim of this experiment is to identify structure of plant cell and animal cell and to distinguish

between the two. This experiment was conducted to meet that purpose. Both plant cell and

animal cell belongs to the big family of eukaryotic cell but that doesn’t mean that both have

the same structure and characteristics. Methodology used in this experiment includes use a

proper staining method and practicing a better microscope skill. By doing a proper staining

method is to have a better view on the cell. Before conducting the experiment one should

know how to handle a microscope and make sure to know what type of microscope to use. I

think in the study of microbiology we should know how to handle a microscope correctly. It

is the most basic skills that someone should have in the microbiology field. Follow a proper

step in handling microscope and after used the microscope should be keep in proper way.

This experiment seems simple but it carries a big impact. Cell is a basic unit of life so by able

to identify this cells and how it works, one should be able to find a way for virus and illness

counteract, thus creating medicine and a way to cure it. We know that every part of our body

started with a single cell that multiply and later carried out specific function. Every cell is

unique and it has own composition and undergoes specific reaction. Some cell lack of certain

organelles because of the reaction it carried out. This experiment also show to identify a basic

structure of cell that every cell should have.

Moreover, by knowing the structure of the cell we can also identify on the composition that

make up the structure of that particular cell. Certain compositions give out certain function to

the cell. For example, cellulose gives plant cell a rigid structure so that it can sustain osmotic

pressure of the cell. In conclusion knowing a cell is like knowing yourself as you are make

from a single cell that duplicate to become multi-function organism.

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2.0 Introduction

Cell is a basic unit of life. Every organisms start with a single cell that develop to become

multi-function organism. Cells can be divided into two that is prokaryotic and eukaryotic.

Cell consists of basic features such as plasma membranes, semifluid substances (cytosol),

chromosomes and ribosomes. Animal cell and plant cell fall into the category of eukaryote.

This experiment had been conducted to identify the composition of animal cell and plant cell

and also to distinguish between the two.

Microscope is used to identify the cell structure and it composition. Different magnifications

are used to take clearer view on the cell. Onion cell are the sample used to identify plant cell

and chicken cell for animal cell. Safranin is used for staining in this experiment. Safranin is

red dye that will colour the nucleus of the cell red.

3.0 Objective

The objective of this experiment is to

3.1. Observe the structure of plant cell and animal cell.

3.2. Distinguish the differences between animal cell and plant cell.

3.3 Learn a correct way to handle microscope and to be able to practice a correct way

of doing staining procedure.

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4.0 Theory

Microscope is a tool that can make humans able to see things beyond our eye ability such as

small microorganism. Every microscope should have these two characteristics such as

magnification, the ability to make object appear enlarge and resolving power, the ability to

show detail. Theory of refraction is used in microscope when a beam or ray of light

transmitted through air strikes and passes through the convex surface of glass. The power of

magnification depends on the size and curvature of the lens, image appears enlarge to a

particular degree.

In preparing for specimen there is three condition that we should take care first is the

condition of the specimen, either it is in living or preserved state. Secondly is aim of the

examiner whether to observe overall structure, identify microorganism or to see the

movement. Lastly, types of microscopy available such as bright-field, dark-field, phase-

contrast or fluorescence. In this experiment, we used wet mounts to maintain viability

temporarily and provide spaces and medium. The simplest wet mounts we can do are adding

a drop or two on the specimen and overlaid with a cover glass. Although this type can’t

sustain for a long period and only be able for a short period of times. For a longer period of

specimen we can use a drop of Vaseline adhesive or sealant.

As for the stain we used positive staining concept. Positive staining concept works in a way

that the dyes stick to the cell and give them colour. In this experiment we use safranin that

gives the cell red colour. This simple staining cause all cell to appear more or less the same

colour regardless of type but can reveal characteristics of specimen.

Cell is basic unit of all complex organisms we know today. Cell can be divided into two

categories eukaryote and prokaryote. Eukaryotic cell are much complex than prokaryotic cell.

Example of eukaryotic cell family is animal cell and plant cell.

Plant cell structure can be divided into plasma membrane and cell wall; and organelles.

Organelles of the cell are made up of nucleus, endoplasmic reticulum, ribosomes,

mitochondria, chloroplast, vacuoles, and Golgi complex. Nucleus acts in controlling genetic

material of the cell. Nucleus structures are made up of nuclear envelope, nucleolus and

chromatids. Cell wall is involve in giving the plant cell rigid structure and fixed shape while

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cell membranes consist of phospholipids bilayer that controls the activity and movement of

substances into and out of the cell.

Animal cell structure consists of plasma membrane that act a control barrier that control and

regulates the movement of substance through the cell and also organelles. In animal cell the

organelles consist of nucleus, endoplasmic reticulum, ribosomes, mitochondria, vacuoles and

Golgi complex. Animal cell lacks cell wall and chloroplast meanwhile the vacuole is smaller

than one in plant cell.

5.0 Procedures

Part 1: identify animal cell

1) The glass slide is cleaned using distilled water and let dry.

2) Next, gently scraped the skin of the chicken using sterilized cotton swap. The

scraping was being done at least ten times on the chicken skin to make sure that the

cell was collected from the source.

3) The cell then was placed to the glass slide.

4) One drop of water was added to the chicken cell to create wet mounts.

5) Then, coverslip was being put to the glass slide starting from the one edge gently.

6) Tap the slide gently to remove bubble.

7) A few drops of safranin are placed at one edge of the cover slip. Another opposite

edge of cover slip was touched using a paper towel to draw the strain under the slip.

8) The slide is then was placed under microscope stage started with low magnification

and the results was being recorded. The magnification are set higher and then

recorded.

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Part 2: identifying plant cell

1) A small section of onion skin was peeled off as thin as possible using forceps.

2) The onion skin was placed in the centre of the slide.

3) Two drop of distilled water are placed to the onion skin to create wet mount.

4) From one edge we can gently lowered a coverslip over the onion skin.

5) Gently the cover slide was tapped to remove air bubble.

6) A drop of safranin was placed at one edge of cover slip and touched the other end of

the edge with paper towel to draw the strain under the slip.

7) The slide then placed on the stage under low power and recorded. Then increase the

magnification and record the data.

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6.0 Apparatus and materials

Name Function

Safranin solution A red dye that is used as staining.

Dropper Utensil used to transfer small quantities of

liquid.

Forceps An instrument used to hold small substance

in lab

Distilled water

Used to prepare wet mount on the specimen

cell.

Glass slide and coverslip

A small square of glass that cover the

specimen to be placed on microscope for a

better viewing.

Sterilised cotton swap

A tool used to transfer specimen from its

sources and spread it to the plate.

Onion

A source to get the specimen of plant cell for

observation.

Paper towel

Used to absorb excess liquid that is used as

staining.

Microscope

An instrument used to investigate small

substance in a study.

Table 6.1 shows name of apparatus and its function.

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Part 2: plant cell – onion cell

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8.0 Discussion

The hypothesis that I can make from this experiment is plant cell have a difference from

animal cell in term of structure and shape. From the experiment conducted I can conclude

that the hypothesis is accepted.

The results that I get from microscope viewing for plant cell in 10x magnifications I can

identify nucleus and cell wall structure. Meanwhile, for 40x magnifications I can identify

nucleolus, nuclear envelope, and cell well. For 100x magnifications results stay the same I

can still identify the same structure that is nucleolus, nuclear envelope and cell wall only for a

better magnification and larger view. The specimens are taken from the inner epidermis layer

part of the onion so the lack of chloroplast is justified. The inner epidermis layers of onion

also have a common elongated shape of onion cell.

Next, for animal cell for 10x magnifications I can identify nucleus, plasma membrane and

cytoplasm. Meanwhile for 40x magnifications I can identify structure as nucleolus, nuclear

envelope, cytoplasm and plasma membrane. As for plant cell same thing occur in animal cell,

in 100x magnification the identification is nucleolus, nuclear envelope, cytoplasm and plasma

membrane. Only 100x magnifications give a better close up view of the cell. Specimens of

animal cell are taken from the epidermis layer of the cell. This epidermis layers consist of

collagen, elastin and keratin.

This is due to the staining type that we used was simple staining and dye we used was

safranin. Safranin is a positive staining dye. Safranin give the red colour to the cell.

Regardless of the type of cell safranin give the same colour to the cell but we can see the

characteristics of the cell. Safranin is a simple dye that doesn’t show any specific organelles

in particular that’s why we are not able to identify organelles such as mitochondria,

endoplasmic reticulum or chloroplast.

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From this experiment, I can identify a few differences between animal cell and plant cell.

Plant cell appear to have a fixed, rigid and strong structure compare to animal cell that does

not have a fixed shape. Plant cell also has quite similar and neat arrangement in cell due to its

fixed shape. Next, are the presences of thick cell wall. Cell walls are rigid and provide

structural support as well as shape. Cell wall also acts as protective layer of the cell outside

the membrane. Cellulose is what that makeup the plant cell wall. There are three layers in cell

wall that is middle lamella, primary cell wall and plasma membrane. Middle lamella consists

of pectin while primary cell wall consist of cellulose microfibril and hemicellulose.

Although, there is also something that both cell have in common is that nucleus appear

clearly on both cell under microscope. Nucleus act as control centre of the cell. Nucleus

controls the activity of the cell. It is separated from the cytoplasm by nuclear envelope. There

are small pores in the nuclear envelope that act as a passage way of substance from nucleus

and cytoplasm.

9.0 Conclusion

From the experiment we can conclude that with 10x magnifications of animal cell with

safranin stain we can identify structure like plasma membrane, cytoplasm and nucleus. With

40x magnifications we can see plasma membrane, cytoplasm, nucleolus and nuclear

membrane. With 100x magnifications what we can identify is still nucleolus, nuclear

membrane, cytoplasm and plasma membrane.

As for plant cell with safranin as stain under 10x magnifications we can identify structure

such as cell wall and nucleus. Meanwhile, under 40x magnifications we can see cell wall,

nucleolus and nuclear envelope. Finally under 100x magnifications we can see cell wall,

nucleolus and nuclear envelope.

Safranin is a red dye that only able to colour the nucleus so other organelles are not able to

identify. To distinguish plant cell and animal cell is plant cell has rigid structure of cell wall

that gives it shape but not animal cell. In a nutshell, the objective are met I am able to identify

the structure of plant and animal cell, and I can also identify the differences in both cells.

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10.0 Recommendation

Based on the experiment we conducted the hypothesis are accepted and the objective was met

but there is several steps that I think can be taken to improve the experiment. Firstly, the

staining method should be done carefully to ensure that the safranin dye is spread evenly at

every part. The staining must not be too thick and too thin a correct amount of safranin

should add to the specimen. Secondly, gently remove the air bubble after placing the cover

slip. Next, the microscope should be handle more efficiently to ensure better view on the cell.

Lastly, handle the safranin carefully to avoid being spatter to cloth.

11.0 References

1) Kathleen Park Talaro (2008). Foundation in Microbiology. New York: McGraw-Hill

Companies.

2) Joanne M. Willey, Linda M. Sherwood, Christopher J. Woolverton (2008). Prescott,

Harley, and Klein’s microbiology. New York: McGraw-Hill Companies.

3) http://serc.carleton.edu

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12.0 Appendices

Figure 12.1 The microscopic view of plant cell under 40x magnifications.

Figure 12.2 The microscopic view of plant cell under 100x magnifications.

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Figure 12.3 The microscopic view of plant cell under 40x magnifications.

Figure 12.4 Handling microscope to identify cells structure.

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