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DISSECTING FROG ANALYSIS PROCESS BY: ASTA YOUNG

INTRODUCTION: Throughout the Biology course, there were numerous amounts of great ideas waiting to be discovered. Nikki and I have decided to work on a biology experiment, where we would be dissecting frogs. Our goal for this experiment is to successfully dissect two frogs in order to compare the organs, and see if the size of the frogs would create any differences in the organs. This plan wasn’t as successful, thus Nikki and I, decided to use one frog and take skin and blood cells from it. Then comparing the cells we got from the frog, with human cells. During this experiment, the independent variable is the frog cells and human cells. The dependent variable is the differences between the frog cells and the human cells. At first when we tried to compare the organs to see the differences in the organ size, our expectations were that the smaller the frog, the smaller the organs. My general expectation for our second try on the experiment is that the frog blood and cells would definitely differ from our human cells. The frog dissection could relate to the real world in numerous ways. For example, what if suddenly a disease struck among the frogs? Scientists could dissect a frog, and see if anything was wrong. Not only that, they could take blood samples and compare it to other living things. Another way it could relate to the real world is for students to understand what goes on in our body. Since a frog’s organ structure is very likely quite similar to us human beings.

MATERIALS:

 2x People (Nikki and I)  2x Pairs of Gloves  2x Lab Aprons  2x Dissection trays  2x Safely Goggles  8x Dissecting Pins  Paper Towels  2x Storage Bags  2x Disposable Bags (when disposing the frogs)  1x Scissors  1x Microscope in order to analyze  1x Camera to take photos  1x Computer  1x Supervisor  2x hairdryers  1x Freezer  1x Suction Droplet  1x Needle METHOD AND PROCEDURE:

 DIAGRAM

 PROCEDURE FOR THE ORIGINAL EXPERIMENT(Comparing size)

1) Look up procedures and ONLINE FROG DISSECTION within www.google.com. A recommended site would be www.froguts.com.

WHY? This way you can understand how to dissect a frog more, with actual images and a step by step process.

2) Head to Carrefour and do the following:

 Find 2 Frogs, preferably Carrefour. This is because; the frogs in SAS are too small to work as an experiment.

CAUTION: When in Carrefour, please tell the store keeper to kill the frog before putting it in a bag. This is because from experience, the frogs jumped out of the bag and had involved multiple security guards.

 Place the frogs in bags. If not dead: Tie the bag tightly. WARNING: If alive, please warn the cashier lady or else she will freak out.

 Find some boxes in order to put the frogs in (if the frog is not dead)

3) Place the frogs in the freezer IMMEDIATELY, or risk the frog jumping out if not dead. If the frog is dead, then that should be simple, also place in the freezer.

4) Take the frogs out of the freezer at least an hour before dissection time

5) If still a bit frozen, use the blow dryers to blow dry them

6) BEGIN DISSECTION:

WARNING:

Safety gloves are a must, or risk getting diseases or getting cut by the tools.

 Place the First Frog in the Pan:

Rinse the frog with water then place it in the dissection pan. Place the frog on its back, with its belly facing upwards.

 Pinning: Use the pins to pin each leg down on to the dissection pan.  First Incision: Use forceps to lift the skin midway between the rear legs of the frog Use the scalpel to make a small cut through the lifted skin (should be made along the center)

 Continue Skin Incision Now, using the scissors, continue the incision up the midline all of the way to the frog's neck. Be very careful not to cut too deeply.

 Finish the First Skin Incision When your scissors reach the frog's neck, you have cut far enough.

 Cut above Front Legs

Using either the scissors or the scalpel, make horizontal incisions through the skin between the front legs

7) Explore the interior of the frog. For example: - explore the organs

8) Do the same process with the second frog

9) Look for the similarities between the big frog and the small frog

 PROCEDURE FOR THE NEW EXPERIMENT (Frog + Human Cells)

1) Take the frog out of the freezer at least an hour before dissection time

2) Blow dry the frog if still frozen

3) Repeat dissection process shown in the earlier experiment

4) Use the scissors and cut a piece of skin off the frog and place it on a slide 5) Use the Suction Droplet thing to suck up some leftover blood from the frog, then squeeze a drop onto a slide

CAUTION:

Label the slides or else you will mix up the frog and the human blood

6) Use a needle and prick someone’s finger in order to get human blood, use the suction droplet to suck up the blood. Then squeeze onto a slide

7) Find some dead skin cells from someone (in our experiment, Marjolein kindly donated her skin)

REMINDER: All these are used under 2.5x10 Magnification

8) Place the frog skin under the microscope then observe (use the camera to then take a picture of the frog skin through the lens) Refer to Diagram A

9) Place the human skin under the microscope then observe (use the camera to then take a picture of the human skin through the lens) Refer to Diagram B

10) Place the frog blood under the microscope then observe (use the camera to then take a picture of the blood cells through the lens) Refer to Diagram C

11) Place the human blood under the microscope then observe (use the camera to then take a picture of the blood cells through the lens) Refer to Diagram D

12)Compare and Contrast the pictures for example:

- Frog Skin to Human Skin - Frog blood to Human Blood EXPECTATIONS:

The first experiment we tried, we had numerous expectations:  The smaller the frog, the smaller the organs  The bigger the frog, the bigger the organs We didn’t really have a lot of expectations for the first experiment, since it was too plain and not narrow enough.

The second experiment we tried, we had numerous expectations:  Our blood cells would differ a lot with the frog blood cells in color, the size, and the shape. But, the basic structure would be similar for example- the nuclei, nucleus, and etc.  Our Skin cells would also differ a lot. The frog skin cells would probably be a lot more rough and would have some patterns on the skin. While the human skin would be smooth. Both would probably have the nuclei shown.

General Expectations- We expected to be able to clearly see the cells, and be able to identify them

RESULTS: There were many results in our experiment. During our first one with the organs, it didn’t really work. Since we didn’t take a lot of pictures, we didn’t have anything to work with. Our result was, the frog had a lot of organs similar to ours. They have all the systems, and you can clearly identify them. Here are some pictures during the dissection: The second experiment was a lot better, and we had pictures for our results.

 FROG SKIN (DIAGRAM A)

The top left is an outer view of the frog skin. The ones underneath and beside it are the views of the skin through a microscope. The one beneath the outer view is the rough part of the skin. The rest are the soft parts of the skin.

 HUMAN SKIN (DIAGRAM B)

The picture to the left is the human skin from Marjolein. This was taken under the microscope.  FROG BLOOD (DIAGRAM C)

This was the only image we could get of the frog blood. It was really hard to find the frog blood. We think that the frog blood was probably interfered with when the frogs were frozen.

 HUMAN BLOOD (DIAGRAM D)

These are diagrams of Asta’s blood cells. People wondered why it was a strange color. The top was a zoom in on the blood, while the bottom was the outer view. ANALYSIS:

Throughout our results we found many interesting facts. First off we’ll start off with the skin cells. In the frog skin cells (refer to Diagram A) it was mainly rough, with a slight green color towards it. In the human skin cells (refer to Diagram B) it was mainly smooth, with a slight view of the nuclei. It seems that human skin is easier to notice the nuclei then the frog cells.

Within the blood cells, we found quite interesting facts. We noticed that the frog blood (refer to Diagram C) is quite hard to find. That picture is the closest we got to. When compared with the human blood (refer to Diagram D), you can clearly see that the human blood is more noticeable. Not only that, but the human blood is more clear, and has a better view. I decided to look up frog blood on the internet and compare it with my results.

This is an internet version of the frog blood. Our version was completely different, but if you compare it to the human blood, you can see some differences. The frog blood is more oval, and a lot wider. Meanwhile, the human blood is more circular, and smaller.

DISCUSSION:

Throughout this investigation, I found out a lot more about Biology and the frog anatomy. I also found some things about myself as well.

MYSELF- During this investigation, I found out that I formed a large fear of frogs. This was probably because of the supermarket incident, where the frogs jumped out of the bag.

FROG ORGANS- During this, we noticed some things that we never knew before. I noticed that all of the organs were connected to each other, so that it was really hard to take apart each organ. Not only that, but we also noticed some other things. In female frogs, they usually have eggs and ovaries in them. Not only that, but female frogs tend to have slightly bigger organs then the male frogs. This was a shock to us both, since we always thought the male frog would have bigger organs. Not only that, we also noticed that frogs have a large amount of fat bodies, and etc. The main thing I learned was the organs. I never really got to learn the organs really well in human beings, which explain why I thought the stomach was a kidney. During this experiment, I got to learn the organs really well and can name them as well. I felt like that was a huge achievement for me.

COMPARING FROG BLOOD WITH HUMAN BLOOD-

This part, I learned that the frog blood can easily be messed with. If you freeze a frog, it could damage the blood which in our case, didn’t help our experiment. It was hard to find the frog blood, due to the freezing problem. From help from google images, I found a picture of the frog blood. Generally our blood (refer to diagram D) is much more rounder and a lot more detailed and smaller. While the frog blood (refer to internet diagram above) is a lot bigger, and in an oval shape.

COMPARING FROG SKIN WITH HUMAN SKIN-

This part, I learned that frog skin have different textures. Frog skin can be rough, and it can also be smooth. Not only that, but frog skin usually are green. While the human skin was different, I learned that human skin is a lot more detailed. In DIAGRAM B, you can see the nuclei within the skin cells. Compare that with Diagram A, which was the frog skin. The frog skin doesn’t show as much detail as the human skin.

If I were to change the experiment, I would first go back to Carrefour, and ask the lady to kill the frogs. This way, we won’t have to freeze it, and we might get a better view of the blood. Not only that, I would probably take skin cells from the frog in different areas. What if different areas of the frog have different textures?

APPENDIX I:  Frogs: Any of numerous tailless, aquatic, semiaquatic, or terrestrial amphibians of the order Anura and especially of the family Ranidae, characteristically having a smooth moist skin, webbed feet, and long hind legs adapted for leaping.  Dissection: Cutting/separating something into pieces for detailed critical analysis  Digestive system: the system that makes food absorbable into the body  Circulatory System: The system that circulates blood through the body, consisting of the heart and blood vessels.  Skin: the external covering or integument of an animal body, esp. when soft and flexible  Blood: the fluid (red in vertebrates) that is pumped through the body by the heart and contains plasma, blood cells, and platelets  Cells: The basic unit of living matter in all organisms  Gall Bladder: a pear-shaped, muscular sac attached to the undersurface of the right lobe of the liver, in which bile is stored and concentrated.  Heart: The chambered muscular organ in vertebrates that pumps blood received from the veins into the arteries, thereby maintaining the flow of blood through the entire circulatory system  Stomach: a saclike enlargement of the alimentary canal, as in humans and certain animals, forming an organ for storing, diluting, and digesting food.  Bladder: a membranous sac or organ serving as a receptacle for a fluid or air  Kidney: either of a pair of bean-shaped organs in the back part of the abdominal cavity that form and excrete urine, regulate fluid and electrolyte balance, and act as endocrine glands  Small Intestine: The narrow, winding, upper part of the intestine where digestion is completed and nutrients are absorbed by the blood. It extends from the pylorus to the cecum and consists of the duodenum, the jejunum, and the ileum.  Large Intestine: The portion of the intestine that extends from the ileum to the anus, forming an arch around the convolutions of the small intestine and including the cecum, colon, rectum, and anal canal  Liver: a large, reddish-brown, glandular organ located in the upper right side of the abdominal cavity, divided by fissures into five lobes and functioning in the secretion of bile and various metabolic processes.  Ovaries: the female gonad or reproductive gland, in which the ova and the hormones that regulate female secondary sex characteristics develop  Lungs: two spongy, saclike respiratory organs in most vertebrates, occupying the chest cavity together with the heart and functioning to remove carbon dioxide from the blood and provide it with oxygen.  Microscope: an optical instrument having a magnifying lens or a combination of lenses for inspecting objects too small to be seen or too small to be seen distinctly and in detail by the unaided eye. APPENDIX II:

The big idea of our experiment was Dissection. Dissection can be helpful in numerous ways. One of the biggest help is to help us have a better understanding and comprehend the workings of the body. Not only that, it could help us see how organisms can be different through the blood, skin, and organs. For example, from dissection you can see what each organ looks like and have a better understanding on how one affects each other. Within the diagram, you can see the labeled diagram of the organs within a frog. Not only is dissection a big idea, but blood cells and skin cells are big ideas as well. Blood and skin cells, could help us understand the differences and similarities between different living organisms. For example, we looked at frog blood and skin cells, and we found numerous differences between frogs and humans. Another example is, let’s say we want to compare dog blood with fish blood. Here are some example pictures:

Here are the blood cells of a dog: Here are the blood cells of a fish:

Just with simply the blood cells, you can easily identify differences through different organisms. For example, dog cells are much clearer and bunched up. While fish cells are spread out and are darker.

REFERENCES: www.google.com www.froguts.com http://faculty.clintoncc.suny.edu/faculty/Michael.Gregory/files/Bio%20102/Bio %20102%20lectures/Animal%20cells%20and%20tissues/Animal%20Tissues.htm http://www.cambridge- hitachi.com/products/secondary/bioscope/downloads/zoological/frog_blood.pdf biology/frog/resp.htm**|**www.aa.psu.edu/ biology/frog/resp.htm** http://www.biologycorner.com/worksheets/frog-dissection.html

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