Frog Dissection Lab

In the frog dissection lab, we cut open a preserved frog and examined organs inside it. It may have been a little gross, but it was very fascinating! Even though a frog may not seem like it is anything like a human, our organs are very similar. The main differences, in my opinion, are their location and their appearance. But that may just be because of proportions.However, this is not what we noticed right away. Our first direction was to identify whether it was a male or a female. We opened it and saw no eggs. It was concluded that the frog was a male after the testes were located. Then, we saw these small noodle-shaped structures attached to the body. These were the fat bodies. Because there were so many of these, it took awhile to take them out. Sadly, we accidently ripped out the testes when we wer dissecting. Even though these organs were small and hard to find, there were some organs that you can't miss by sight. The biggest was the liver. It was made up of three big lobes and seemed to take up alot of the space inside of a frog. It also hinders the examination of the other organs. After taking out the liver, you could see so many more organs. One organ that stuck out to me was the gallbladder. It looks like a small green bubble. It is located directly under the liver. Also, I was humored by the appearance of the heart. It actually somewhat looked like a cartoon heart! But it was a little more triangle-shaped than a cartoon heart. Also, the small instestine looked really cool when you removed it and stretched it out. It was so long! All of these organs are in our bodies also. So, when you look inside a frog, it isn't too hard to locate all of the organs. It was so amazing to be able to touch and examine each organ and remove it from the frog. Oddly, it was gross at the same time! We saw organs like the spleen, kidney, lungs, and pancreas. I would definitely do it again. But if I did do it again, I would hope that it doesn't smell as bad as the first time! For more information on frogs, you can go to these websites:
Here is an online dissection game:
http://www.surgery-games.org/43/Dissect-a-Frog.html
Note: This game is online dissection in which you then have to identify the individual parts.
For further knowledge about frogs, visit this website:
http://www.e-tutor.com/et3/lessons/view/52133/print         
Diagram of the internal structure of a frog:
 

Chicken Wing Dissection

Recently, my science class dissected a chicken wing to study the different types of tissue in organisms. Though we may seem like completely different species, we all have the same basic tissues in our arms. For example, we both have biceps and triceps, the muscles that control the movement of the arm, or wing. Also, we both have skin, tendons, ligaments, and nerves. In addition, when all of these tissues had been removed, you can see that both the chicken and and the human have an ulna, radius, and humerus. These are the bones of the arm. I know some people might have thought this was disgusting, but it is the food we consume in our bodies and I found the dissection quite helpful in learning about our bodies. This is because our build and a chicken's build are quite similar to each other.

Diffusion Lab Report

The diffusion lab created an understanding of the processes inside a cell using iodine, cornstarch and water. The purpose of the lab was to observe the diffusion of a substance across a semi permeable membrane.  To do this, iodine was used as the indicator and a plastic baggie was used as the permeable membrane that separated it from the substance it indicated which in this case was starch. Since iodine is an indicator for starch, the predicted outcome was that when osmosis, a specified form of diffusion with water, occurred and the iodine moved across the membrane, it would change color in the presence of starch.  Initially, the iodine was hypertonic since it was highly concentrated in the beaker. As it moves across the permeable membrane, it would be diluted to a lower concentration by the water and became hypotonic. It was predicted that the iodine would diffuse across the permeable membrane so that the concentration of iodine in both the baggie and the beaker would be the same and thus isotonic.

After 15 minutes of observation, the solution in the baggie changed from white to a shade of purple while the solution in the beaker remained orange. This leads to the conclusion that the iodine diffused through the baggie and underwent the process of osmosis, as predicted, to indicate the starch by changing its color. Since the contents of the beaker remained unchanged, it was apparent that the semi permeable membrane did not allow the starch to transfer from the baggie to the beaker thus the baggie was selectively permeable. The occurrences in this lab mimic the behavior of the cell membrane. The cell membrane is what protects the cell and selectively controls the movement of molecules into and out of the cell. Thus, it is selectively permeable just as the baggie was selective with the iodine and the starch.  This is how cell membranes react with water and food molecules. Certain molecules can pass through the cell membrane to benefit the cell whereas harmful molecules are blocked from entering the cell. This process is required for the cell to function.

Looking outside of this experiment, diffusion is utilized on a daily basis by most people. For example, when a tea bag is placed in boiling water, the molecules of the tea leaves diffuse through the tea bag to color and flavor the water. Another situation where molecules are diffused by osmosis is sugar and coffee. When sugar is dissolved in coffee, the sugar molecules spread throughout the coffee and sweeten its taste. Not all diffusion is beneficial. In the case of cigarette smoke, it diffuses into the air and causes second hand smoke inhalation. Also, car and truck emissions of carbon monoxide can be deadly when diffused in high concentrations. That is why the automobile engines cannot be started inside a closed area such as a garage. These examples show how diffusion has both a positive and negative effect on the human population.

Diffusion Lab: Response

Today, in science class, we did a diffusion lab experiment with iodine and starch. What we did was put about a teaspoon of cornstarch into a baggie and added 100 mL of water. We then filled a beaker halfway with water and our teacher added some iodine into it. After placing the baggie into the bveaker and letting it sit for about fifteen minutes, we observed what we saw. And of course, what we saw supported what we learned about diffusion, the movement of molecules from a higher concentrate to a lower concentrate. We also related it to what we know about cells and how a cell membrane could be selectively permeable, or able to choose what goes into and out of the cell. Also, we learned that iodine as in indicator of cornstarch. An indicator is a substance that changes the color of another solution when coming in contact with each other. In this lab, the indicator was the iodine and it seeped through the bag and turned the cornstarch a hue of purple. This lab experiment was one that was just a remarkable sight in seeing the colors change. Also, connecting cells that we have studied to our studies in the lab really helped me understand all of these processes and definitions that sound so confusing. Hopefully, we will do many more labs this year!

Class Response

In science class, we have been working with cars. these cars are gravity powered vehicles that we built our selves. Even though building a car can be hard, it's worth it in the end. The funniest part of working with these vehicles was when everybody brought their cars in and presented them. That's because of course, every person is unique so every car is unique. Some cars were small, and some were big. There were a few that looked like ordinary cars, and others were abstract. When I say abstract, I mean that they looked absolutely nothing like real cars. except for the fact that they had wheel. You could find cars made out of water bottles, soda cans, and shoe boxes. There were also very odd wheels. A lot of people made them out of C.Ds and other people made them out of cardboard and paper. Other people found old plastic wheels or little junk items they found around their houses to construct wheels. After all the cars were turned in, we started running them down the ramps that were built. I enjoyed watching them go down. Some of them didn't even get down the ramp! Other cars went to the very end of the classroom. My car got off the ramp, but it didn't go very far. But still, it was fun to laugh at my own creation! Oh, I forgot to mention why we were even using cars in the first place! Well, we were learning about motion, forces, and many other things in our physics unit, and we used cars to help us learn about them. I never realized how interesting physics can be until now!

Science Blog 5/17: Are coffee drinkers less prone to aggressive breast cancer?

http://health.yahoo.net/news/s/hsn/arecoffeedrinkerslesspronetoaggressivebreastcancer

 I believe that this breakthrough in the medical field just give scientists and doctors some assistance in finding a solid cure for breast cancer, a common disease among women. At first, scientists had very few leads as to what might prevent or reduce the odds of being diagnosed with breast cancer. Then all of a sudden, a group of Swedish researchers discover that a particular ingredient in coffee can make you less prone to aggressive breast cancer. It is not a cure, but it is a step closer to finding the cure to a serious health issue for women around the world. Perhaps the key is to manipulate some of the ingredients in coffee to utilize the component that reduces the risk for breast cancer and proceed from there. I know I am certainly no scientist of any kind but if it were me in the lab and working towards finding the cure for breast cancer, that is what I would do. Obviously, breast cancer is a serious dilemma that requires a method of prevention or a definite cure. For all we know, this breakthrough may be the key component to finding a cure or method of prevention for this hurrendous disease.

Blog 4: Growing Artificial Meat in Labs to End Hunger

http://www.foxnews.com/scitech/2011/01/31/growing-meat-labs-end-hunger/

     Recently, scientists have developed the idea that "cultured"(artificial) meat will end our world's hunger and also be much less expensive. In other words, they have been creating genetically engineered meat that apparently can be designed to your liking. Scientists say that they "envision football field-sized buildings filled with large bioreactors, or bioreactors the size of a coffee machine in grocery stores, to manufacture what they call "charlem" -- "Charleston engineered meat.". In my opinion, the idea of growing meat in a lab is unethical. I mean, its obviously unnatural, especially because you don't know how it is grown. It might have chemicals, or other toxins and ingredient that just aren't healthy. Also, isn't meat supposed to contain proteins that our bodies need to survive? I understand that it could possibly solve some of our world's large economic crises. But is it really worth all the risks? Some people may not agree, though I'm sure the idea of genetically engineered meat is both unethical and at too high of a risk. I mean, think about this, who would want to eat artificial meat?

Blog 3: Class Response

I found today's science class very intriguing, although very confusing. Someone came in and informed us on his work in Egypt's Valley of the Kings and how to date fossils and rocks. The Stratigraphic Laws are the ways you use to give rocks a relative age. These include horizontality, superposition, intrusions or faults, and inclusions. Each one of these is a different law you can use to date rock. You can also do this with layers of rocks, just like the examples we did in class. In addition to giving rocks a relative age, you can also give a fossil a relative age based on what layer of the rock it is found in. We use all of this today to determine what Earth was like millions of years ago. I found all the things we did in class quite fascinating. Paleontology and geology are very unique fields to work in.