Chicken Wing Dissection

In class, we watched our teacher perform a chicken wing dissection. This was to show how the human arm worked. As she was dissecting, the first type of tissue we saw was the skin tissue. The skin is a type of epithelial tissue. This tissue was whitish-yellow and was bumpy. The skin was attached to the muscle tissue. Then, our teacher showed us the muscle tissues. The muscle was pink and smooth. The muscle attached to the bone. Before our teacher reached the bone, she showed us other types of tissue. We saw fat and ligaments. The fat was white and smooth. It is used as a cushion. Next, we saw the ligaments. The ligaments were white. This used to help move the muscle tissue. The fats and ligaments are attached to the muscle tissue. When our teacher reached the bones, we saw the cartilage. This connects to the bones and is used to help the bone move around. Without cartilage, our bodies would be stiff as rocks. The cartilage was also white. In the chicken wing, there are also nerve tissues. However, in the chicken wing our teacher dissected, we were not able to see the nerve. If it was there, it would have been attached to the muscles.

This lab was done to show how a human's arm works. Almost everything is the same. The skin is the first tissue. Then comes the muscle. After that the fats ligaments are shown. Lastly, you will see the bones and cartilage. Additionally, the way a chicken's wing works is similar to the way a human's arm works. In both organisms, the skin is the first layer. It is always used to protect what is on the inside. The muscles move the same too. They both need the ligaments to help. The fat is used to cushion in both organisms. Lastly, the cartilage helps the bones move in both organisms. Although, there are two things that are different. The first one is that the muscle proportions are different in the organisms. The last one is that chickens don't have phalanges (finger bones).

Diffusion Lab

To demonstrate how diffusion works in a cell, we did an experiment with iodine and starch. In the experiment, we put a spoonful of starch and a small amount of water into a plastic baggie. Then, we filled a beaker halfway up with water. Lastly, we poured some iodine into the beaker and placed the starch baggie into the beaker. To finish the experiment, we had to let the baggie sit in the beaker for at least fifteen minutes.

After fifteen minutes, the starch in the bag was supposed to turn purple. This is because of diffusion. Diffusion is the term used to describe the process of molecules moving form an area of high concentration to an area of low concentration. In the lab, the plastic baggie was selectively permeable. Selectively permeable means that only certain things can go in and out. Since the plastic baggie was selectively permeable, the iodine molecules were able to go through the bag and spread into the starch. Once starch and iodine mix, they become purple. This is supposed to happen. However, in our lab the iodine molecules were not small enough to go through the baggie.

This experiment is a demonstration of what happens to cells. The plastic baggie represents the cell membrane. The starch represents the cell and the iodine represents things outside the cell. Our cell membrane is selectively permeable. This way only certain things can go into and out of the cell. For example, the cell allows water to come in and allows waste product to go out. However, it doesn't allow the organelles to go out or waste to come in.

Picture Source:

http://missbzscience.wikispaces.com/4b)+Diffusion+%26+Osmosis