Digestion Lab

In science class, we did a lab that helped us understand how digestion works. We had four test tubes labled A, B, C, and D. We put three pieces of cut up egg white in each test tube.  In test tube A, we put in 10 mL of meat tenderizer (A.k.a pepsin) and there was no immediate reaction. In test tube B we put in 5 ml of pepsin, and 5 mL of water and again, we didn't see an immediate reaction. In test tube C, we put in 10 mL of hydrochloric acid, and we could see the liquid bubbling, and small holes already forming in the egg white. In test tube D, we put 5mL of pepsin, and 5 mL of hydrochloric acid, we also didn't see an immediate reaction. We used strips of blue litmus paper to see how acidic the solution was. In test tube A, our litmus paper stayed blue. In test tube B, it stayed blue, but was wet. In test tube C, our litmus paper turned an orange/pink color, because it was acidic, and in test tube D, it also turned orande/pink because it was acidic. The next day, we looked at our test tubes again, and there were some major diffrences. In test tube A, the egg white was almost all disintegrated, but in test tube B, there wasn't a reaction. In test tube C, the eggwhite was almost all gone because the acid had broken it down, but in test tube D, there wasn't a reaction. We used the litmus paper again, and the paper stayed blue for test tubes A and B.  The litmus paper turned orange/pink again for test tube C , but not for test tube D. The first day the litmus paper changed but now it didn't because the acid probably wasn't there anymore. This lab was a good way to show how the digestive system worked, because the hydrochloric acid in our stomachs works the same way.

Chicken Wing Dissection Lab

In science class our teacher dissected a chicken wing, and we observed the different parts. First we looked at the skin, which was bumpy because feathers had been pulled out. Then after she made a cut, we saw the fat which was right underneath the skin. After the fat, we saw the muscles, which she pulled and squeezed, and the wing moved accordingly. Then we looked at the tendons, which were at the end of the muscles, and attached to the bone. After our teacher pulled off all of the muscle, we saw the joints which connected the bones, and the ligaments that were connected to the joints. Lastly, we saw the cartilage which helps the bone move without them touching each other. This lab really helped me understand the different types of tissue better.

Diffusion Lab

          In our science class today, we tried a diffusion lab. We put cornstarch and water in a plastic baggie, and put water and iodine in a beaker. We then put the baggie into the iodine solution and waited 15 minutes. The cornstarch in the baggie was supposed to turn purple, but it didn't work because the baggies were too strong, and the iodine didn't get through. I think the lab would have worked if we had cheaper baggies or if we waited longer.

Tree Hugger? Or Not?

In recently read an article about a type of vine that curls around a tree's trunks. In Barro Colorado Island, Panama, there is a type of vine (Liana) that curls around trees and grows up to take their sunlight and water. Scientists have come to the startling conclusion that these vines are slowly taking over tropical rain forests. These vines are parasites that use the trees as their host. The Liana are a great source of food to animals during the dry season, because they flower and fruit at that time when most trees don't. They also provide a sort of "highway" in the canopy to the animals because they snake through the trees when they grow. This weed takes most of the sunlight, water and nutrients that a tree needs. They can also stop a tree's growth and over time kill it. I think that we should get rid of this vine, because our rainforest's are already small, and we don't want them to get any smaller because of a problem that we can fix.

The article I read can be found at the following website:http://www.nytimes.com/2011/05/24/science/24vine.html?ref=science

Sea Lions Sentenced to Death?

I recently read a very interesting article, that was quite intriguing. Sea Lions in Oregon and Washington have been sentenced to death, by the government. Their cause: eating endangered salmon. The states will be allowed to kill up to 85 sea lions a year, but only the ones that eat salmon. Last year this idea was struck down, because animal rights groups filed a lawsuit. Before the government made this horrible desicison, they tried to scare away the sea lions by using firecrackers, loud noises, and rubber bullets. I don't think the government should do this because, the sea lions don't know any better. To them, the salmon is just food. Before the government does this, I think they should try harder to move the sea lions, because this is a harsh and cuel way of doing it.

The article mentioned in this piece can be found at: http://green.blogs.nytimes.com/2011/05/15/salmon-eating-sea-lions-sentenced-to-die/?ref=earth

My Soaring Straws Lab

In class we recently did a lab, with toilet paper rockets. We pulled back the straw on the rubber band to get the elastic potential energy. I found out that the more Elastic Potential Energy (EPE) there is, the more Gravitational Potential Energy (GPE) there is. The EPE which was the amount of stretch in our experiment was the manipulated variable. It is the manipulated variable because we changed how many centimeters we pulled the straw back. The responding variable was the height, because depending on how far back we stretched the straw, the height changed. When I stretched the straw back 1cm, my average height was 2.09m, which is different from when I stretched the straw back 5cm, the average height was 6.28m which is higher. So, when I had more EPE for my 5cm trial, my GPE was 115.23mj, but when I stretched it back 1 cm, my GPE was only 34.85mj.

Some errors in my lab were that we did this over a period of days, and all the different classes used the same rockets, so I don't know if the rubber band on the rocket broke in other classes or not, but in my class it did. Also, the toilet paper tube bent down more on the sides, so the results might not be that accurate. I also had a hard time seeing exactly how far the straw went up because sometimes the straw went to the left or right. We could make this lab better by getting stronger materials, because then we wouldn't spend so much time trying to rebuild our rocket, and our data would be more accurate. I also think we should build our own individual rockets, because then our own data would be more accurate.

My Toothpick Fish Lab

                                                                I recently did a lab in science class, and the results I came up were very interesting. We had three fish of diffrent colors that all lived in a pond near a waste factory. ( Fish colors: red,green, yellow) The dominant alleles were green, while the yellow and red alleles were ressecive. When we paired up the fish, their genotypes showed that most of them were green, but the yellow ones died because they wern't camoflauged well enough in the pond that was filled with green algae. ( The red fish could hide easily) For every generation, I took out the yellow fish because they were eaten. When I got to the 4th generation, there was a natural disaster and all the green fish died.

          When the natural disaster happened, the population of the fish was just wiped out. The physical characteristics of the green fish gave them away, because all the green algae died from the toxic waste that was dumped into the pond. Accidents like this could be avoided in real life life we didn't build factories near wild life areas. As I said before, the population was just wiped out. Depending on the ecosystem, it may not be be just plants that die but animals too. We should pick good places before building things that are harmful to the environment like factories.



( We used colored toothpicks to do this lab, and no animals or plants were injured while doing this lab. This situation was fictional and did not happen, but the concern is serious.)