Frog Dissection Lab

http://edweb.fdu.edu/folio/banborv/frogdissection/



This week, the Omega Science Lab dissected a frog in groups. As we cut through the skin, the first thing we saw was a layer of muscle. At first, we thought that it was more skin. Then Mrs.Russeau confirmed that it was muscle. Once we cut throught the muscle, we saw a clump of Fat Bodies under the liver. It looked like strands of spaghetti all tied together at the base. Above that, we saw the 3 parts of the liver. The right lobe, left anterior and poterior lobes. The liver looked a dark pea green and was the largest structure we saw. After all, the liver is not an organ in the digestive system. Then we pushed the frogs arms back to see the heart. The heart caused some confusion in my group. Some people including me thought that an astray lung was the heart. The others thought that a white triangular structure was the heart. I disagreed because I thought the heart would be red from blood. The next thing we searched for was the gallbladder and the spleen. The gallbladder was under the liver and looked like a oversized, squashed pea.



http://edweb.fdu.edu/folio/banborv/frogdissection/

The spleen was resistant when we poked it., Unlike the gallbladder and oviducts, it was hard and firm. We checked to see if there was still blood inside, but there wasn't. After that, we thought that our frog was a male since we didn't see any eggs stright away. Mrs.Russeau came again and lifted the stomach and intestines to show us that there were eggs in our frog. Our frogs eggs looked like little beads surrounded in a grayish whitish paste(below). We had to get rid of the eggs to see the oviducts and intestines. The oviducts looked like tiny intestines near the sides of the frog. There was a large j-shaped organ we confirmed to be the stomach. The stomach was connected to a long narrow tube that was the small intestine. We broke the strands that held the small intestine together to see exactly how long it was. Then at it's end, we saw a swollen tube that

http://magickcanoe.com/blog/2006/04/16/wood-frog-eggs-update-1/

we knew was the large intestine. We decided to cut open the stomach and the intestines to see if there was any food or waste still in there. The stomach and the small intestine were empty, but we got to feel the ridges in the stomach. The ridges were of different shapes and sizes.  We struck gold when we opened the large intestine. There was a greenish paste we knew was waste. Lastly, we examined the lungs. They were dark, shriveled and flat since there wasn't any air inside. They were located behind, and under the liver. Another great day in the Omega Science Lab. 

Endocrine System Animation

Endocrine System 4
by: Steelbrady

Digestion Lab 11/7-11/8

Today and yesterday, the Omega science lab performed an experiment that shows us how our stomach works. There were two days that were factored in this lab. On day one, we watched for immediate reactions when the components of each test tube went together. The components were; boiled egg whites, diluted hydrochloric acid, and chicken tenderizer( a pepsin). On day two, we looked to see if there were any long term effects on the components. Each test tube had a different combination or quantity of our components.

Day 1 
On day one, there were no immediate reactions when each of the test tubes components were put together. However, when we checked if a mixture of components were acidic, all the test tubes that had hydrochloric acid showed signs of acid in them. This tells us that hydrochloric acid is a, well....acid!

Day 2
On day two, we could definately see that there was a change. The test tubes that had one component( water, acid, pepsin) and egg whites did not show any signs of change. However, the test tube that had all those components did show signs of broken down egg whites.

As you see, in order for food to digest, there must be both a pepsin and hydrochloric acid working together, because without one, nothing will happen.

Chicken Wing Dissection

On Thursday, Omega science classes dissected a chicken wing. As the wing was dissected, we saw Muscles, Joints,  Ligaments, Fat, Skin and Cartilage. We also learned that human arms and chicken wings are very similar. Both have the flexor and extensor muscles. I also learned that when a joint is bent, one muscle relaxes and the other contracts. Also, two bones that are connected together with muscles and cartilage are called joints.

Diffusion Lab

The lab we did this week was about indicators. In this lab, our indicator was iodine. Iodine is considered an indicator because it turns purple when it comes in contact with starch. A prediction that my group and I made, was that the iodine would enter the baggie and turn the contents of the bag purple. As we watched the bag, our theory was proved correct. We were proud that we guessed correctly, but our question was: how? We learned that the iodine was able to enter because of two terms called, Diffusion and Osmosis. Diffusion is the spread of particles through random motion. In the lab, the iodine was able to mix with the water in the beaker because of diffusion. Osmosis is the movement of water molecules through a selectively permeable membrane. In the lab, the baggie was the selectively permeable membrane. Permeable membrane is a term that means ‘all substances are able to pass through’. Selectively permeable means that only specific things are able to go in. Since iodine is almost smaller than water, it was able to enter the baggie, turning it purple. But why would we need to mix iodine with water? The answer for that is a term called ‘dilution’. Diluting means to make thinner or weaken. Both definitions were used in the lab. The iodine was thinned so it would be able to pass through the baggie more easily. It was also weakened because the school does not allow students to handle pure iodine since it is dangerous and harmful to skin and clothes. Throughout the lab, the words, concentration, hypertonic, isotonic and hypotonic constantly popped up. Concentration is a large number of things collected together in one area (molecules). With that comes 3 subcategories, hypertonic, hypotonic and isotonic. Hypertonic is high solute concentration. Hypotonic is the opposite. If you guessed, hypotonic is low solute concentration. But then where does isotonic fit in? Isotonic is equal solute concentration.

Now I will talk about what happened during the lab. While we were watching, we noticed that when the starch in the bag began to turn purple, the iodine color became slightly lighter. I believe that we were able to see how the selectively permeable membrane works. The iodine’s color became lighter because the iodine molecules were coming through the baggie (selectively permeable membrane). Through this one lab, we were able to learn many different science terms. The indicator (iodine) was clearly shown when the starch turned purple. This lab helped me understand indicators, diffusion and osmosis.

          Some connections to life that I first thought of were hot chocolate powder, salt in a soup, cows at a farm, and books in my house. Hot chocolate mix spreads out when it is put into milk or hot water. The next example was salt in a soup. When salt is put into a soup, the salt affects the whole soup, not just a section because its flavor changes and increases the soup’s flavor when we taste it. The next example, cows in a farm, is a two step way to understand diffusion and possibly the best. The first stage is when all the cows are put in a barn overnight (iodine in a bottle). Then the next day, the farmer opens the doors and all the cows go out and graze in different parts of the field (diffusion). My last example, and this is a true thing, are my books. My books start in my living room on their shelves. Then as I read them, they spread out to my basement, family room, my bedroom and bathrooms. This may not be natural diffusion but they still have gone from a starting place to other rooms. 

Class Experiment 10/11/11

Based on the lab we worked on today, there are results for me to share. Firstly, I believe that the reason the lab took so long to complete was based on how fast the iodine entered the selectively permeable baggie. Since the bag was permeable, substances were able to enter the baggie. In this case, it was the iodine. Another thing I noticed was that the starch started turning purple from the bottom. The knot was half submerged, yet the smallest corner of the bag let in the iodine first. The molecules moved from a larger concentration are to a smaller area, because it moved from a 300 milliliter bearker into a tiny baggie corner.

Please subscribe to and/or follow my blog!

Welcome!

Welcome to my blog! This blog will be updated regulary. Feel free to post your comments or questions!