Thursday, September 26, 2013

Evidence for Evolution Quiz

1. The picture shows evidence for land to water evolution. It shows that the land animal evolved into a whale by first, his feet becoming webbed and losing his fur. Then, his limbs begin forming into fins and his tail is now the tail of a whale, and his body is now covered in scales. Lastly, his arms and legs fully transform into fins, and his head becomes longer and more like that of a whale's, as his entire body is now whale-like after adapting to the conditions of the ocean.

2. E, North America.

3. These organisms show convergent evolution because although they all have wings with similar functions, they have analogous structures because the bone structures are completely different. They show convergent evolution because they are all completely different species, but have evolved to have wings that have the same functions.

4. The Common Descent Lab shows DNA evidence and ancestry as evidence for evolution because in it we compared the DNA strands of gorillas, humans, chimpanzees, and the common ancestor, and we were then able to discover that chimps and humans share a common ancestor and that gorillas were the most similar to the common ancestor of the three species. We could then use this evidence to determine which species evolved from the ones that we studied.

5. Homology is the similarity of the bone structures of certain limbs that organisms share with a common ancestor. For example, pterodactyls, humans, and tiktaaliks all share the same "one bone, two bone, blob" in the arm and wrist area. Homology is used to determine transitions in the fossil record, for instance the evolution from water to land. Tiktaaliks share many homologies land animals, showing that although it lived in the water and looked similar to a fish, it also had the same bones to allow it to move onto land and thus supports the evolution of water to land animals.

Blog Day 9

Today, we covered DNA aspect of evolution. We divided up into small groups and worked on different projects. James and I found the similarities between monkeys, gorillas, and humans by creating DNA strands for each like these below:

Here's what the chimpanzee DNA strand looks like:

And the positioning:

Here is the positioning for the gorilla DNA strand:



And the positioning for the human:

Upon analyzing the strands, we found the chimpanzee and the human strand to be very closely related. Upon studying the gorilla strand, we found it very close to the common ancestor strand:

Thus, we came up with this common descent model:


This model shows gorillas, chimps, and humans all having a common ancestor, chimps and humans having a common ancestor, and gorillas being the closest to the common ancestor that they all share. 

Blog Day 8

Today, we began our introduction to evolution. We studied tiktaalik and went up to the museum to study the transitional features that tiktaalik has. It was really interesting to piece together the transition from water to land as tiktaalik contains features of both.
Here is tiktaalik half in, half out of the water. The bones in its wrists allow for it to do push-ups, or push the bottom of tiktaalik quickly through shallow water and away from predators.


We finished the class by taking a short quiz.

Wednesday, September 18, 2013

Test Day

Today we did the Unit 1 test. It was challenging but fairly easy if you studied.

Monday, September 16, 2013

Macromolecule Mystery

To begin the class, we did white board activities regarding the notes we took for homework.
Then, we moved on to the Macromolecule Lab.

Macromolecule Mystery

The object of the lab was to find out who stole Jerell's iPod by testing 5 substances and 5 foods that contained those substances to see which matched the dry and liquid evidences.

Procedure

1. First, we placed small amounts of vegetable oil, glucose, starch, egg whites, all mixed with a tiny bit of water, and water into small containers of a plastic tray.
2. Next, we placed a drop of each substance onto a paper bag to test for lipids.
3. Then, we placed each substance into a tube with 10 drops of Benedict's to test for glucose.
4. After, we placed iodine in each of the substances to test for starch.
5. Finally, we placed biuret in each of the substances to test for protein.
6. We then repeated this process except instead of the substances, we used 5 different foods: pretzels, butter, jelly, fat-free yogurt, beans, and the dry part of Jerell's evidence, and the liquid part of Jerell's evidence.

Results/Conclusion

The results for the substances are as follows:





The results for the foods are as follows:


IMG_2406.jpg


Thus, we found the thief to be Kiara because her pretzel was the only substance with starch and nothing else, while the evidences had only starch and nothing else.

Diffusion an Osmosis Day 2

To begin the class, we started with a white-board session on graphs reflecting the data from the previous class. Our white board is as follows:

IMG_4024.jpg

We then moved onto the Diffusion and Osmosis Lab.

Lab

1. First, Sid, James, and I created a cell with the dialysis tubing from a solution that was 15% Glucose and 5% Starch.
2. Then, we tested the cell to ensure that there was glucose and water to ensure that there wasn't, with a glucose strip. Then, we stuck the cell in a cup of water.
3. We added iodine into the cup to ensure that nothing leaked out of the cell, because if the cell leaked, then a reaction would occur with the iodine.
4. We let the cell sit for 15 min, then we tested the solution in a tube with 1ml of  heated Benedict's. The Benedict's is used to react with reducing sugar, i.e. the glucose in the solution, thus explaining why we tested the solution with Benedict's.
5. While we were waiting for the cell, we then cut up three slices of phenol and filled three different cups with NaOH.
6. We measured the three slices and calculated the surface area and volume of each.
7. We stuck the cubes of phenol into the NaOH and immediately they turned pink.
8. We then let them sit for a few minutes.
9. We took the cubes out and measured the volume.
10. We took out the cell we created and found it to have turned blue from the reaction.

Conclusion

The glucose and starch molecules were unable to pass through the cell membrane of the bag because they were too large. The molecules of the water and iodine, however, were small enough to diffuse through the semi-permeable membrane and thus caused the reaction.

The volume of the cubes decreased because some of the phenol molecules transferred into the NaOH to reach equilibrium.


IMG_2517.jpg
The cell sitting in the iodine-diluted water.

IMG_3213.jpg
The cell after the reaction.

House Case Day

To begin class, we started by discussing the characteristics of the cell membrane. Then, we took a quiz regarding lab data and graphing. Next, we discussed the House Case.


House Case

We first went over the various symptoms that the cross country runner displayed.

Then, we thought of tests we could conduct to test the symptoms.

After, we wrote down several diagnoses of the cross country runner.

Finally, we eliminated some of the diagnoses that had to be false and left class with an answer in mind.

Conclusion

The cross country runner drank an excess of water during the run, after he had lost a lot of sodium in his sweat. This caused an inbalance of the sodium and water levels in the body, resulting in his symptoms. This is called hyponatremia.

Diffusion and Osmosis Day

We began Honors Bio Day 4 with a short quiz regarding water. Then, we went right into the Diffusion and Osmosis Lab.

Diffusion and Osmosis Lab

1. First, Sid, James, and I created six cells by filling up six plastic bag/tubes with six different solutions and different molarities.

2. Next, we weighed the cells and stuck them in water for 30 minutes.

3. Then, while we were waiting, we filled up six more bag/tubes with Propel and weighed those.

4. After, we stuck those in the different solutions and covered the glasses with parafilm.

5. We then took out the cells and weighed them to get the following mass change percentage (By subtracting the initial mass from the final, then divided by the initial):

Clear 6.7%
Red 20.2%
Yellow 17%
Green 9.5%
Blue -1.3%
Purple 17%

6. Sid came back at night and got the following mass change percentages of the Propel:

-28% for the 5.3
-51% for the other 5.3
-10% for the 5.9
5% for the 4.9
-20% for the 4.77
-37% for the final 5.3
 
 
 
 
The cells after drying them.
IMG_2361.jpg
The propel in the solutions.
IMG_2362.jpg
 
 
 Conclusion
The solutions all gained mass in the experiment because of the addition of water through diffusion and osmosis (ignore the negative one, there was a leak). The propel all lost mass, meaning that it had a higher concentration than the surrounding concentration, forcing the water to travel to the lower concentration and out of the Propel bags.

Water!

To begin the class, we took a quiz on basic chemistry. Then, we answered questions that dealt with our homework on white boards. When we came to a question about why water forms a convex shape when it slightly overflows. To study this concept, we did a small lab with pennies.

Penny Lab

1. We dropped droplets of water onto the penny until it was slightly overfilled.
2. We stabbed the convex "bubble" with a toothpick and observed that the water stuck to the needle as it was pulled out, but didnt overflow off of the penny.
3. Then, we dipped the toothpick in dishsoap and stuck it into the bubble.
4. This time, the bubble broke because the hydrogen bonds were broken by the dish soap and the water in turn overflowed.

Blog Day 2

Day 2
For the second day of class, we were given the choice between three worksheets, which would all satisfy a standard. I chose to do a worksheet regarding the basics of the Lewis Dot structure of Ionic Bonds and Covalent Bonds. Upon completion, I took the formative oral and written quiz about Basic Chemistry. That was all for day 2.