Common Ancestors Lab & Quiz

     In class on Tuesday, we paired up into groups and did a lab. We had the option between two labs, both dealing with common ancestry. Brian and I chose to do the lab that involved the creation of DNA strands with the use of different colored beads and a pipe cleaner. We made 4 in total, one being human, one chimpanzee, one gorilla, and one the common ancestor. We found that the chimpanzee and the human were the most closely related, and that all four species shared some common bases, so they all shared the same common ancestor. We clarified that the more similar the genes and DNA of the species, the more similar they are alike in nearly all features.

In order from top down, here are small sections of the gene that codes for the hemoglobin proteins of Humans, Chimpanzee, Gorilla, and Common Ancestor

Quiz Time

Part of our homework for tonight was to take a quiz on our blog, 

     so here goes my best attempt.

My Answers

1. The above picture shows morphological features shared between a common ancestor and its            

    descendants. There are homologous traits that can be found between all four of these species, 

    such as a similarity in arm structure. They all share the one bone, two bone, lots of bones      

    feature. When looking from the Mesonychid, to the Ambulocetus, to the Rodhocetus, to the 

    Basilosaurus, it can be seen that features such as the back legs did not appear and disappear 

    randomly, but rather gradually morphed over time, ending with the small flippers 

    at the base of the tail of the Basilosaurus.

2. e. North America

3. A dragonfly, a bird, and a bat all developed wings not as a result of homology, but rather 

    through convergent evolution. These shared traits are analogous, in that they formed as a 

    result of their environment, and did not originate from a common ancestor. Though they all 

    have wings, neither is quite similar to the other. A dragonfly has two wings on each side, a   

    bird has feathers on their wings, and a bat has a bone structure in their wings that is more 

    similar to that of a human arm. These three species gained their wings separately, as simple 

    adaptations to survive their environment. There is no direct link between any of them, they 

    did not evolve from each other.

4. In the Common Ancestor Lab, we created four different strands that each represented a small 

    section of the gene that codes for hemoglobin protein. Each hemoglobin strand represented a 

    different animal. We made one strand for a human, one for a chimpanzee, one for a gorilla, 

    and one for their common ancestor. The human and chimpanzee strands were the closest in 

    comparison, which explains why they appear to be very similar in structure, intelligence, and 

    more. With the common ancestor having the least similar DNA to humans, the 

    chimpanzee having the closest, and the gorilla somewhere in the middle, it can be concluded 

    that evolution exists, and that humans evolved from their common ancestor. While some of 

    the DNA experiences no change, other parts of the DNA change, leading to the formation of 

    a new species. This new formed species then experiences changes in its own DNA, and 

    forms yet another new species. DNA proves evolution, because similar DNA structures must 

    have originated from somewhere, and that somewhere is the common ancestor.

5. Homology is the study of the structural similarities or gene similarities between two or more 

    species, caused as the result of sharing a common ancestor. These similar features, otherwise 

    known as homologous features, are similar because they are inherited from a common 

    ancestor. These homologous features simply morph from this ancestor, they do not become 

    something entirely different. For example, the hand of a human and the hand of an ape are 

    said to be homologous, for they both inherited the characteristics of the hand of their common 

    ancestor. They cannot just change into wings over night. It would take millions and millions 

    of years for something like that to occur. In Your Inner Fish, an excellent example that shows 

    homology would be the one bone, then two bones, then blob of bones, then fingers structure 

    of the arm, as discovered by Sir Richard Owen. This structure can be seen in humans, seals, 

    lizards, birds, bats, penguins, and whales, among many other species. These similarities in 

    structure are no coincidence, but rather they all originated from a common ancestor with this 

    trait. It seems that this common ancestor was Tiktaalik, for it served as the transition species 

    from water to land, and was the first known species to have an arm such as this. Essentially, 

    all of the above species developed there arms similar to that of Tiktaalik, and therefore they 

    all share this homologous trait.

For homework, we also had to read Survival of the Sickest, chapter 4, and come up with a way to summarize it. I decided to do a poem. I added this poem below.

The buzzing sound of a million deaths,

was stopped at the site of a bean!

With the lack of an enzyme, the loss of red blood cells,

the blood would become too lean!

The tiny little beast, and G6PD deficiency,

two terrible diseases, many lives they have stole!

But together it’s true, throughout human evolution,

that this mutation has saved many souls!

Favism is so prevalent, and Pythagoras was right,

Eating fava beans was making his students sluggish!

Primaquine was the key, to the discovery of this disease,

in the Korean War where many soldiers perished!

But little did we know, that survival of the sickest

would lead to convergent evolution!

Favism would prevail, protection from malaria,

It was an illness that became part of the solution!

Fossil Day

     We started out the class by receiving our tests back. I did a lot better than what I was expecting. We then reviewed all of the multiple choice to make sure that everyone understood what they did wrong. Other than a few clumsy mistakes, I pretty much knew everything. I just need to make sure that I pay more attention to every detail of the question and the answers, and not just see that the first part of the answer sounds right, and move on without reading the rest of the answer thoroughly.

     The rest of the class we talked about the subjects that chapter 1, 2, and 11 of Your Inner Fish covered. We learned about how plate tectonics affects where a fossil will be found. For example, the fossil of a fish that might have existed in a tropical area near the equator may be found in places as far as the Arctic, because the plates might have shifted dramatically since that animal died.

Plate Tectonics

     We learned about how Tiktaalik adapted to better suit its environment, and how its changes included having a neck, a wrist and arm that allowed to do push-ups, a flat head, eyes on the top of its head, an expanded ribcage, and many more adaptations. This adaptions allowed it to survive by helping it protect itself, and hunt its prey better.

Tiktaalik Adapted To Survive

     We learned that the sequence of a wrist is similar in many different animals, due to the fact that they have common ancestors that held this trait.
     

We reviewed the basic idea that the older rocks are on the bottom, and the newer rocks are on the top.

At the end of class, we took a little trip over to the Alf Museum, and took a look at Tiktaalik. We discussed his features in the museum, then came back to the classroom and discussed them some more.

Test Day

     Tuesday was our test day, and it went well. I only missed three multiple choice questions, and I got a perfect score on my graph and writing part. I was a little concerned that my writing section would be confusing to read, but I guess it was better that I had thought. Luckily, I did the Diffusion and Osmosis Lab, so i was exposed to this kind of problem already. Im glad to say that I did very well, despite only getting 2 hours of sleep the night before. The questions that I missed are quite clear to me now. They were mostly errors in interpreting the questions and paying attention to the little details. The biggest thing I learned out of this situation is that I should finish the entire lab report on the weekend, so that I can study and get some sleep before the test.

Get Sleep

Funny Joke

     Our homework for the class after the test was to read Chapters 1, 2, and 11 of Your Inner Fish. When reading this book, I found Neil Shubin's journey to be very interesting. Even though Shubin  failed time and time again to find the fossil of the species that started the transition from water to land, he and his crew were persistent and never gave up. It was after years and years of searching at a site on Ellesmere Island in Canada that they finally found Tiktaalik.

     The first chapter taught us about the process in which remains of an animal go through in order to become a fossil. We learned that a fossil is formed when it is covered by sediment, and compressed into the ground. The soft tissues of the bones are replaced by rock, in a process known as mineralization. Some of these fossils move do to shifts in the plates, and a lucky few are discovered by paleontologists. We also learned that it is best to search in an area where the rock is the same age as the desired fossil, and to search for fossils that are disposed.

     In the second chapter, we learned that creatures as different as humans and frogs share an arm bone scheme, starting at the shoulder, with one bone, two bones, lotsa bones, then fingers or toes. This discovery was made by Sir Richard Owen. This discovery shows the presence of homology, for these creatures received these traits from a common ancestor. If these creatures all developed these same traits, but did not receive them from a common ancestor, then they would be analogous to each other. Convergent evolution is what causes two animals to develop a similar trait without receiving the trait from a common ancestor.


Tiktaalik

Review Day

     In the class before the test, we spent the majority of the class reviewing content. The greatest portion of the review was on macromolecules. In the later part of the class, we took a quiz that consisted of basic chemistry, and macromolecules (including subjects such as structural isomers). We had our quizzes graded in class, and I got a 100%.

     The weekend after this class, I spent a lot of time working on my lab report, and a small amount of time on a house case write-up. I chose to due the Diffusion and Osmosis Lab, and I worked on it up until four a.m. in the morning of the night preceding the test. The end product turned out to be about 15 pages in my composition book. I think that I answered all of the questions very well, and think that I had very solid hypothesis, graphs, and conclusions. I spent only about 30 minutes studying for my test, so I hope to manage my time better for the next test.

     Here is my final lab report for the Diffusion and Osmosis Lab.

Who took Jerell's iPod?

9/12/13

    In the last Honors Biology class, Wednesday September 11th, we started out by showing our knowledge of macromolecules. We learned about Carbohydrates, Proteins, and Nucleic Acids for homework the previous night.

Nice picture of cell structure.

Another thing that we leaned included the synthesis and breakdown of polymers, known respectively as dehydration and hydrolysis. There were tons of other things regarding macromolecules that we learned, but it would take forever to go into detail of each one.

     After the macromolecule review, we begun our Organic Compounds Lab. There were two experiments to choose from, and Brian and I chose to do the mystery lab, which was titled Who Took Jerell's iPod? What we did first was test Vegetable Oil, Glucose, Starch (either from corn or potatoes), and Powdered Eggs for Glucose, Starch, Proteins, and Lipids. The Benedict's and the Iodine test came out as expected, with the with the Benedict's(glucose tester) turning orange for the Glucose, and the Iodine(tests for starch) turning a mixture of dark blue, indigo, and black upon contact with the Starch. For the other two tests, we got some results that seemed a little obvious as well. The Bluret, which tests for Protein, came back positive for the Powdered Eggs, turning a lavender color. For the Sudan III, a lipid tester, we got positive results for the Vegetable Oil.

     The two tests pictured below were used for testing Glucose and Lipid. The first test shown below is the Benedict's test, and this shows if Glucose is present. If there is Glucose present, it will turn an orange color as seen in the second picture below. The other test, image 3, is a paper bag test, which tests for the Lipids. We ended up abandoning the paper bag test however, and changed to a must faster Sudan III test, that also tested for Lipids.

Benedict's test at the start.

Benedict's test after a few seconds.

Abandoned paper bag test for lipids.

     The Bluret (Protein Tester) and the Sudan III (Lipid Tester) results are shown below in this picture.

The Bluret test positive for Powdered Eggs, the lavender bottom and third from the left
The Sudan III test positive for Vegetable Oil, the bright red one in the middle left. 

     Next, we did the same four tests on Pretzel crumbs, Butter, Jelly, Fat-free yogurt, and Beans. For the  Benedict's test (Glucose), we got that Jelly tested positive. For the Iodine test (Starch), we got that Pretzels and Beans tested positive. For the Bluret test (Protein), we got that the Fat-Free Yogurt tested positive. And for the Sudan III test (Lipids/Fats), we got that Butter and Beans tested positive. The Buret and Sudan III tests can be seen for all five samples in the picture below.

     The last two things that we tested were a dry part of Jerell's evidence, and a liquid part of Jerell's evidence. After doing all four tests, we determined that the liquid sample came back negative for everything, but the dry sample tested positive on the Iodine test, turning black. This means that there was Starch present in the dry food sample of the person who stole Jurell's iPod.

     Since the Pretzel and the dry sample both tested the same in all three tests, it can be inferred that the thief was eating a Pretzel for lunch. The only person who had a Pretzel during lunch was Kiara, so it must have been Kiara who stole Jerell's iPod. Case closed.

Macromolecules and House Case

9/10/13

     We started Friday's class, 9/6/13, with a quiz on graphing. I did ok on this quiz, but I did mess up on the part which asked for some standardized variables, and the part that involved naming the graph. All in all, I got a 2 on the quiz, which is something I can live with.

     After the quiz, Mr. Quick taught us about macromolecules. He taught us that there is a BiLayer, made up of phosphate and lipid, called Phospholipid. We learned that the lipid is Hydrophilic, likes water, and the phosphate is Hydrophobic, afraid of water. We learned that the combination of imbedded proteins and carbohydrates is called a Glycoprotein. Glycoproteins and Glycolipeds, which contains carbon, hydrogen, and oxygen, both act as functions, and can communicate by chemically talking. We also learned about how proteins act as transportation systems, and allows water to travel through. Proteins also allow other things to pass through, and can even help pull things through. Proteins can sense the things that touch them, and communicate it through to the other side to find out if it should be allowed to pass through or not.

     We also review a bit of Osmosis and Diffusion, and how they can both be controlled by the selectively permeable cell membrane (security wall). We also learned that active transport needs energy, and that Facilitated Diffusion needs help, which it receives from either a channel or a carrier.

     The rest of the class we did the House Case. Anthony, Calvin, and myself volunteered to be the doctors for this case. We wrote on the board the symptoms that the 18 year old high school cross-country runner had, which included headaches, vomiting, tiredness, and confusion. We put some tests that we would run on the patient, which included checking his vitals and temperature, blood tests, and brain scans. These are all shown below. 

Kidney Test not seen in picture, is off to right.

      Then we came up with all of the possible diagnosis, and began asking Mr. Quick some questions. Some notable answers were that he was unsure if he had diabetes, said that he drank alcohol on the weekends, and that he drank three gallons of water during cross country practice. All of the diagnosis are shown below.

     After getting back the results from some tests, we eliminated some diagnosis in class, seen as crossed out in the above picture. The remaining ones were Dehydration, Over hydration/Hypernatremia, Heat Exhaustion/Stroke, Gastroenteritis, Sleep Deprivation, and Migraine. With only these left, and the others already eliminated during class, I got started. The results said that his Serum/Blood Na level was 125 meq/L, and I found that a normal Serum/Blood Na level is between 135-145 meq/L. I also found that a low Serum/Blood Na level, which is seen is this patient, occurs when there is an increase in water intake. The next results were the Serum Osmolality, and it said that his was decreased. I found out that a decrease in Serum Osmolality can be a result of drinking too much water. The next test was a Urinalysis, and it showed that his Specific Gravity had decreased. This is once again, this would be caused by an excess intake of fluids. The last result shows that that the patients blood pressure was slightly elevated, which can be caused by an increased amount in water intake. With the findings in all of these tests, and the fact that he admitted to drinking 3 gallons of water, it is pretty clear that the patient suffered from over hydration, otherwise known as Hypernatremia.

Diffusion & Osmosis Part 2

9/5/13

     Our homework prior to our 5th class of Honors Biology was called House Case #1, in which we had to come up with 3 diagnosis for a patient. The patient in this case was an 18-year-old high school cross-country runner, and the issue is that he began vomiting and complaining about a severe headache at his cross-county practice. He also said that he was very tired and confused.

     For my three diagnosis, I chose heat stroke, dehydration, and head trauma, such as a confusion. I found that the symptoms of all three of these possibilities included vomiting, headaches, tiredness, and confusion( among other symptoms). I will wait until next class to go into the details of my arguments for each of these hypothesizes.


During this class, we discussed the results of the experiments from the previous class, and drew graphs in order to find out the molarity of the four different potatoes tested.

Graph showing the estimated molarities of the potatoes. The % mass change was used
as the y-axis, and the molarity of the six solutions was used as the x-axis.    

     The point in which the lines cross the x-axis can also be seen as the point where the mass did not change. If the mass did not change, then the cell and the outside solution had the same molarity. So in essence, the point which the line crosses the x-axis will be equal to the molarity of the cell, or potato. Each above molarity was estimated through the use of the graph. 

     We also did an experiment where we put 7ml of a solution with a composition of 15% glucose, 5% starch, and 80% water into a dialysis tube. We then used a glucose strip to test the solution in this cell, and the strip turned brown. We also tested the water with the glucose strip, and that resulted in no color change, reassuring us that their was no glucose already in the water.  Next, we placed the cell into a cup of water so that it was covered, and waited for about 15 minutes.

Glucose/Starch cell sitting in water.

     Then we added iodine to the outside solution. Since starch is an indicator for iodine, the iodine should turn dark blue/black where starch is present, and brownish-yellow where there is no starch present. Since the outside solution turned brownish-yellow, it can be reasoned that the starch was not able to make it though the dialysis tubing.

     Since the starch was not able to pass through the dialysis tubing, the concentration of starch in the cell remained the same. And when iodine, which was able to pass through the dialysis tubing, was added to the cup, it reacted with the starch and turned dark blue/black.

Iodine added

 
We also tested 7ml of the starch/glucose solution in a cup with 1ml of Benedict's. Once these two were added together in the test tube, we heated it in water, so that the reaction would occur at a faster rate.


   

     The color that the solution turned can be used to determine the amount of glucose. Since this solution turned orange, it can be determined that there is a lot of glucose in the solution.

  We also did an experiment where we let three different sized "cells", one representing long hair cells, one skin cells, and the other one a plant cell.

     We covered three different shaped cells in NaOH, and another three different shaped cells in KI, and measured how far they diffused after two minutes. Each cell diffused between two and three millimeters. We measured the surface areas of the three cells and recorded them. It appears that the solutions will be able to seep into the nucleus faster.

Diffusion & Osmosis

9/3/13

    Prior to our 4th Honors Biology class, we were assigned to do a two things for homework.

       First, we were asked to find out why red cabbage is a suitable pH indicator, how the chemistry of acids and bases affect this indicator, and explain how acid rain would affect red cabbage growth and development. The answer to the first part of this is that red cabbage contains a pigment molecule called flavin, which is an anthocyanin (an anthocyanin is known to turn red, purple, or blue depending on the pH). The answer to the second part of the question is that the colors of the pigments change color in response to changes in hydrogen ion concentration, or pH. When acids donate hydrogen ions to the solution, the hydrogen ion concentration of the solution increases. High hydrogen ion concentrations cause the pigments in the red cabbage indicator to turn red. When bases are added, the hydrogen ion concentration decreases, because the base accepts the hydrogen ions. Low hydrogen ion concentration causes the red cabbage indicator to turn greenish. A neutral hydrogen ion concentration would result in a purplish color. Finally, the answer to the last part of the question is that the red cabbage would grow and develop more slowly in acid rain, because acid rain contains less water than regular rain, making it harder to photosynthesis. Additionally, the acids would seep into the plant and dissolve some of the sugars that make up the plant. This may cause the cabbage to be weaker and break more easily.

     Second, we had to review 8 concepts pertaining to diffusion and osmosis. We learned that diffusion is the tendency of molecules to move from areas of higher concentration, to areas of lower concentration.

      We then learned about osmosis, which is basically diffusion involving water. In osmosis however, water has to move through a selectively permeable membrane, which allows some types of molecules, and restricts others.

Water moves from high concentration to low concentration.

     When a cell is involved, the movement of water is influenced by the solute concentration of the solution. If there is a higher concentration of solute in the cell than in the solution, then the water will move in, if there is smaller concentration of solute in the cell than in the solution, then the water will move out. This is the basis on which we tested our experiment.

     For our in-class experimental lab, we created six cells using dialysis tubing, each about 7ml. Then we dried the cells, removing excess water weight, and massed them. Then we put each cell into a 50ml cup of water, covering the cell completely. We let them sit in the cups for 30 minutes, and then re-massed the cells and collected our data. With the exception of two cells, our data showed that the cells gained mass. This means that water moved into the cells, where the water concentration was less.

A picture of the cells that we used.

We then re-did this experiment, but put Gatorade inside of all six cells, and and covered each of these cells with 50 ml of the six different colored solutions. We weighed the dried cells before putting them in the solutions, then came back at night to weight the cells after a day of sitting in the cups. Our data showed that the % mass change for each of the cells was negative, and with the exception of one cell, the % mass change of the cells went in the same order as molarities of the solutions in the cells, with % mass changes=low molarity, and high % mass change=high molarity. This shows that the solute in the cells diffused to areas of lower concentration, which in this case was the water. With less solute remaining in the cell, the mass of the cell decreased, and that explains why the cell with the most solute lost the most mass. Since the blue cell had the least % change in mass, it can be reasoned that it had the closest molarity to the gatorade.

We also learned terms such as the following:

Hypotonic- lower solute concentration/higher water concentration

Hypertonic- higher solute concentration/lower water concentration

Water moves from Hypotonic --> Hypertonic

Isotonic- Equal in concentrations

Water Potential-  Tendency of water to leave one place in favor of another.

Water moves from Higher Water Potential --> Lower Water Potential

Plasmolysis- process in plant cells where the cytoplasm pulls away from the cell wall due to loss of water through osmosis.

Cytolysis- Occurs in a hypotonic solution. The net flow of water goes into the cell




      

Water

     
Blake Williams
9/1/13


      During our third Honors Biology class, and for homework the prior night, we learn about all of the different properties of water. First we learned that H2O is polar, and that the reason for this is that the electrons between the oxygen and the two hydrogens atoms are not shared equally (the reason that the electrons are shared is because water is a covalent molecule). The six protons in the oxygen atom are able to pull these shared electrons with a greater force than that of the two hydrogens (for each only contains one proton).

H2O

H2O Water Molecule

Electronegativity Charges

This diagram shows that
the electrons of the two
hydrogens are being pulled
toward the oxygen atom.
This is due to the higher
number of protons in
oxygen than in hydrogen.

The water's polarity is shown in this molecular structure.

           



     We found out that a water molecule is capable of hydrogen bonding with up to four other water molecules. This is because the two hydrogen atoms can bond with two oxygens from two other water molecules, and the one oxygen is capable of bonding with two hydrogen atoms from another two water molecules, adding up to four in total. The diagrams below represent this process.

This figure represents the
attractions between two
water molecules.

The figure shows who one water molecule is capable of
hydrogen bonding with four other water molecules.

     The final properties that we learned about both involved the attractions of the water molecules. The first was cohesion, which is the attraction between the many water molecules. The second is adhesion, which is the attraction between the water molecules and another surface.

Cohesive

Hydrogen bonds hold all of the water molecule together.

Since hydrogen bonds cause the water molecules stick together,
insects such as water striders are able to walk on the surface of a
pond without breaking the surface. Their thin legs, with small spread-
out hairs which are not visible in the picture, are able to sit on top of
the hydrogen bonds. this is because their weight is spread out over a
large surface area.

A paperclip behaves the same as a water
strider when places on a surface of water
(For our class, we use a toothpick instead).

Due to cohesion, water forms a convex surface when a glass is slightly
overfilled. The cohesive forces (between the water molecules) is stronger
than the adhesion forces (between the water molecules and the outer surface
of the glass. There is a very strong surface tension in this figure, and it is due
to the fact that the water molecules on top have no water molecules above to
bond with, causing the bonds that they do make to be much stronger than any
of the bonds below.

Adhesive

Water molecules are attracted to
the toothpick.You can see the
water move up the paperclip.

Similar affect with a straw. This affect
is occurs because the water molecules
are polar, and therefore have a charge.
This charge is attracted to the charges of
the straw or other surfaces.

The water molecules can be seen moving
up the paper towel. this is due to both
cohesion and adhesion. The water molecules
are attracted to the paper towel, and also
attracted to other water molecules.

Combination

Cohesion and adhesion often work together.
In this picture, the water molecules are sticking
to the leaves, and those not in direct contact to
the leaves are sticking to the other water molecules.

The water molecules stick to the penny,
as well as to other water molecules.

The cohesion allows the water to stick together in one
continuous stream, while adhesion causes this stream to
stick to the xylem wall and rise up. As the water molecules
in the leaves are removed by transpiration, the water
molecules in the stream below rise up and take its place.

   We also discussed how water affects climate and temperature fluctuation. We learned that the reason costal areas have milder climates than adjacent inland areas is because water has a high heat capacity. It requires 3200X more energy to change water by one degree than it takes to change air by one degree. This is the same reason that ocean temperatures fluctuate much less than air temperatures on land. The water in the air breaks apart, but unlike air it is able to keep reforming. Since the molecules are not being broken apart as much, the molecular motion does not increase or decrease as much as it does in air.

     In class, we learned why ice floats on water. We learned that when the water is liquid, there is molecular motion, and the molecules are close together. But when the water freezes into ice, and the molecular motion stops, the water molecules form crystalline hexagon structures (because the angle between the two hydrogens and the oxygen is 120 degrees). These hexagon structures are more spread out, allowing more empty space between all of the water molecules. This extra empty space makes ice more dense than water, and that is why it floats.

     Near the end of class, we talked about why human sweat and dogs pant to cool themselves. We learned that by sweating, humans release heat, because when the water is release from a human's sweat glands, it is evaporated and sent into the air (evaporation=exothermic. Therefore the heat is released from the body). Since dogs do not have sweat glands, they use the water on their tongues instead. The process results in a release in heat through evaporation as well. Mr. Quick also explained to use why this process is more difficult in humidity. He said that since their is already water saturated in the air, you body cannot produce sweat for it cannot be evaporated.

    The last thing about water that I learned is that when it dissociates, it produces hydronium (H3O+), with a concentration of 10^-7 in pure water, and hydroxide (OH-), with a concentration of 10^-7 in pure water as well. Acids contain H3O+ and bases contain OH-.

     My partner for the day was Brian Christiansen, and we worked on the problems involving why a water strider can walk on water, and why water formed a convex surface when a glass was overfilled.