Quiz- Evidence for Evolution

Name: Calvin Li

Block: A Block

Honors Biology

Evidence of Evolution Quiz

1. Explain the following picture in terms evidence for evolution.

The picture shows the evolution of whales from being a land living animal to a sea living animal. We can see that the Mesonychids from 55 mya had four limbs and it is obvious that they walked on land. However after 3 my at 52 mya, we have the Ambulocetus that still had limbs, but that were a lot shorter compared to those that the Mesonychids had, they most likely lived both on land and water, they would've swam by paddling their hind limbs. Later at 46 mya, the rodhocetus had already reduced their limb size so that they couldn't walk therefore live on land anymore, and they started swimming by moving up and down like modern whales. The Basilosarus were very similar to modern whales except that modern whales dont have their rear limbs sticking out anymore even though they still have the bone inside their body.

2. Which of the following continents did marsupials begin from?

e. North America

3. Comparing a dragonfly, bird, bats - explain the type of evolution that these

organisms show.

Birds and bats' wings have the same structure, also known as homologous structures. Their wings have very similar structures because they inherited it from a common ancestor. However they are not completely the same because they "tweeked" their wings to enable different functions. On the other hand although birds bats and dragonflies all have wings and they look very similar, however the underlying structure of dragonflies' wings is completely different compared to those of birds and bats. That is because they evolved from different ancestral groups, yet they both evolved so that they have wings, that is called a convergent evolution.

4. Explain how the Common Descent Lab shows DNA evidence and ancestry as

evidence for evolution. Include examples of Primates.

In the common descent lab we took the hemoglobin strand of DNA of humans, chimpanzees, gorillas and their common ancestor and compared the similarities. We found out that humans and chimpanzees have the most in common and have the least in common with their common ancestor, that is because humans are the most evolved species out of the whole family. DNA evidence and ancestry serves as evidences for evolution because they allow us to compare the similarity(common sequences) of two different species, thus determining how closely related they are.

5. Explain homology using some examples from your readings.

Homology relates to similar structures in different species because of their common ancestry. However, gradually, the structure develops differently in different species because they have to have different functions. Examples would be that the structure of a human's is the same as the wings of birds, they both consist of 2 big bones linking to a bunch of small bones. And also humans' hands have the same structure as the front limbs of sea creatures like whales.

Evolution- Titaalik

We spent most of the class discussing and going over the book "Your Inner Fish" and talked about how humans and all other creatures share a common ancestor. And Neil Shubin decided to look for the intermediate creature between fish and reptiles.

We went to the museum and look at a real life model of the tiktaalik and we observed its differences and similarities with fish and in the end of the class took a quiz on this topic.

Unit Test 1

Today we had our first unit test on chapter 1, that covers everything that we have learnt so far.  That test was reasonably challenging since the free response had quite a lot of writing, however the multiple choice was decently handled I believed. I am looking forward to getting my test grades back!

All Chemistry

Today in class we did a review on all chemistry, about all the topics that were covered previously, including water, basic chemistry, macromolecules and isomers. The quiz was rather easy considering I got 1s on both parts. Also we have to complete our lab reports for next class since that is the most important assignment so far.

Macromolecules and Lab

Today in class, we went through the slides of macromolecules and isomers. We went through basic knowledge such as structural polymers, geometric polymers and how different isomers are formed. For basic structures and functions of macromolecules, we went through dehydration, hydrolysis, DNA, RNA and other basic informations.
For the second part of the class, we finished a lab, and the objective is to identify what is in 16 different substances, whether its protein, starch, glucose and lipid or any combinations of these substances. We use different tests to test the existence of these substances including biuret, benedicts, sudan III and iodine.

House Case

In the beginning of the class, we went through basic concepts of the cell membrane:

We learnt why water and how water goes through a cell, through the protein channels, since the lipid fat layers will repel water away.

For the second half of the class, we did a house case diagnosis on a high school senior runner with symptoms of vomit, headache, cramps etc. Me, Anthony and Blake volunteered to be the three "main doctors" and we had to put the clients' symptoms, tests that we think we should perform, and our hypothesized diagnosis on the board. After our class has asked for the meal history, vitals, medical history and performing some tests on the high school senior. I came up with the conclusion that he is over hydrated, or diagnosed Hypertremia due to different factors, such as his urine having too little amount of Na in it. A detailed lab report will soon be uploaded for this house case, and I will go over the details of the diagnosis. 

After learning about diffusion and osmosis, today inclass we went onto the topic of rate of diffusion, as explained below:

Rate of Diffusion

Since the average kinectic enerygy of different types of molecules (different masses) which are at thermal equilibrium is the same, then their average velocities are different. Their average diffusion rate is expected to depend upon that average velocity, which gives a relative diffusion rate

where the constant K depends upon geometric factors including the area across which the diffusion is occuring. The relative diffusion rate for two different molecular species is then given by
Reference : http://hyperphysics.phy-astr.gsu.edu/hbase/kinetic/diffus.html
We did a lab that was done the first time ever at Webb Schools of california, it was a lab to check the rate of diffusion of something and determine what is the best shape for a cell to acquire maximum performance on rate of diffusion. We were given three cubes of 3% agar-phenolphthalein in different sizes and also some NaOH solute, since phenolphthalein reacts with NaOH and when it does it turns pink, we can determine how fast did the rate of diffusion happened by using three cubes of different sizes and lengths to determine the best shape. So first, we put the blocks into the NaOH solution,

Then after 3 minutes we took the cubes out of the beakers and cut them in halves then measured them:

After the measurements, we realized that the smaller the cube is the faster the rate of diffusion and thus explaining why cell division happens. Because cells needs their nucleus to be in a reaction in order to react therefore having a smaller volume allows other chemicals to penetrate in the cell easier.

Diffusion/ Osmosis

Diffusion

Diffusion refers to a process which molecules intermingle because of their kinetic energy that goes in all directions. They tend to move from places with higher concentration of the molecule to lower concentrated area. It is defined by Pearson as the net movement of molecules down their concentration gradient.
e.g. perfume spreading across room

Osmosis

Osmosis is a special case of diffusion that only happens in water. Where there is a semi- permeable membrane once again from higher concentration to lower concentration. The picture below illustrates
an example:

For this class, we reviewed basic concepts of diffusion and osmosis, and went through key words such as water potential, molecular motion, hypertonic, hypotonic, isotonic etc. After, we started on 2 labs relating to osmosis. For our first lab, we put different solutes of various molarities into semi- permeable membrane and we massed and put them in a beaker with water outside of the membrane. After 30 minutes,  we massed them again and determined the mass change thus allowing us to know the molarity of each of the solutes.
Link of results: https://docs.google.com/spreadsheet/ccc?key=0AvnnOJLj_iJAdFZQSlo0QjdONVBRQ2ZMcExvSVdkZEE#gid=0

After, we started our second lab and we soaked the potatoes inside the solutes this time and the results will be determined and posted soon.

Dihydrogen Monoxide

Water is essential to all living things and it is imperative for us to have a true understanding of this substance. In class, we went through different problems relating to water and explained why water is so simple yet is so vital for life and interesting.

Interesting facts
- Water covers 70% of Earth's surface
- Only 3% of water on Earth's surface is freshwater

Properties of Water:
-Cohesive behavior
- Expansion as freezing
- Versatility as solvent
- Moderate temperature

Water Cycle:
-Evaporation: Liquid water changes into water vapor
-Sublimation: Snow or ice turning directly into water vapor
- Transpiration: Liquid given off by plants evaporating
- Condensation: Water vapor turning into liquid water
- Precipitation: Water in clouds drop to Earth's surface


















Cohesion/ Adhesion

- Water molecules forms hydrogen bonds with other water molecules / surface

Expansion as freezing

- Water = bent structure (120 degrees)
- When frozen = forms crystalline structure (more space) = expansion

Moderate Temperature

- Water takes 30 times more energy to heat than gold
- Able to break and recreate hydrogen bonds quickly
- Ability to insulate (Ice above water = keep water warm)

Solvent

- Molecules with different polarities
- Water molecules comes
- Hydrogen bonds surround the molecule
- Forms hydration cell



How plants transfer water form roots to leaves?
- Water goes through Xylem
- Uses both adhesion and cohesion
- Adhesion = water sticking onto the xylems
- Cohesion = water sticking to water itself
Video:
http://www.phschool.com/science/biology_place/labbench/lab9/images/xylem.gif

Basic Chemistry.... In Preparation for Biology

Biology is the study of living things, and all living things are made out of atom. Therefore for us to understand. Biology, we must first grasp basic concepts of chemistry. From having the knowledge of atoms to how chemical bonds together.

Important Terms

Elements: matter combined with same atoms with same proton numbers

Compound: mixture of elements

Atom: "the undivisible", smallest division of anything

Proton: part of the nucleus of an atom, with a positive +1 charge and weighing 1 Dalton

Neutron: other part of the nucleus of an atom, with no charge, also weighing 1 Dalton

Electron: particles that surround the nucleus, with a negative -1 charge, with a negligible weight

Isotope: When an atom has different number of neutrons-

Atoms

Atoms are the basic material of everything, and it can be divided into 3 sub-atomic particles: protons, electrons, and neutrons. Below is a diagram of the carbon atom

As seen in the diagram, electrons are found on the outer energy level of the nucleus while protons and neutrons are found inside the nucleus.

Particle	Location	Relative mass	Charge
Proton	Nucleus	1	+1
Neutron	Nucleus	1	0
Electron	Outside the nucleus	1/1840	-1

Electrons are arranged according to their energy level. This is called the electronic structure orelectronic configuration of the atom. Shown Below:



 

Elements 

Elements are substances made out of atoms with the same number of protons. They are the most basic substance. 

Each element has its own:

• name and chemical symbol
• characteristic physical properties, e.g. density, electrical conductivity, melting point and boiling point
• characteristic chemical properties, e.g. reactions with water, oxygen, acids and other chemical

Different number of neutrons = an isotope

Different number of electrons = an ion

Different number of protons = different element

Compounds

Compounds are formed by combining elements through chemical reactions. However, elements can only bond according to the number of valence electrons they have, and they always try to to get 8 valence electrons, aka the octet rule.

Usually you would try to derive the empirical formula from the molecular formula. The empirical formula is the same thing as the molecular formula except you take the L.C.M of the formula and simplify it. In other words, the molecular formula gives you exact number of atoms while empirical formula only gives you the ratio. Example Problem:

Chemical Bonds

Chemical bonds are something that atoms form with each other when combining with each other. There are 2 kinds of chemical bonds, the Ionic Bond, and the Molecular Bond (Covelant Bond).

Ionic Bonds

Electrons are transferred in ionic bonds. Ionic bonds form when metals bond with non metals. Salts are examples. Like other ionic compounds, many salts are soluble in water. In water, the giant 3-D lattice breaks up into ions which move around relatively freely in solution. Each ion is surrounded by a cluster of water molecules (we say they are hydrated). This can be shown by an equation:

NaCl (s) + aq    Na⁺ (aq) and Cl^- (aq)

Covalent Bonds (Molecular Bonds)

Electrons are transferred in covelant bonds. Covalent bonds form when when non metals bond with non metals. 

Reference: http://www.rsc.org/Education/Teachers/Resources/cfb/basicchemistry.htm

http://www.universetoday.com/82128/parts-of-an-atom/

http://preparatorychemistry.com/images/molecular_formula_trioxane_.gif

For our second class of honors biology, we went through some worksheets of basic chemistry, in preparation for our topic on biochemistry. The above information gives a general idea of what I learnt/ reviewed in the class. In addition to that, we reviewed on how to correctly draw lewis-dot structures for ionic bonds and covelant bonds respectively.