We were working in this pig dissection all week. We were divided up into 3 groups.
Group 1 was talking about the external and digestive systems. So basically most of the outer parts that you can see with your eyes then we had to open the pig to look at the digestive system.
Group 2 was talking about circulatory and respiratory systems. These systems contained the heart and the lungs and the pieces of the heart and so on.
Group 3 was talking about execratory and reproductive systems. Like the kidneys and the cortex and the ureter and so on.
After all of the groups studied their pigs we went walking around to everyones stations and we were all explaining to one another what our system was and all the major parts in it. Then after we did a test where we had to name all the pig with all three groups. When we did this i scored a 82% on my pig test. I knew most of the parts on it.
Monday, May 20, 2013
Changes in population
1. How do the authors of this page define microevolution?
A-Microevolution is evolution on a small scale—within a single population. That means narrowing focus to one branch of the tree of life.
2. How do they define a population?
A-It is a group of organisms that interbreed with each other and they all share a gene pool.
3. Summarize each of the 4 mechanisms of microevolutionary change that are discussed.
A-Mutation; Is when some “green genes” randomly mutated to “brown genes”.
Migration; Beetles with brown genes immigrated from another population, or some beetles carrying green genes emigrated.
Genetic drift; When the beetles reproduced, randomly more brown genes than green genes ended up in the offspring.
Natural selection; The green gene beetles get easily eaten then the brown beetles. The brown beetles go to the next generation.
4. Summarize the 3 examples of microevolution on this page
A-The Size of the Sparrow;
The differences are genetically based, they almost certainly represent microevolutionary change: populations descended from the same ancestral population have different gene frequencies.
Coping with Global Warming;
There is many human-induced changes in the environment, Mosquito populations have evolved so that slightly shorter days are required as a cue for going dormant.
Building Resistance;
The enterococci bacteria, have evolved a resistance to several kinds of antibiotics
5. Summarize the results of the two different experiments (with and without predators).
A-The course gravel with the predator present then fewer than 15 generations of sections the spots got darker and blended it in. The fine gravel with the predator present then fewer than the 15 generations of sections, the spots got lighter and blended in with its surroundings. The course gravel with no predator changed and the fishes had dark spots even though it had a light surrounding and the fine gravel with no predator had light spots when it has a dark background.
6. What types of selection were demonstrated in each experiment? Are these experiments truly cases of artificial selection? Explain your answer.
A-The types of selection is artificial selection because it is the domestication of plants and animals. They are using artificial selection because they are manipulate the spots on guppies.
7. Pick your three favorite questions from the quiz and write how you would answer them if you were teaching this class.
A-"What is the big deal about artificial selection?"
How I would answer this is by saying that artificial selection is an interesting miniature model of what has happened in the evolution of life on Earth.”
"How can gene frequency change?
A-Humans have the same number of genes but frequency genes are the number of different sorts of gene variants in a population. So it might start of with the coding for green eyes, then the next time it will be brown eyes.
"How can microevolution happen?"
A-Microevolution can result from mutation, a spontaneous change in DNA; or migration, genes coming into the population from elsewhere; or genetic drift, random selection for a particular gene.
Use the simulation to test different hypotheses about why some guppies are very brightly colored even though that makes them easy for predators to find.
1. Why do some guppies tend to be drabber than others?
A-The guppies are on different parts in the same stream.
2.Why do some guppies tend to be more colorful?
A-In different stream locations.
3
.What role does color play in guppy survival?
A-They blend in so their predators don't find them.
4. Explain the push and pull that the environment (including predators) has on the coloration of guppies in Endler’s pools.
A-Predators influence the evalution of a population of guppies, but it takes generations of time.
EXPLORING THE ROOTS OF EVOLUTIONARY THEORY
Awareness of biological evolution emerged over centuries through the cumulative observations of many naturalists, biogeographers, comparative anatomists, and paleontologists. When Darwin and Wallace in the mid-1800s arrived at the idea of evolution by natural selection, they had been influenced not only by their own travels and observations, but also by the writings of many of their predecessors. Darwin's ideas were also influenced by his travels as a young naturalist on the H.M.S. Beagle. The islands he explored off the coast of Ecuador, the Galapagos, are hotbeds of evolutionary change. However, as you will see, Darwin did not entirely recognize the importance of these islands until after he returned from his voyage.
Activity
In this activity you will access the evolution section of the University of California's Museum of Paleontology to explore some of the roots of evolutionary biology. You will then visit the Why Files site to learn about Darwin's voyage to the Galapagos and the current state of these islands.
Part 1.
Use your browser to go to the "History of Evolutionary Thought" exhibit at the University of California Berkeley Museum of Paleontology at http://www.ucmp.berkeley.edu/history/evothought.html
Use the links in this section to learn about and briefly describe the background and scientific contribution of each of the following people:
1. Erasmus Darwin
was a respected physician, a well known poet, philosopher, botanist, and naturalist.
2. Jean Baptiste Lamarck was famous for his discredited theory of heredity, the "inheritance of acquired traits." He also was a zoologist and as a forerunner of evolution.
3. Georges Cuvier found vertebrate paleontology as a scientific discipline and created the comparative method of organism biology. He contributed an immense amount of research in vertebrate and invertebrate zoology and paleontology, and also wrote and lectured on the history of science.
4. Thomas Malthushad observed that nature plants and animals produce far more offspring than can survive. His view is that there were natural outcomes of population growth and food supply was not popular among social reformers who believed that with proper social structures.
Part 2.
Use your browser to go to the Why Files' "Treasures of Evolution Island" at http://whyfiles.org/125galapagos/index.html
Use the information from Sections 3 and 4 to answer the following questions:
1. What interesting evidence of geological change did Darwin observe while visiting the Galapagos?
A-He had learned that species change in response to the environment as the losers are culled and the winners have more young which perpetuate those winning characteristics. a rich assemblage of related species had arrived -- or developed -- after the islands emerged from the ocean.2. What did Darwin learn about the Galapagos finches when he returned to England? What vital information had he neglected to record when he collected them?
3. Describe the distribution pattern of Galapagos mockingbirds. What question did this raise in Darwin's mind?
A-"Darwin wanted to know, why do you have four different species, when one species certainly seems good for all the islands." The pattern is that three islands each housed one species, and one species lived on all the other islands.
DNA Fingerprint Web quest
Activity
In this exercise, you will learn the basics of DNA fingerprinting and consider the use of DNA in criminal investigations.
Part 1.
Use your browser to go to NOVA’s web site about “Killers Trail,” the story behind the man who inspired the Fugitive TV series and later the movie version starring Harrison Ford:
Click on the “Chronology of a Murder” section and read about the events that led up to the murder trial of Dr. Sam Sheppard.
- In your opinion, what role (if any) did newspaper stories and editorials have in the outcome of the original trial of Dr. Sam Sheppard?
In my opinion I think that some people are stretching the truth about this and they are leaving facts out because they think he is guilty. But then there are some people that are thinking that Marilyn Sheppard needs justice and who is going to speak for her. It did say that on July 1989 Richard Eberling, an interior decorator and the former window washer at the Sheppard home, is convicted of aggravated murder in the death of Ethel May Durkin. But at the beginning it says that window washing company employee Vern Lund leaves town. Both guys are window washers at the Sheppards home and one guy had be convicted of murder and when they found Marilyn dead the other man left too.
Go back to the Killers Trail homepage and select ”Create a DNA Fingerprint.”
Read about the crime and the suspects then go on to part 2. Answer the following questions about the technique as you go through the simulation:
- What is the function of the restriction enzymes in DNA fingerprinting?
A-It cuts along different locations. The lengths of the fragments will vary from person to person because the code for every person’s DNA is different. Some of the fragments will be long, others will be short.
- What is the function of the agarose gel electrophoresis step?
A-The agarose gel is thick, porous, Jell-O-like substance. It will act as a molecular strainer, allowing smaller pieces of DNA to move through more easily than larger pieces.
- Why is a nylon membrane used to blot the DNA?
A-You do that because you just added probes to the nylon membrane, and what they do is attach themselves to DNA fragments on the nylon membrane.
- What does a dark spot on the X-ray film indicate?
A-The probes are now present at only a few locations on the membrane, exposing corresponding areas on the X-ray film.
Part 2.
Use your browser to go to Frontline's "What Jennifer Saw" at
The material on this site is about a man convicted of rape but later exonerated by DNA evidence. To read a summary of the case, choose the link to Ronald Cotton's wrongful conviction, then choose "Summary of Cotton's Case."
In the interviews section, read the interviews with DNA expert Peter Neufeld and lawyer Barry Scheck.
Answer the following questions:
- What evidence was initially used to convict Cotton?
A-A photo identification was made by one of the victims, then a police lineup identification wa made by one of the victims. A flashlight in Cotton’s home resembles the one used by the assailant. Then the rubber from Cotton’s tennis shoe was consistent with rubber found at one of the crime scenes.
- What did the DNA evidence show?A-The DNA evidence shows that the samples from one victim were too deteriorated to e conclusive, but the samples from the other victim’s vagainal swab and underwear were submitted to PCR testing and showed no match to Cotton.
- How could DNA fingerprinting be used to prevent a false conviction if a case like this was being tried today?A- DNA fingerprinting can be used to prevent a false conviction by the fact that there is a poor innocent person dropped their gloves on the floor and a criminal picks them up and commits a crime in those gloves then there is more of a chance of the criminal getting away with it because it would have the poor innocent persons DNA.
- What percentage of convicts are unjustly convicted of sexual assault cases?A- 28%
- The O.J. Simpson trial was one of the most visible trials that attempted to use DNA evidence. In the end, the DNA evidence was not satisfying to the jury, who acquitted Simpson. What do Neufeld and Scheck believe about the impact of the O.J. Simpson trial on the use of DNA evidence?A- They review cases of people who say that they have been falsely convicted and arrange for DNA test that may claim of innocence.
Bacteria Lab
In this virtual lab you will assume the role of a lab technician in a modern molecular biology laboratory. As such, you are responsible for providing lab results to medical doctors for use in diagnosing their patients. Be sure to follow the steps of the procedure in order and to make use of the notes on the right side of the computer screen. As you work through the lab, answer the following questions:
1. As the medical technician in charge of this investigation, what are you trying to determine about the tissue sample provided to you?
A-About the tissue sample is to identify a bacterial sample received from a clinician.
2. How did you prepare the DNA to be used in this investigation?
A-Well first the DNA consists of dissolving the cell wall with a digestive buffer, and what the buffer contains proteolytic enzymes that technically eat the cell wall. This will take about several hours. Then the DNA is contained in supernantant (the liquid) then transfred to the PCR tube.
3. Describe how PCR is used to make copies of DNA sequences. Use the animation and notebook entries in the PCR Amplification step to guide your answer. Note that you may replay the animation as needed.
A-PCR is used to make copies of DNA sequences by the fact you first start off by adding PCR Master Mix solution to the sample of DNA. You then prepare negative and positive control reactions. It is then put into a machine, and it determines the temp, the time, the cycle number, melt, anneal, and extend. The first step is to melt so it can separate the two DNA chains in the double helix by heating the vial containing the PCR reaction mixture to 95 degrees celcus for 30 seconds. Then the vial is cooled to 60 degrees celcus. At that temperature the primers will bind (anneal) to the single strand of DNA. The last step (extend) is to let the DNA extend the copy of DNA strand by rising the temp. to 70 degrees celcus for 45 seconds. When you do these three steps each is carried out in the same vial, then at the end of a cycle, each piece of DNA in the vial has been duplicated.
4. Summarize the technique used to purify the PCR product.
A-The technique that is used to purify the PCR product is the PCR Master Mix solution. What it is, water; a buffer to keep the mixture at the correct pH for the PCR reaction; large quantities of the four nucleotides adenine, cytosine, guanine, and thymine; large quantities of oligonucleotide DNA primers that bind the 16S rDNA region to indicate the replication process. What it does is basicly you mix the product with DNA mix it in the machine let it set and it makes copies of DNA.
5. What is produced during the sequencing prep PCR run? Use the animation and notebook as needed in thinking through your answer.
A-The is produced during the sequencing prep PCR run is when the DNA replication starts. You have to melt, anneal, and extend.
6. Describe how the automatic sequencer determines the sequences of the PCR products.
A-When it is in the machine it determines the temperature, the time remaining, cycle number, melt, anneal, and extend.
7. What does BLAST stand for?
A-BLAST stands for Basic Local Alignment Search Tool
8. What conclusions did you make using the results of the BLAST search? Did these conclusions support a clinical diagnosis for the patient (what disease did they have)?
A-What BLAST does is it will start with the reference of the search program, which is the number of letters in the sequence and then the number of letters in the database. Then a graphic representation of the sequence matches, and a list of matches. There are a lot of sequences in the database and some of them are from the same species and therefore might be similar.
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