Notes Survival of the Sickest Chapter 6 / PGLO Lab

• 18th century - Edward Jenner  discovers how vaccines work b/c he notices milkmaids who get cowpox don't get small pox --> infects teens with cowpox and they don't get small pox as well 
• all humans start as one cell - less than 3% of our DNA is used to create/build cells, the rest are useless 
• useless/junk DNA isn't used to make proteins, but does cause evolution, mostly b/c of viruses
• evolution caused in part by adapting to viruses/bacteria
• genetic changes b/c errors when DNA goes from parent --> daughter cell
• other mutations can be caused by radiation
• antigenic drift- when a mutation occurs in the DNA of a virus
• antigenic shift- when a mutation acquires new genes from a related strain
• mutations = random, occur during reproduction & --> natural selection
• Jean-Baptise Lamarck- theory of inherited acquired traits
• Barbara McClintock- geneticist,"jumping gene" intentional mutations in DNA to respond to unusual events
• genes jump when under stress
• antibodies = against specific viruses and bacteria and once you have them, you always do (why vaccines work)
• retroviruses- made of RNA, turn themselves from RNA into DNA and "rewrite" the DNA, off spring inherit the retrovirus through their parents' DNA
• if the virus does't hurt,  becomes a part of the gene pool (HERVs)

Class Today:

Today in class we began our pGLO lab. We created +pGLO and -pGLO (+ having plasmid). After getting the plasmid inside the pGLO using a heat shock, we put broth into each in order to feed the bacteria. We then put +pGLO into two petri plates, one with broth and ampicillin and the other with broth, ampicillin and ara (a type of sugar). Next we put -pGLO into two petri plates as well, one with only broth and one with broth and ampicillin. We predicted that +pGLO with amp and LB would grow, because the plasmid is resistant to the amp, and it might glow. We predicted the same for +pGLO with LB, amp and ara. For -pGLO with LB and amp we predicted that it would neither grow nor glow because the ampicillin would kill of the bacteria. And for -pGLO with just LB we predicted that it would grow but not glow.

Quiz and Class Today

1. Explain the significance of Mendel.
     Mendel's experiments in the 1850s and 60s demonstrated that traits passed on from parents may not be visible in the child, however they can still be visible in their grandchildren. This shows that the variant can be passed on, but not be seen. This led to the discovery of physical DNA.

 2. Draw the structure of DNA and who created this structure.
Watson and Crick made this discovery.

3. Explain each of the five examples of variations that occur to DNA and give an example of each. 

     1. Point mutation. This is when a single pair in the DNA changes. This can have an overwhelming affect on the individual's whose DNA has this mutation. For example, in whippet dogs, one mutation can lead to an individual losing the gene that signals the body to stop gaining muscle, which leads to huge whippet dogs.
     2. Insertion.  of new base pairs can lead to variations in DNA as well. For example, 800-base pairs can be inserted into a pea to create wrinkled peas as opposed to smooth peas by changing its sugar and water content.
     3. Gene Copy Number. This is when genes are duplicated because during cell division, errors are copied. This can lead to both differences between individuals within a species, or to differences between species. Chimpanzees contain one gene for the starch digesting enzyme, whereas in humans it was duplicated so much that it led to humans having 10 copies of the gene.

     4. Duplication. This is an error in copying, commonly in species whose DNA has the same base pair eight or more times in a row. The base pair is commonly copied too many times or too few. One example is of pigs, who commonly have a base pair copied two too many times, leading to light colored pigs lacking pigmination.

     5. Regulatory Changes. These are changes in DNA that affect when and where genes are activated. This can cause severe and extreme effects such as changing body parts durning an organisms development. This is what caused changes from the very bushy teostine and the modern tall and lean cornstalk.

4. What is evo-devo? 

     A specialty within evolutionary biology that focuses on and examines the affects of important gene changes, and how those effect evolution.

5. Make a connection between human migration and the mutation of lactose intolerance.
     As humans spread out around the world, they developed different diets based on what resources were available to them. Mutations in humans to be lactose tolerant would thrive and pass down their genes to their children in areas where lactose was a large part of their diet, and this group would evolve to have a lot of people that are lactose tolerant. However, in areas with little to no lactose, this mutation would not affect their survival, and many would remain lactose intolerant.

IN CLASS:

Today in class we began constructing DNA structures with our partners. We cut out different nitrogen bases and created hydrogen bonds between each matching pair and created  phosphodiester bonds in order to complete our double helix strand of DNA.

Geneticist Video Part 2

     Today we finished the geneticist video. Alrighty.

Article/Video Response

The Journey of Man video and the Traces of a Distant Past have both taught me many things I did not know. I learned that the earliest humans existed 200,000 years ago in Africa. All people that are alive or have ever lived have been related, and are descendants of the first “mitochondrial eve.” I also learned the migratory path of Africans. This migration began 50,000 years ago, first going from Africa to Australia, and eventually spreading out into every corner of the World, the last place that was reached being South America. One of the major questions that was being asked by many geneticists and researchers is how they originally got from Africa to Australia, by land or by sea. Most of the research I have done supports the slow movement to Australia along the coast of Asia. Another common question was why they moved, curiosity because of their large, intelligent brains, or simply the need for more food and more resources. Back to the original migration, I knew nothing about how DNA could tell us this, but I learned it was through looking at mutations. These mutations act as a guide showing that people from all over the world, have the mutation of the Sanbushman. When a small group moved to Australia, their DNA continued to mutate and have markers, which are not currently present in Africans. This pattern continues and makes the journey of man very clear through DNA, even without the supporting fossil evidence. I also learned that when geneticists are testing DNA, they typically use male DNA, because male transmitted DNA has tens of millions of nucleotides, while mitochondrial only has 16,000 nucleotides. Another aspect of early human life that was mentioned in both my article and in the movie was the humans’ interaction with Neanderthals. It discussed how little to no inbreeding took place, which I found very interesting.  The movie and the articles I have read were all very interesting, and taught me a lot about human evolution in particular, and also connected back to general evolution about mutations and adaptions in genes.

Geneticist Video

Today in class we began by getting our test back and discussing the questions we missed so we can correct them on Blue Harvest. After this we discussed in groups of four what we read for homework, which was a National Geographic Article talking about evidence that all humans came from Africa and spread to different countries, and also talked about how genetics proves this as well as fossils because DNA shows that the genetic variety in Africa is about twice as high as everywhere else because they have been there the longest. After this we watched a movie about roughly the same topic. The movie starred a geneticist who wants to physically travel the route of ancient man, because despite the proof in genetics, it still seems impossible for early man to have made that trek in such a short period of time. The geneticist began in Africa with a tribe believed to be the direct descendants of the earliest humans. These tribe members have never left their area, however they have features similar to those of Asians, Europeans, and Africans. It was a really interesting movie to watch and we will be finishing it next class.

Unit 2 Test

We took a test. Yay. I got a 95%. Yay.

Standard 9!!!

Hardy-Weinberg Quiz
#2 

Question: After graduation, you and 19 friends build a raft, sail to a deserted island, and start a new population, totally isolated form the world. Two of your friends carry (that is, are heterozygous for) the recessive cf allele, which in homozygotes causes cystic fibrosis/ Assuming that the frequency of this allele does not change as the population grows, what will be the instance of cystic fibrosis on your island.

Known information:
20 people on island - so there are 40 alleles
2 are heterozygous - 2 recessive alleles in group 
p + q = 1

p² + 2pq + q² = 1

Calculations:

2 alleles / 40 alleles = q

q = .05 frequency

People who have cystic fibrosis must have two recessive alleles, or q² because the gene is recessive and only appears in those with two recessive alleles. Therefore, q² = .05² = .0025, or 0.25%

Evolution by Natural Selection Quiz
#15

Question: Do you think that evolution by natural selection is occurring in this cactus population? Explain why or why not.

Answer: Yes, the right cactus survived and will be able to produce because of its mutation, spikes, that will then be passed on to its offspring. The left cactus, however, did not have this mutation, which made it more vulnerable to being eaten by an animal. Because it was eaten, it will not be able to reproduce and have offspring. Therefore, there will be more cacti with spikes and less without spikes.

Quiz  #1B Basic Chemistry
#4

Question: What is the maximum number of covalent bonds an element with atomic number 8 can make with Hydrogen?

Answer: Two Covalent Bonds.

Explanation: The element Hydrogen has two electrons, therefore both remain in its outer layer. An element with an atomic number of eight would have eight electrons, 2 in its inner shell, and six in its outer shell. The octet rule states that every element wants to have eight electrons in its outermost shell, in order to be most stable. Therefore, an element with an atomic number of eight will want to have two covalent bonds to fill its outermost shell and become stable.

Honors Biology Unit 1 Test
#9 

Question: What is the reason why hydrocarbons are not soluble in water?

Answer: The majority of their bonds are non-polar covalent carbon to hydrogen linkages.

Explanation: Water's polarity works to break down substances by using its positive side to attract the positive side of other polar molecules, and its negative side to attract the negative side of other polar molecules. However, because hydrocarbons are not polar, the water cannot use this method to break it down because it cannot attract it.