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What was your favorite topic this semester? Why?
My favorite topic this semester is actually genetics and reading the Genome book.  I really like genetics and the book just open my eyes up to the human genome.  I think reading about the different part of the human chromosome and how one gene can change a phenotype of the human body is so interesting.  I guess the genetics part is really interesting because it also ties in with chemistry, another subject of interest.

What was your least favorite?
I think my least favorite is learning about invertebrates.  For some reason, particularly the invertebrates.  I found the structure and function of those invertebrates hard to grasp.  Overall, I am just really bad at anatomy.

What would you change about this class if you could?
If I can change one thing about this class, I would say for labs that take over an hour (a whole period) do them online.  Because when an experiment is stopped and then continued, there is always a larger percent error in the data, plus online labs teach all the concepts and allow the students to perform an experiment with no error.  It is a great way to teach concepts, without having to do an experiment that may fail under a traditional condition.

What do you feel is your biggest accomplishment in biology this year?
My biggest accomplishment is that I spend a whole day looking at stuff around my house and on my street and start to identify them with biology.  For example, I would identify plants as monocot/dicot, and what phylum it belongs to on the streets.  I also use concepts learned in biology to reason with my peers.

Genome 10th Entry: Immortality

Again, this chapter deals with cancer.  In 1972, James Watson discovered that polymerases do not start copying DNA at the tip of the chromosome, instead, they start coding the DNA part way so a bit of the telomere is left off.  Telomerase, a protein, is responsible for increasing the continuous divisions of cells.  Cancer cells switch the gene on when it should be off, allowing the cells to replicate nonstop.  In this chapter, Ridley linked cancer with age, as people get older, they are more prone to cancer because the decrease in accuracy in cell division.  

Genome 9th Entry: Death

Ridley explores cell death and cancer.  He introduces the idea that cells reproduce themselves when they are not supposed to.  On chromosome 17, a gene called TP53 is responsible for suppressing cancer cells, also called a tumor-suppressor gene.  In contrast, the oncogenes encourage cell growth.  Oncogenes can cause cancer when they are switched on and tumor-suppressor genes cause cancer when they are switched off.  Ridley explains that various types of cancers may be caused by mutations of the TP53.  In cancerous cells, the protein for TP53, p53 stop working properly, and stop signalling apoptosis or programmed cell death.       

Genome 8th Entry: Self-Interest

Ridley describes in this chapter that how some genes, even through evolution, cause more harm than benefit.  An example would be reverse transcriptase.  It serves basically no purpose in the genome, rather, virus, such as the HIV(which is harmful to the human body) need it to function.  Reverse transcriptase exists in the human body because retroviruses placed themselves there and to survive, they reproduce.  Like reverse transcriptase, many junk DNA in the human genome, only consider about themselves, functioning on behalf of their own benefit, instead of the human's.  35% of the human genome is consist of junk genes.  Ridley believes that from this aspect, revolution is not only about the competition between species, but also a competition between genes that organisms use as their hosts.  However, even if we use more energy to duplicate these junk genes, junk DNA help create an unique set of DNA in DNA fingerprinting.

Genome 7th Entry: Instinct

Ridley begins this chapter introducing many distinct political ideals, such as Marxism and Freudianism.  Ridley implies that genetic may have a heavy determination on human behavior.  Using the example of human grammar and how little children can speak perfect grammar before learning it, indicating that it might be innate.  A gene on Chromosome 7 linked with a disorder called SLI (Specific Language Impairment) unlock the idea that heredity has do to with speech as well.  Because the discovery of a gene that can affect grammar, Ridley connects grammar instincts to natural selection as a means of survival.  

Sem 2 Week 6 Compare and Contrast of 3 Invertebrates

Sea cucumber
Kingdom: Animalia
Phylum: Echinodermata
Class: Holothuroidea



Sea cucumber, picture: http://library.thinkquest.org/J001418/media/seacuc.JPG



Cuttlefish
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda



Cuttlefish, picture: http://a-z-animals.com/media/animals/images/470x370/cuttlefish3.jpg



Crayfish
Kingdom: Animalia
Phylum: Arthropoda
Class: Crustacea



crayfish, picture: http://www.biol.andrews.edu/everglades/organisms/invertebrates/arthropods/pond_crayfish/pond_crayfish_main.jpg


Similarities:
- All three invertebrates live in an aquatic environment.
-All three invertebrates have some form of defense mechanism against predators.
- All three invertebrates are able to move around, not attached to the ocean floor or rock like a polyp.

Differences:
- The crayfish is hard shell (has an exoskeleton).
- The sea cucumber has a layer of spiny skin, used for protection.
- The cuttlefish has tentacles for locomotion and feeding.