Monday, May 28, 2012

Invertebrate Comparison

Invertebrate: Some examples of invertebrates are insects and flatworms. They are small and slow moving and have no backbone. Some physical characteristics are that they are multicellular, they have no cell walls, they reproduce sexually and they are heterotrophic.
Vertebrate: Some examples of vertebrates are parrots, humans, snakes etc. They are animals with a internal skeleton made of bone. They have a well developed internal skeleton, a highly developed brain, they have a advanced nervous system and they attain a outer covering of protective cellular skin. They are also classified into 5 groups: fish, amphibians, reptiles, birds, and mammals.


Genome Entry 6 : Sex

The genetic diseases Prader-Willi syndrome and Angelman's syndrome are both cause by the same lack of chromosome 15. It has been shown that whether a child inherits either syndrome it depends on the parent from whom the mutation was inherited. In this situation Prader-Willi is from the father and Angelman's from the mother. It relates to how the placenta is controlled by paternal genes and how it uses the mother's body and resources. In genetic cloning like Dolly, it seems to erase all genetic imprints so that the organism will survive. Imprinting has a effect on the brain as well. The mother's genes controls the development of the cerebral cortex while the father controls the development of the hypothalamus. With this we inherit the mother's way of thinking and the father's innate moods. Gender roles in behavior have been controlled in the genome rather than by the environment.

Genome Entry 5 : Instinct

Many great theories implied that genetic determinism of human instinct is much more probable. Human grammar is probably the best example. Young children can speak with perfect grammar before even learning it. On chromosome 7 there is a gene that is linked to the disorder called Specific Language Impairment or SLI.  In a study of a English family with a history of the disorder, Myrna Gopnik proposed that SLI does not develop from the physical act of speaking but rather in the ability to learn grammar rules. Individuals that have SLI communicate with much larger vocabulary because of the lack of internalized grammar which is similar to adults trying to learn a new foreign language. Ridley also connects grammar instincts to natural selection and how it is used for survival.

Genome Entry 4 : Environment

In this chapter, Ridley shows that genetic inheritance is also based on the environment of the individual. Chromosome 5 holds the asthma gene. This disorder holds a direct relationship with allergies. Many theories support why asthma has been increasing. theories such as new pollution from new technologies and even excessive hygiene. While studying the asthma gene, it was found that the closest genes to the asthma causing gene are the two genes that produce immunoglobulin-E. This protein comes in different forms and it helps with the release of histamine into the body. Even though asthma has been linked to genes, the individual genes are based on ethnicity and the cause of the disease is mostly determined by the environment of the individual.

Tuesday, May 22, 2012

Genome Entry 3 : Fate

In this chapter Ridley begins by identifying genes by the diseases that they can cause to the different organs and even to the ways of suffering in order to show the difference between a gene and a mutation. In the Wolf-Hirschhorn gene, those who attain this gene are healthy and those who don't have the Wolf-Hirschhorn syndrome and those who have the mutation have Huntington's chorea. In 1970, Nancy Wexler, her father and her doctor decided to research the gene because she knew that she might carry the gene. It was finally found in 1993. The number of repetitions  of CAG signifies at what age the carrier will exhibit the symptoms. The number of repetitions increase over time especially in sperm production but not in the cerebellum. Ridley then talks about how people handle fate by testing positive for Huntington's and how it is not always the best thing to diagnose a disease that can not be cured.

Genome Entry 2 : Life

In this chapter of the Genome book, Ridley begins by speaking about the history of life. He believes that life began with RNA instead of DNA. He claims that RNA is more chemically active and automatic than DNA. Prehistoric "ribo-organisms" eventually made up DNA from a evolutionary error and trial process because it was much faster and more reliable. Next, he discusses the Last Universal Common Ancestor or LUCA. It has been believed that LUCA is a sort of bacteria living in a hot marine environment. Bacteria attain their genetic inheritance by stealing the genes from one another. Now LUCA is believed to be more of a protozoan because the bacteria would have dropped the RNA so that it could reproduce faster. Doing that it would help them in evolutionary strength. In the end, Ridley states that life is physical history and it isn't a genealogical one. The history of life can only be found in the genome.

Saturday, May 12, 2012

BOW Nephron


Nephron is the basic structural and functional unit of the kidney. Its main function is to regulate the concentration of water and soluble substances by filtering the blood and reabsorbing what it needs and excreting what it doesn't need.In depth, the nephron regulates blood volume/pressure, controls the levels of electrolytes and metabolites and regulates blood pH. Its functions are regulated by hormones and the endocrine system.
There are two classes of nephrons, They are cortical and juxtamedullary nephrons. they are classified according to their length and the Loop of Henle and the location of the renal corpuscle. The Loop of Henle is a part of the nephron that leads from the proximal tubule to the distal convoluted tubule.

Loop of Henle: 




BOW 3 STARFISH

Starfish are also known as sea stars. They are echinoderms that belong to the class, Asteroidea.There are about 1,800 living species of starfish. They are among the most familiar out of the marine animals and they have mamy characteristics including regeneration and feeding on mussels. They come in many sizes and they have many different feeding methods. Starfish are opportunistic feeders meaning that they have certain feeding behaviors such as suspension feeding and specialized predation on certain prey.

Starfish have a water vascular system that aids them in locomotion. This system has many features such as tube feet in the ventral faces of the starfish's arms helping them with movement and helping them eat. The mouth of the starfish is located on the underside of their bodies and it leads to their cardiac stomach and then to the pyloric stomach. Starfish also have a very complex nervous system. The esophagus is surrounded by a central nerve ring which sends radial nerves to each arm. All of these connect to form the brain. The ring nerves and radial nerves help coordinate the balance and direction for the starfish.

picture links:

http://www.google.com/imgres?um=1&hl=en&sa=N&biw=1280&bih=843&tbm=isch&tbnid=0_dbmbiE_wzO5M:&imgrefurl=http://universe-review.ca/R10-33-anatomy.htm&docid=5Z6HQJVvjv14TM&imgurl=http://universe-review.ca/I10-82-starfish.jpg&w=650&h=423&ei=B0SvT9m2NIHgiALt_tmcBA&zoom=1&iact=rc&dur=135&sig=112205966848938297682&page=1&tbnh=122&tbnw=187&start=0&ndsp=21&ved=1t:429,r:1,s:0,i:129&tx=99&ty=94

 dissection link:
http://www.youtube.com/watch?v=ZJ7BzlZ5QW4