Thursday, February 23, 2012
Describe how a nephron works.
By filtering out everything in the blood, except for large proteins and blood itself. Then the distal and proximal tubule will slowly bring back in what the body needs, like calcium, chloride, etc and whatever is left goes to the ureter and gets to the bladder to be urinated out. The nephron capsule filters urea, water, glucose, and salts from the capillary, and sends them through the tubule. The tubule re-absorbs water and glucose back into the blood, and carries what is left over (urine, a mixture of urea, water, and salts) to the ureter. Nephron is the basic unit of Kidney, it has basically three parts: Glomerular capsule, Henle's loop, and Collection tube. Collection of nephron plays an important role in the excretory system.
Monday, February 20, 2012
Starfish
Starfish are often a pest of commercial clam and oyster beds, a single Starfish my eat over a dozen oysters or young clams every day. The body wall of echinoderms consists of three layers. The outer layer is only a single layer of cells which covers the entire animal including its various spines. The third layer is also a single layer of cells the main difference being that these cells are ciliated. This layer encloses the the animal's coelom separating the animals guts from its skin. The middle layer is much thicker and is called the dermis. It is composed of connective tissue and contains the exoskeleton. The exoskeleton supports the spines, warts and tubercles that are often found on the echinoderm surface.
Apart from its skin/spine, an echinoderm also has contact with the external world through its water vascular system and the tube feet that are a part of this system. The water vascular system of the echinoderms is unique in the living world and easily distinguishes them from all other phyla. The water vascular system starts with an opening to the external environment called a madreporite. From this a short straight canal called the stone canal leads to the ring canal. The ring canal is a ring as might be expected and it has five longitudinal canals branching off from it into each of the arms.
Echinoderms are either filter feeders, substrate eaters or carnivores. The gut is U-shaped in the Crinoidea with the mouth and anus being on the same surface. Echinoderms have a sub-epidermal nerve net running all over their body. As well as this they have a circum-oral nerve ring with 5 radial nerve cords extending from it into the arms. Many Echinoderms use their tube feet as organs for gaseous exchange, but others such as the Ophiuroidea and the Holothuroidea have additional special sites or organs of respiration.
Ophiocistioidea
Astroidea
Echinoiudea
Holothuoidea
Apart from its skin/spine, an echinoderm also has contact with the external world through its water vascular system and the tube feet that are a part of this system. The water vascular system of the echinoderms is unique in the living world and easily distinguishes them from all other phyla. The water vascular system starts with an opening to the external environment called a madreporite. From this a short straight canal called the stone canal leads to the ring canal. The ring canal is a ring as might be expected and it has five longitudinal canals branching off from it into each of the arms.
Echinoderms are either filter feeders, substrate eaters or carnivores. The gut is U-shaped in the Crinoidea with the mouth and anus being on the same surface. Echinoderms have a sub-epidermal nerve net running all over their body. As well as this they have a circum-oral nerve ring with 5 radial nerve cords extending from it into the arms. Many Echinoderms use their tube feet as organs for gaseous exchange, but others such as the Ophiuroidea and the Holothuroidea have additional special sites or organs of respiration.
Crinoidea
Images from Google
Thursday, February 16, 2012
Genome Entries 3
Chapter 6: Intelligence
Ridley introduces the search for the intelligence gene. He comes to the conclusion that intelligence genes do not work in a vacuum. Studies done on separated twins have shown that there is, in fact, heritability to intelligence and personality, and that there was zero correlation between IQ scores of adopted children living in the same family. Ridley also introduces the concept that the intelligence genes are indeed more expressive later in life rather than less expressive because people begin to choose their own environments and comfort zones, giving more liberty to the genes to express themselves. This is proven by the fact that elementary school children in Head Start programs are no longer ahead of their peers by the end of elementary school.
Citation:
Ridley, Matt. Genome: The Autobiography of a Species in 23 Chapters. New York: HarperCollins, 1999. Print.
Citation:
Ridley, Matt. Genome: The Autobiography of a Species in 23 Chapters. New York: HarperCollins, 1999. Print.
Monday, February 6, 2012
Double Fertilization
It is the process at the time of fertilization when two male gametes are brought to the oval sac one of them fuses with egg cell to form embryo and the other gamete fuses with the cells in the center that are called polar nuclie to form endosperm further to provide nourishment to the growing embryo. A single pollen grain has 2 sperm. Double fertilization occurs when 1 of these sperm combines with the egg, and the other sperm combines with a cell (endosperm). That is in order for the seed to keep being produced. Seed has to be germinated, and without the extra sperm (double fertilization) the plant couldn't germinate and would go extinct. The union in flowering plants of two sperm nuclei. One sperm nucleus unites with the egg to form the diploid zygote, from which the embryo develops, and the other unites with two polar nuclei to form the triploid, primary endosperm nucleus.
Genome Entries 2
Chapter 3: Fate
Ridley uses the example of the Wolf-Hirschhorn gene, where individuals with the gene are healthy, those without the gene have Wolf-Hirschhorn syndrome, and those with a mutated version have Huntington’s chorea. In 1970, a woman named Nancy Wexler and her father knowing that she may carry the mutation for Huntington’s chorea, decided to search for the gene. The gene was finally found in 1993 and it solely a repetition of the codon CAG. Excess CAG repeats have been found to induce at least five other neurological disorders and at least twelve known human diseases. The number of repetitions can increase over time, except in the cerebellum, but especially in sperm production. Ridley then goes on to discuss how people handle the fate of testing positive for a genetic test for Huntington’s, and how it is not always wise to diagnose a disease that cannot be cured before its onset.
Ridley uses the example of the Wolf-Hirschhorn gene, where individuals with the gene are healthy, those without the gene have Wolf-Hirschhorn syndrome, and those with a mutated version have Huntington’s chorea. In 1970, a woman named Nancy Wexler and her father knowing that she may carry the mutation for Huntington’s chorea, decided to search for the gene. The gene was finally found in 1993 and it solely a repetition of the codon CAG. Excess CAG repeats have been found to induce at least five other neurological disorders and at least twelve known human diseases. The number of repetitions can increase over time, except in the cerebellum, but especially in sperm production. Ridley then goes on to discuss how people handle the fate of testing positive for a genetic test for Huntington’s, and how it is not always wise to diagnose a disease that cannot be cured before its onset.
Citation:
Ridley, Matt. Genome: The Autobiography of a Species in 23 Chapters. New York: HarperCollins, 1999. Print.
Ridley, Matt. Genome: The Autobiography of a Species in 23 Chapters. New York: HarperCollins, 1999. Print.
Sunday, February 5, 2012
Extra Credit Blog
What topics really confused you?
Some of the topics that confused me including the Bacteria/Viruses and Fungi chapters. I really can't remember all the parts and structures of a bacteria and a virus. Viruses are more complex in structure and function compare to a bacteria, and this is why viruses are even harder to remember. It is really confusing since there are many kinds of bacteria and viruses in this world.
What topics do you feel very clear on?
I feel very clear on the cells and plants chapters. This is because I've learned the basics of the cell back in freshman year when I was taking Biology. Therefore, with that knowledge added to what I'm learning in Biology AP makes it so much easier and more understandable for me. On top of that, I have an interest in plants and how plants works so this is why I feel comfortable and understands a lot when it comes to the plants chapter.
What lab/ activity was your favorite? Why?
My favorite lab/activities in the class was lit. circle, the review game that we played with foods as reward, and the plants collection where we have to go outside and take pictures of 10 plants and 10 insects. Lit. circle allow me to discuss important and interesting topics with my group and sometimes with Ms. Malonek where I learned even more "interesting" things. I like how our discussions went really off topic sometimes but we still learn. I love doing the plants collection activity because it allows us to go explore around campus and find interesting insects and plants that I don't even know it exits in our campus.
What lab/activity was your least favorite? Why?
The lab/activity that was my least favorite is the staining dyes lab and labs where we have to use the microscpes. I don't like it when i accidentally spill the dye on my hands that won't come off until a few days later or when it gets messy in the class. Also when doing microscope labs, we always run out of time to look at our pants/species under the microscope so this gets confusing because we don't have the results.
If you could change something about the class to make it better, for instance the type of homework (not the amount) what would it be and why?
Some of the topics that confused me including the Bacteria/Viruses and Fungi chapters. I really can't remember all the parts and structures of a bacteria and a virus. Viruses are more complex in structure and function compare to a bacteria, and this is why viruses are even harder to remember. It is really confusing since there are many kinds of bacteria and viruses in this world.
What topics do you feel very clear on?
I feel very clear on the cells and plants chapters. This is because I've learned the basics of the cell back in freshman year when I was taking Biology. Therefore, with that knowledge added to what I'm learning in Biology AP makes it so much easier and more understandable for me. On top of that, I have an interest in plants and how plants works so this is why I feel comfortable and understands a lot when it comes to the plants chapter.
What lab/ activity was your favorite? Why?
My favorite lab/activities in the class was lit. circle, the review game that we played with foods as reward, and the plants collection where we have to go outside and take pictures of 10 plants and 10 insects. Lit. circle allow me to discuss important and interesting topics with my group and sometimes with Ms. Malonek where I learned even more "interesting" things. I like how our discussions went really off topic sometimes but we still learn. I love doing the plants collection activity because it allows us to go explore around campus and find interesting insects and plants that I don't even know it exits in our campus.
What lab/activity was your least favorite? Why?
The lab/activity that was my least favorite is the staining dyes lab and labs where we have to use the microscpes. I don't like it when i accidentally spill the dye on my hands that won't come off until a few days later or when it gets messy in the class. Also when doing microscope labs, we always run out of time to look at our pants/species under the microscope so this gets confusing because we don't have the results.
If you could change something about the class to make it better, for instance the type of homework (not the amount) what would it be and why?
Sometimes it gets really confusing about what assignments we are suppose to do and what we are suppose to have in our notebook and lab notebook. It will clear things up a lot if there is a list of what needs to be in our notebook on your blog maybe a few days before notebooks are due. And also I think simulations are taking a lot of time to complete because sometimes it gets hard and we don't know what to do. Also it will be helpful if you can tell us what chapters we need to complete instead of saying like "cell chapters" because i don't know how many cell chapters are there. I would also want more class lectures with the powerpoint because I learn more when you teach like that and have less labs so more time for us to read the chapters and review your class powerpoint lectures.
Semester 2: BOW 1 Genome Entries 1
Chapter 16: Memory
Ridley introduces the problem of knowledge versus instinct, and learning versus heritability, but then asserts that natural selection will make universal common knowledge like grammar instinct but will leave things like vocabulary to be learned so that it can change with time. Eric Kandel isolated a chemical called cyclic AMP that is involved in the process of learning by changing itself when something is learned. It has also been shown without a doubt that humans are not the only creatures capable of learning. Bees, mice, and even sea slugs can learn, as proven by Kandel’s study and many others. However, while the human brain is capable of immense amounts of learning, the brain is created and ultimately controlled by genes and related proteins and chemicals.
Citation:
Ridley, Matt. Genome: The Autobiography of a Species in 23 Chapters. New York: HarperCollins, 1999. Print.
Citation:
Ridley, Matt. Genome: The Autobiography of a Species in 23 Chapters. New York: HarperCollins, 1999. Print.
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