Wednesday, May 23, 2012

I'm still researching on genetics, for it is going to be the main focus on our end of the year exam. I have been going through power points and have found this to be the most important parts of this unit. 


Mitosis is a type of reproduction where a cell produces an identical replica of itself with the same number of patterns of genes and chromosomes.


Meiosis is a special process in a cellular division where cells are created containing genes that are of different types of combinations with different chromosomes from the normal cell. It is used in sexual reproduction of organisms to combine male and female,  to create a new organism. Mitosis is used by one cell organism to reproduce.


http://www.slideshare.net/cmillica/what-you-need-to-know-for-the-genetics-test


After researching on genetics I took a genetics quiz. It was a fun way to test my knowledge. I could see how much this 20% project helped my science grade increase, and will help me in10th grade, for I will be more knowledgeable about this subject.

Quiz: http://www.rcs.k12.va.us/csjh/woody/chapter3_science.htm
This is an example of the questions I had to answer.


Tuesday, May 22, 2012

Genetics

Genetics is the next thing we are going to learn in science class. Therefore, I am going to study it so I can understand it more in depth in class.

Everyone on the planet had genes. Genetics have been with us since the beginning of time. It has even been mentioned in the bible. Greeks always had theories about heredity and why children look like their parents. Gregory Mendel is the discoverer of the gene and the founder of genetics.

In his spare time, Mendel bred pea plants in the monastery gardens. Many pea plants had many different traits, like some were tall, some were short, some pease were smoth, others were wrinkly. Mendel then tried to make hybrids (copies). He did this by snipping the male part of the plants ot prevent selfing. Then he dusted the female part with the desired "Father". Then he tied bags over the flowers to prevent stray pollen from getting into the flowers. Thus, he was able to control the perentage of each generation. His first discovery was that tall plants corssed with short ones produced tall ones, not medium ones. He then concluded that some genes were dominant and some were recessive.http://library.thinkquest.org/3696/index2.htm


Genetics


The branch of biology that deals with heredity, especially the mechanisms of hereditary transmission and the variation of inherited characteristics among similar or related organisms.


Video comes from : http://www.youtube.com/watch?v=F4wHaORe9-c




This is a brief introduction to the topic of genetics and is a short documentary film. It talks about the history of genetics and the concepts that provide that foundational knowledge that today's research is built upon. It talks about Gregor Mendel and the concepts that provide the foundational knowledge that today's research is built upon. After being introduced to the fundamental ideas of genetics I can understand more what I'm reading about and the current techniques used to study genetics.



Gregor Mendel was a monk in Austria who raised peas in the monastery gardens. While breeding his peas, he made some big discoveries. They were discoveries about genetics
The peas had several traits he could see. Some plants were tall and some were short. Some had wrinkled pods and some had smooth pods. Some pods were green and some where yellow. The flowers were white or purple.
Mendel looked at each trait and learned how they were passed down to the offspring plants. Since plants breed using pollen, Mendel controlled which plants pollinated other plants. This was how he discovered many important genetic rules.
First he learned that some traits showed up more often and he called them dominant traits. The traits that showed up less often he called recessive.  He discovered that if tall plants and short plants bred, they made a mixed or hybrid offspring.
Hybrid plants are different from dominant plants even if they looked the same. Each gene has two chances at a trait - two copies or alleles. So a hybrid plant could be carrying the allele for a recessive trait even if you can't see it. So, for example, a hybrid plant might be tall like its dominant parent, but it still could have an allele for shortness that you don't see.
When two tall hybrid plants breed, one in four of the offspring are short. This is a 3:1 Mendel saw this and it is still taught in basic genetics classes today.

Friday, May 18, 2012

After studying photosynthesis and the immune system, I want to learn about genetics.


Before learning about genetics, I want to study the necessary vocabulary that we are going to use throughout this topic. According to different sites these are the most important ones:


  • Dominant — observed trait of an organism that mask the recessive form of a trait
  • Egg — haploid female sex cell produced by meiosis
  • Fertilization — fusion of male and female gametes
  • Gamete — male and female sex cells, sperm and eggs
  • Genetic recombination — major source of genetic variation among organisms caused by re-assortment or crossing over during meiosis
  • Genetics — branch of biology that studies heredity
  • Heredity — passing on of characteristics from parents to offspring
  • Homologous chromosome — paired chromosomes with genes fro the same traits arranged in the same order.
  • Homozygous — when there are two identical alleles for a trait
  • Meiosis — type of cell division where one body cell produces for gametes, each containing half the number of chromosomes in a parent’s body.
  • Recessive — trait of an organism that can be masked by the dominant form of a trait
  • Sperm — haploid male sex cells produced by meiosis
  • Trait — characteristic that is inherited; can be either dominant or recessive
  • Zygote — diploid cell formed when a sperm fertilizes an egg.




  • http://www.ric.edu/faculty/ptiskus/peas/Genetics%20Vocabulary.htm
    http://www.kumc.edu/gec/glossnew.html
    http://www.biology.arizona.edu/vocabulary/mendelian_genetics/mendelian_genetics.html

    Tuesday, May 15, 2012

    After reading about the immune system for a couple of days, I found out that plants also have an immune system.
    They do not have special defender cells to make them immune. They have to use innate immunity provided by the cells. If a pathogen enters the plant, the cell of the plant make antimicrobial products which help neutralize pathogens. Sometimes, the pathogens survive and it triggers a cell of death response. Which causes host cells at the infection to die. According to http://eprints.nottingham.ac.uk/575/1/07icaris_jamie.pdf, the antimicrobial products nee to be tightly controlled and plants have evolved intricate systems to do this.
    Plants possess systems that are unique among recognition systems in that they produce responses that are the converse of immune responses.


    Pathogens: An agent that causes disease, especially a living microorganism such as a bacterium or fungus.



    The Immune System - Diseases


    http://www.youtube.com/watch?v=HNP1EAYLhOs
    Natural Killer Cells are the most aggressive white cells in the immune system. They make up about 5% to 15% of the total lymphocyte circulating population. They target tumor cell and protect against a wide variety of infectious microbes. Natural Killer Cells are a very important factor in the fight against cancer. Immune Stimulation is the key to keeping the white blood cell count high and giving the Natural Killer Cells a chance to fight cancer and other diseases


    Immunity is the ability to “remember” foreign substance previously encountered and react again, promptly. There are two kinds of immunity: active immunity, when the body is stimulated to produce its own antibodies, and passive immunity, where the antibodies come from outside the person’s body. Active immunity is usually permanent, and can be induced due to actual illness or vaccination. Passive immunity is not permanent because the antibodies are introduced from outside the body, thus the B-cells never “learn” how to make them. Some examples of passive immunity include antibodies passed across the placenta and in milk from a mother to her baby, some travelers’ shots, and the Rhogam shots we we discussed earlier this quarter. Because antibodies are only protein, they don’t last very long and must be replaced if the immunity is to continue.


    After reading this paragraph from: http://biology.clc.uc.edu/courses/bio105/immune.htm. I understand that being immune to something means being protected against a certain disease. You are protected by it because your body remembers the type of disease you had, and therefore you are immune to it. There are two type of immunity: Active and passive. I remember my teacher telling me that you can be passive immune to something by breast feeding. Thats why mothers usually prefer it then bottled milk. Also, he told us that active immunity is gained by getting a disease. Therefore, if you have chickenpox, for example, you never have it again... Because your immune to it.




    Tuesday, May 8, 2012

    Immune System

    In science, we are now doing the Immune System. I'm going to study the basic definitions and how our cells, tissues and organs work together to defend the body against bacteria. I will learn what the immune system's job is and how it works.

    According to http://www.nobelprize.org/educational/medicine/immunity/immune-overview.html We are surrounded by billions of bacteria and viruses. And us, as human beings, are like a walking smorgasbord, offering nearly limitless resources that they can use for energy and reproduction.


    Before starting, I'm going to study the basic vocabulary we need to know for the unit.
    Necessary Vocabulary
    Immune systemsystem that has fights off invading pathogens and preventing spread of cancer
    Antigensa substance that stimulates an immune response
    Immunityresistance to a certain pathogen
    Lymph Nodesfilter lymph for bacteria and tumor cells
    Lymphatic systema series of one way vessels; carry intercellular fluid from tissues to bloodstream
    Macrophagea large white blood cell that engulfs pathogens and cellular debris
    Lymphfluid found in the lymphatic system

    Natural Killer Cellsa large white blood cell that attacks pathogen-infected cellsand cancer cells

    Pathogensan organism that causes disease

    Phagocytesa cell that engulfs large particles or whole cells

    Phagocytosisa process where a cell engulfs large particles or whole cells
    Tonsilslymphatic tissue near back of throat; traps and removes bacteria and pathogens
    Vaccinesolution containing a harmless version of a virus, bacterium or toxin that causes an immune response when introduced into the body.




    What Is the Immune System and What Does It Do?

    The immune system defends people against germs every day. In most cases, the immune system is good at keeping people healthy and preventing infections. But sometimes problems with the immune system can lead to illness and infection.
    The immune system is the body's defense against infectious organisms and other invaders. Through a series of steps called the immune response, the immune system attacks organisms and substances that invade our systems and cause disease. The immune system is made up of a network of cells, tissues, and organs that work together to protect the body.
    http://teenshealth.org/teen/your_body/body_basics/immune.html#