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  • Transportation Materials Through The Cell Rough Er
    440 words
    ANIMAL CELLS ANIMAL CELLS My cell is the animal cell It really depends on which cell you are talking about - different cells do different things. Such as skin cells. They form a barrier on the outside of the body which protects the organs and tissues inside. It stops them getting damaged by bumps and knocks and also prevents bacteria and viruses from getting into your body. The cells structure, contains the Cell Membrane keeping the cell together and controlling what substances go in and out, Cy...
  • Animal's Cell Into The Egg
    374 words
    In 1938, a German scientist, Hans Spemann theorized that organisms could be reproduced. His belief was that by transplanting the central element of one animal's cell into the egg of another animal, the animal supplying the cell could be reproduced or "cloned". Dr. Spemann believed that the central element or "nucleus" of a cell contained the genetic blueprint for the structure of an organism. In 1952, American scientists tested his theory by infusing the nucleus of a frog's embryo into a frog eg...
  • Nucleic Acid Of The Virus
    305 words
    Protists and Viruses flagellum is a whip like tail that helps organisms living in moist places tomoveThe characteristics of protists is they are eukaryotic organisms, they are one or many-celled but do not have the complex organization found in plants and animals, and some make there own food and other can't. Protists are plantlike, animal like and fungus like. A virus is a microscopic particles that make up either DNA or RNA core covered by a protein coat. Viruses are so small an elect rn micro...
  • Surface Cells Of The Animal Region
    842 words
    Mechanisms of Epiboly of ectoderm in the Xenopus Laevis embryo Introduction Epiboly is a movement of gastrulation in the amphibian embryo, whereby ectoderm al precursors expand to cover the entire embryo. This process occurs in the surface and deep layer cells in the animal and marginal regions. Three rounds of cell division occur in the deep cells, while they also rearrange to form fewer layers. Superficial cells elongate by cell division while flattening, which gives them greater surface area ...
  • Cell Membrane
    1,120 words
    SECTION 3.1 WHERE LIFE HAPPENS 1. Living things can be either uni-cellular (one cell) or multi cellular. A bacteria is one type of unicellular. 2. About 8000 of the smallest bacteria could fit inside one of your red blood cells. 3. The longest cells are the thin nerve cells found in large animals and they can be more than a meter long. 4. The cell with the greatest volume is an unfertilized ostrich egg 5. A cell's shape is related to its function. For example, a long nerve cell is long and it ca...
  • Use Of Animals In Some Cases
    2,835 words
    The search for alternative methods to animal testing is underway in many laboratories across the entire world. While success has been made, the research is far from over. These alternatives have been developed using the concept of the three R's. In 1959, William Russell and Rex Burch defined the principle of the three R's in the book Principles of Humane Experimental Technique. The three R's are reduction, refinement, and finally replacement (5). The first concept, reduction alternatives, covers...
  • Cloning Of Animals
    827 words
    The cloning of animals will be beneficial to human beings inthe near future. Experiments in cloning animals started in the early nine-teen-fifties. Over the next forty years, scientists were only able to clone animals from very young embryonic cells. When these scientists tried to use older cells for cloning, they did not get normal results. This led many scientists to believe that animals could not be cloned from adult cells. (Pennisi, 1997) However, this all changed in the Summer of 1995 with ...
  • T Cell If The Self Antigen
    3,538 words
    How does the body achieve the functional silencing of antigen reactive clones The central tenet of the immune system is the ability to recognise and remove non-self components without affecting self components. The T cells and B cells of the immune system express a vast repertoire of antigen receptors. It is thought that the germline TCR repertoire is composed of in the region of at least 109 different specificities. Considering the potential number of antigens that may be bound by these recepto...
  • Animal Cells Three Different Kinds Of Chromosomes
    348 words
    Different kinds of Animal chromosomes exist with very different parts. To start, in animal cells three different kinds of chromosomes can be seen. The first kind is the X chromosome, which is one of the sex-determining chromosomes. The other sex-determining chromosome is the Y chromosome. The rest of the chromosomes are referred to as autosomes. Two different kinds of animal cells exist, male and female, each of which has a different make up of chromosomes. For example, the male fruit fly has 3 ...
  • Cell Cultures And Animals
    594 words
    THEORY: Cell culture studies are significantly reducing the need for animal research. Cell cultures contain living cells that grow in laboratory dishes and that scientists call in-vitro (in glass) cells. These cultures grow in nutrients (growth factors) collectively referred to as medium. There are tens of thousands of cell types. They come from human volunteers, animals, bacteria and plants. Toxicologists often use cell cultures to study the effects of natural and artificial substances on the g...

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