How to make pencils? Background One of the oldest and most widely used writing utensils‚ the pencil originated in pre-historic times when chalky rocks and charred sticks were used to draw on surfaces as varied as animal hides and cave walls. The Greeks and Romans used flat pieces of lead to draw faint lines on papyrus‚ but it was not until the late 1400s that the earliest direct ancestor of today’s pencil was developed. About one hundred years later graphite‚ a common mineral occurring
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Recently‚ there has been a debate about rather or not laws that govern induced pluripotent stem (IPS) cells differ from those currently in place for human embryonic stem (ES) cells. An IPS cell is created artificially from skin‚ fat and fibroblasts by reprogramming patient ’s own cells. Scientists believe IPS cells to be a promising source for treating diseases. An ES cell is created by destroying an embryo. Other scientists think ES cells will also be a promising source because it is composed of
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Exploring Life 1) Slides 1 and 2: What is the main difference between physiological adaptation (as in sense‚ respond and adapt to the environment) and evolutionary adaptation? Evolutionary adaptation occurs over generations. Evolutionary adaptation does involve genetic change but it’s the change in traits as a result of genetic change that drives natural selection and evolutionary adaptation (just genetic change alone won’t drive evolutionary change). Physiological adaptation is an adjustment to
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She is part of the reason why science has made it to where it has. She is the reason doctors can make cures for diseases. She is the contributing factor to most of the discoveries made‚ In regards to health and research. She is Henrietta Lacks. Henrietta unfortunately had cervical cancer and upon going to the doctors in the 1950’s‚ cells from her tumor were sent for research without her consent; and unfortunately the credit/rights that her and her family deserves have been thrown in the air. Medical
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Wendy Lee’s Peeling Bananas It is not often that I have to read an article or essay several times before I can make an appropriate response. As I read Wendy Lee’s article‚ Peeling Bananas‚ I found myself side-tracked by my own thoughts and feelings of being an African American here in the United States. As I read and reread‚ there were several areas that seemed to jump out at me and make me want to respond - what was so important about being referred to like peeling a banana‚ what in my own upbringing
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Discovering Cells Directions: answer the following questions using complete sentences. Use pages 6C-13C of your textbook. 1. What are cells? 2. When was the first microscope invented? 3. What is a microscope? 4. What is the difference between a simple and compound microscope? 5. Who was one of the first people to observe cells? 6. What did Anton van Leeuwenhoek discover? 7. A Scanning Tunneling Microscope (STM)
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structure of a cell to is a car. The reason I choose to do a car is because it is very similar to the structure of a cell and because to me it was the most interesting choice to choose from. Another reason I choose to compare the cell to a car is because it seemed to be the easiest one for me to do as compared to a Hogwarts or a city. Doing a house or a prison would have also been fairly easy but they were already picked by the people at my table. That wars why I choose to compare the human cell to an automobile
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Should Your Child Have a Cell Phone? From My Secure Cyberspace Kids love mobile phones‚ but they need to learn how to use them responsibly. In recent years‚ mobile phones have become extremely popular with young people. More than half of American teenagers now own a cell phone‚ and this number is growing quickly. Also‚ the age at which kids are getting cell phones is dropping‚ and many elementary school-aged children now carry cell phones. This trend is even more marked in countries outside the
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roles of mitotic cell division‚ meiosis‚ and fertilization in the human life cycle. Mitosis allows for growth and repair from the fertilized egg to the adult. In reproductively mature individuals‚ meiosis creates gametes with half the genetic material. The male gamete then fertilizes the female gamete during sexual reproduction‚ forming a zygote with a full set of genetic material. 2. Why are both cell division and apoptosis necessary for the development of an organism? Cell division is needed
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a) Using a human cell of your choice‚ describe how organelles work together to make and secrete a protein (LO1. AC 1.1) An epithelial cell in the thyroid gland‚ called a thyrocyte forms spherical follicles that produce a protein called thyroglobulin. This is a globular protein that has a functional role in metabolism. The protein is used by the thyroid gland to produce thyroid hormones; thyroxine (T4) is an example of one of the hormones created. Thyroxine is formed by iodine binding to tyrosine
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