described for the first time in sea urchin eggs in 1876 by the German biologist Oscar Hertwig. It was described again in 1883‚ at the level of chromosomes‚ by the Belgian zoologist Edouard Van Beneden‚ in Ascaris worms’ eggs. The significance of meiosis for reproduction and inheritance‚ however‚ was described only in 1890 by German biologist August Weismann‚ who noted that two cell divisions were necessary to transform one diploid cell into four haploid cells if the number of chromosomes had to be maintained
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allow cell phones to be sold without pre-market testing. The rationale‚ known as the “low power exclusion‚” distinguished cell phones from dangerous microwave ovens based on the amount of power used to push the microwaves. At that time‚ the only health effect seen from microwaves involved high power strong enough to heat human tissue. The pressure worked‚ and cell phones were exempted from any type of regulatory oversight‚ an exemption that continues today. An eager public grabbed up the cell phones
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of that weight like the first one was 1.15g but ended up with .78g the 2nd 1.42g and the third .45 the lightest of our shells. Now it turns out that the reason why shells dissolved from the vinegar is that vinegar has 4% acetic acid. If you soak an egg shell in vinegar you start a chemical reaction that dissolves the calcium carbonate shell. The acetic acid reacts with the calcium carbonate in the eggshell and releases carbon dioxide gas that you see as bubbles on the shell.
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Whose life are you really leading? There are two kinds of peer pressure. The Positive kind‚ and the Negative kind. The positive kind of peer pressure is‚ being pressured or convinced to do a certain task that you may not have had the confidence to complete or to do yourself. Another kind of positive peer pressure is when friends convince you not to do something that may not have been in your best interest. Negative peer pressure is just what it sounds like—It is when Peers try to make you think
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Stem cells Nowadays‚ stem cells are the hottest topic in the medical field. More and more researches are performed to investigate these mystic cells. In order to go deeper into this topic and fully understand it‚ let’s first take a look at the stem cells themselves‚ their origins and characteristics which make them so unique and crucial for the medical field. Stem cells are very complex and complicated‚ and‚ that is why‚ it takes a lot amount of time to get to the bottom of their structure to be
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going against their peers‚ not giving into peer pressure saves teens from dropping out of educational institutions‚ and criminality and drug use. The term “peer” refers to people who are usually a part of an identical social group. The term "pressure" puts forwards that the process that influences people to do things that express the possibility of being resistant to‚ or may not in a different circumstance‚ choose to do. So usually the term “peer pressure” refers to public
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Egg Osmosis Lab The purpose of this lab was to demonstrate an example of a spontaneous reaction and its connection to metabolism; in this case it was osmosis. The procedures that we used to complete the experiment were taking five eggs that had been soaked in a sucrose solution and then placing each one in containers of sucrose that each had different levels of concentration. The mass of each egg was measured before being placed into the solutions and then every 10 minutes after until they had soaked
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The article “The Hunt for Golden Eggs” by Brooke Lea Foster discusses donating eggs to help couples have children. The article briefly summarized how helpful and useful egg donors are to IVF patients and how they are truly “heroes” to those who cannot use their own eggs and suffer from infertility issues. Conception was once an easy task‚ but since 1980‚ in vitro fertilization (IVF) gives a unique and additional option to allow couples to have children who are “half” their own regardless of infertility
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individuals to change their attitudes‚ values‚ or behaviors‚ called peer pressure (Wikipedia). It might give some positive effects to teenagers when they are pressured toward positive behaviors‚ such as volunteering for charity or excelling in academics or athletics by their peers. Yet‚ many cases in peer pressure affects negatively to teenagers’ personality. As said by Wall Mueller (founder and President of the Center for Parent/Youth Understanding)‚ “The ugly reality is that peer pressure reaches its
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NASA Egg Drop Competition Josh Bryant Purpose: The objective of the project was to build a structure capable of bringing the egg safely to the ground without harming or damaging the egg in as little material as possible. Equipment: One larger bottle One smaller bottle One red balloon One blue balloon Too much tape Procedure: The procedure to make the device was as simple as cutting two bottles in half so that you may then stretch the balloon
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