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What are some human physical features?

Some common human physical features include walking upright, larger brains and hair that covers the body. Humans are able to adopt a stance that lets them walk upright. This is an evolutionary adaptation that took place during millions of years.Compared to other animals, humans have large brains. Although they only account for 2 percent of the body's mass, they consume 25 percent of its energy.Humans feature a thin covering of hair across their bodies. When it gets cold, or when something surprises them, this hair stands on end. Goose bumps become visible when this happens.While there are..

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What is the difference between physical and chemical change?

Chemical changes occur during chemical reactions, and these changes are not reversible. Some of the chemical reactions produce heat, whereas others require heat for them to occur. When a chemical reaction takes place, the molecules are rearranged and the reaction is followed by a change in energy as new products are produced.\nIndicators that show that a chemical change has occurred include change of color, odor, temperature and composition. Other signs include formation of gases or precipitation, when heat is given off during the reaction and when change is impossible to reverse.\nPhysical ch..

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What is the chemical formula for glycerol?

Glycerol generally appears as a clear, colorless and syrupy liquid, but it can also appear in solid state when the temperature is lower than 17 degrees Celsius. Glycerol is an intermediate compound that plays an important part in the metabolism of carbohydrates. Glycerol is generally used as a solvent, sweetener and emollient in the pharmaceutical industry and is also used therapeutically for constipation relief and ophthalmic lubrication.

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What is the function of a thykaloid?

Thylakoids are made of an interconnected system of flattened, disc-like sacs. They tend to form stacked aggregates, called grana, which contain approximately 10 to 20 thylakoids each. They contain the electron-transport chain, the photosynthetic light-absorbing system and an ATP synthase enzyme. On the outside of the thylakoid membrane is the stroma, which is the large interior space of the chloroplast and contains enzymes that incorporate CO2 into sugars, ribosomes, RNA and DNA. The membrane of the thylakoids contains important protein complexes that carry out the light reactions of photosynt..

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What is a double helix as it applies to genetics?

The DNA molecule contained in the double helix consists of only four nucleotides, which are the "letters" of the genetic alphabet. The nucleotides, known as A, T, G and C in short, are the code that program a cell. Nucleotides' specific sequencing determines the message that a gene sends to a cell. The order of the letters affects the physical characteristics of an organism.\nThe structure of the double helix was discovered in 1953 by James Watson and Francis Crick. It's now understood that cells' structure and function are determined by the order of the nucleotides that form a ..

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What does half-life mean?

When Ernest Rutherford discovered the half-life principle in 1907, the term used was "half-life period." It was condensed to "half-life" in the early 1950s.\nEach radioisotope has its own half-life. The symbol for half-life is t with a subscript ½. The number of remaining radioactive isotope can be derived by using the formula: N(t) = N(0) x (0.5)^number of half-lives, where N(t) is the remaining amount of radioisotope, N(0) is the initial amount of radioisotope and the number of half-lives is the quotient of time and half-life.

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How long is the body preserved after embalming?

The Funeral Consumers Alliance reports that embalming provides no public health benefits and merely delays the inevitable decomposition. The rate of decomposition is dependant on the strength of the embalming chemicals used and the way the body is interred. Bodies in a sealed casket above ground decompose much faster than bodies buried in the cool earth. Embalming chemicals are highly toxic, and embalmers are required to wear protective equipment when handling the chemicals.

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What is the attraction of valence electrons for metal ions?

The amount of valence electrons that a metallic element donates is different depending on the group to which it belongs. For example, with the exception of hydrogen, which is a nonmetal, elements in Groups 1 and 2 have 1 and 2 valence electrons respectively available for donating. Transition metals, which are found in Groups 3 through 12, can have a wide range of oxidation states and donate different numbers of valence electrons depending on the conditions present and the elements with which they are interacting. There are certain patterns established, however, and many transition metals are c..

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What does protein in your urine mean?

Temporary elevated levels of urinary protein are not unusual and may occur in younger people during an illness or after exercise, according to the Mayo Clinic. Protein in the urine is also often one of the earliest signs of kidney damage due to diabetes.\nProtein in the urine can also occur with preeclampsia, a condition that only occurs during pregnancy, according to the American Pregnancy Association. Preeclampsia, also known as toxemia, can occur after the 20th week of pregnancy and is characterized by protein in the urine and high blood pressure. While there are a number of risk factors a..

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What is the chemical compound formed between lithium and sulfur?

Lithium is one of the most reactive metals, so the compound can easily be prepared by treating it with sulfur. This process is usually done in liquid anhydrous ammonia. Similar to pure lithium, lithium sulfide is also highly reactive. When exposed to air, the compound quickly hydrolyzes to form hydrogen sulfide, a gas with a distinctive rotten egg smell.\nResearch on the possibility of using lithium sulfide in batteries is important, as it has the potential to generate much more energy than standard lithium-ion batteries.

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