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What is the average human arm span?

The arm span of the average human not only differs by gender, but it also differs largely by country, as well as time period. People are statistically becoming taller in time, thus developing larger arm spans, which is known as the secular trend of human growth.

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What can disrupt cellular respiration?

Metabolic poisons include compounds containing cyanide, insecticides such as rotenone and antibiotics such as antimycin. These compounds disrupt cellular respiration by interfering with mitochondrial activity and preventing ATP production. Without the energy provided by ATP, the cell dies.\nAnoxia, or the absence of oxygen within a cell, also disrupts cellular respiration. Scientists classify the causes of anoxia as pulmonary or circulatory. Pulmonary causes include suffocation, drowning and trauma to the lungs. Circulatory causes include heart attacks, atherosclerosis and tourniquets. Other c..

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What is the definition of nonionic surfactants?

As a wetting agent, nonionic surfactants are often mixed in with potting media in order to ensure easy water absorption into plant soil. UGA has also indicated that research is being carried out into nonionic surfactants' efficacy as antifungal treatment. In addition to application in the horticultural sector, nonionic surfactants can be used, like other surfactants, to create cleaning projects such as detergents. The substance's ability to break water's surface tension is also useful in this application as it allows cleaning water to absorb grease, which is normally repelled fr..

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Why does wood float on water?

Wood is made of individual fibers, and there is some space in between these fibers. Because of this, most woods will naturally float. Woods with denser fibers and those with little space between fibers, however, will sink. In addition, some wood will float until it is saturated with water, at which point it also will sink. Dense wood can still be used for making boats because the air inside of the boat lowers its total displacement.

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Why is DNA replication important?

DNA is generally tightly packed into a structure called chromatin. It is double stranded and twisted into a structure called a double helix. In order to replicate, DNA must unwind. After unwinding, each side of DNA separates by unzipping down the middle, with the two unzipped strands serving as templates for creating new strands. At the end of replication, the two new segments of DNA each contain one old and one new strand.\nReplication occurs at different rates in different types of cells. Some cells continuously divide and must constantly replicate their DNA. Other cells divide at a much slo..

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What is the chemical formula for magnesium iodide?

Magnesium iodide, also referred to as magnesium diiodide, appears as a brown-black powder and is often used in the Baylis-Hillman reaction. This salt has a water solubility value of 1480 grams per liter and is incompatible with air and moisture. To avoid decomposition, this compound must be stored in tightly sealed containers and kept away from excess humidity. Magnesium iodide leads to potentially dangerous reactions when inhaled or ingested. Some of the most common symptoms of prolonged exposure to magnesium iodide include headache, skin rashes and redness.

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How many blood types are there?

Blood types are inherited characteristics and are determined by the genes carried on chromosome 9 of humans. The red blood cells in blood carry identifying factors called antigens on their surfaces. People with blood type A carry A antigens on their red blood cells, type B carries B antigens, type AB carries both antigens and type O carries neither. Blood plasma, the watery part of blood, contains antibodies that attack specific blood cell antigens. Type A blood carries anti-B antibodies, B blood carries anti-A, AB carries neither and O carries both.\nType AB blood is labeled the universal rec..

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What is a contaminant in microbiology?

One of the most common microbiological contaminants is the Escherichia coli bacteria, or E. coli. Certain varieties of E. coli exist naturally in the body, but the strain known as E. coli O157:H7 causes severe vomiting, diarrhea and abdominal cramps. Infections from E. coli O157:H7 occur from consuming contaminated food or water. Microbiological infections must be treated immediately with antibiotics or antiviral medications. Failure to do so can result in life-threatening conditions, such as kidney failure and liver damage.

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What are starches broken down into?

Starches are most commonly found in grains and breads and are an abundant source of energy for the body. The process of breaking down starches in the body begins in the mouth. Saliva, along with chewing, literally breaks the food down into small pieces that are able to be processed easily by the stomach. Saliva also contains enzymes that begin breaking down starches on a cellular level, converting them into maltose.\nMaltose is a carbohydrate that is more easily processed by the body. Once the food is swallowed and passed into the stomach, various acids and enzymes go to work on deconstructing..

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What is the chemical formula for quartz?

Quartz exists as a continuous framework of atoms arranged in a tetrahedral tessellation. In this tessellation, one silicon atom is bonded to four oxygen atoms, while one oxygen atom is bonded to two silicon atoms. This means that the repeating unit of the crystal structure only contains one silicon atom and two oxygen atoms, giving the chemical formula SiO2.

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