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What is involved in cell division of animal cells?

Cellular mitosis in animals follows several steps: interphase, prophase, metaphase, anaphase, telophase and cytokinesis.Interphase - the cell prepares for division during this "resting" cycle; during this period DNA may begin to replicate but chromosomes are not visibleProphase - chromatin begins to condense into chromosomes; centrioles form and move to opposite ends of the cell; the nuclear membrane dissolves and the mitotic spindle begins to formMetaphase - spindle fibers begin to align the chromosomes towards the center or equator of the cell, pairing them to ensure the equal division of ch..

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Who invented the 24-hour clock?

Beginning in the 15th century BCE, the Egyptians designed water clocks for more precise timekeeping. Different water clocks were used for different seasons to keep up with the varying seasonal hours. The classical Greeks and Romans also used the 24-hour system with hours of varying length, and this usage continued until the 14th century AD in Europe with the invention of mechanical timekeeping. A system of hours of equal length was proposed by the Greek Hipparchus in the second century BCE but was only used for calculations.

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How was nitrogen named?

The most significant use of nitrogen is for the creation of ammonia; it comprises about 78 percent of the atmosphere of the Earth, with about 4 quadrillion tons of nitrogen floating in the air. Processors use fractional distillation to extract nitrogen from liquefied air.\nAs a gas, nitrogen is mostly inert and is used in protective applications within soldering, welding and facilitating the manufacture of semiconductors. Liquid nitrogen has applications in performing experiments at extremely low temperatures, preserving biological samples and refrigerating a number of items.

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What is smaller than an atom?

Just as atoms can be combined to create different types of matter, subatomic particles are used to create different types of atoms. Protons and neutrons make up the nucleus of atoms, and it is the different combinations and configurations of these subatomic particles that are responsible for providing different types of atoms with various properties. Protons, neutrons and heavier particles, known as hadrons, are created from even smaller subatomic particles, known as quarks.

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Which organisms are most closely related?

The classification of organisms according to common ancestry is known as cladistics. Cladistics is one of the ways of examining taxonomy, or the classification of organisms. It uses several tools to classify organisms, including comparison of genetics, proteins and physical traits. Because it classifies organisms into what are known as clades based on their most recent common ancestry, cladistics can lead to some surprising classifications.\nFor instance, while salmon and lungfish would commonly be thought of as closer relatives than lungfish and cows, scientists think that the lineages of lun..

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What does ISS stand for?

The operation of the International Space Station builds on the experience gained from Mir, launched by the Soviet Union, and Skylab, a United States project. It is positioned in low Earth orbit, where it is easier to reach than higher orbits but high enough to research the affects of microgravity on humans and other organisms. Its relative isolation from the atmosphere has aided a number of research fields, including exploring the nature of dark matter.

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For what is acrylic plastic used?

Acrylic plastic belongs to a group of polymers known as poly(methyl methacrylate) or PMMA. PMMA is a clear plastic found in molding sugar or casting syrup form. The plastic is resilient and clear making it perfect for automobiles, ocular equipment and other glass substitute industries. In cars, it is used to cover external lights as well as being a safer alternative to glass. PMMA is also popular in ocular applications such as contact lens manufacture.Lighting fixtures also make use of PMMA as it is slow burning or self-extinguishing and does not produce harmful gas in the presence of a flame...

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Why is fracking bad for the environment?

Fracking is a technique used in the industry to increase production of oil and natural gas. This method involves boring deep into the ground and creating a well, which is typically encased in cement or steel. Highly pressurized fluids travel down the well and are then injected into cracks in shale or other compact formations. The fluids include vast amounts of water, a fracking solution, sand and various chemicals. Fracking causes the formation of larger fissures in the rocks, triggering the release of oil and natural gas.Extracted natural gas contains a significant amount of methane, which is..

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Is ethanol polar or non-polar?

Polar bonds create polar molecules. Polar bonds occur when two covalently bonded atoms unevenly share their electrons. This, in turn, results in an uneven distribution of the molecule's electrical charge, which means that at any given time, parts of that molecule carry a weak-positive or weak-negative charge. These weak-positive and weak-negative charges attract polar substances to one another, so polar substances can dissolve other polar substances. They also exclude non-polar substances, such as oils. A rudimentary but effective test for polarity is to see whether a substance dissolves ..

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How does the small intestine aid in the absorption process?

The small intestine consists of three parts, explains the International Foundation for Functional Gastrointestinal Disorders. Those parts are the duodenum, jejunum and the ileum. Each part of the small intestine digests and absorbs specific nutrients.\nFood, liquid and digestive juices, collectively known as chyme, first enter the duodenum from the stomach, states the IFFGD. A potent mixture of enzymes, bile salts and bicarbonate from the liver, pancreas and the intestinal walls themselves breaks down carbohydrates, fats and fat soluble vitamins. The bicarbonate also neutralizes the stomach ac..

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