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How does meiosis work?

During meiosis I:Prophase IStarting with a diploid cell, homologous chromosomes cross over genetic material. It is thanks to this that gametes achieve genetic diversity. The nuclear envelope then dissolves, allowing the centrioles to move towards the cell's pole and eventually attach to the chromosome's centromeres.Metaphase IChromosome pairs align.Anaphase IChromosomes move to opposite sides of the cell to reach the spindle fibers.Telophase IThe cell's microtubules separate, allowing the cell to divide and form two more cells.During meiosis II:Prophase IIThe nucleoli and nuclea..

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Why is NaCl soluble in water?

Positive and negative ions attract when NaCl, or salt crystal, is placed in water. However, negative chloride ions on the surface become attracted to positive sodium ions nearby and the positive sodium ions become attracted to the chloride ions and to the partially negative oxygen atom in the water. Soon a "tug-of-war" will occur between the other ions in the crystal and water molecules for the various positive and negative ions. This leads to the breakdown of the salt and to its ultimate dissolved self.\nOnce a salt has completely dissolved, the ions are fully released from the crystals and a..

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How does water move during osmosis?

Osmosis is movement of water across a semi-permeable membrane. In the case of biology, it is a cell membrane. Osmosis takes place when solutions have different concentrations of a solute. Solution is a solvent, in this case water, with an addition of a solute or any substance that can be dissolved in water. Sugar and salt are examples of a solute. If two solutions have equal concentrations of a solute, they are called isotonic and osmosis does not occur.The movement of water towards a hypertonic solution can be demonstrated if plant cells are placed in a concentrated sugar or salt solution. Th..

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Who invented radar?

In 1936, a prototype radar was demonstrated in New York City and detected aircraft from up to 7 miles away. After witnessing the demonstration, the Secretary of War ordered the prototype to be fully developed, and Congress offered $250,000 as funds for its development. The U.S. Army deployed the first fully developed model in 1941 in Hawaii. On Dec. 7, 1941, at 7:02 a.m., the recently installed radar detected aircraft north of its position, and the information was sent to the aircraft warning center. However, the information was misinterpreted as friendly bombers, and 46 minutes later, Pearl H..

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How does salt affect seed germination?

Salts are chemical compounds that are usually white and crystalline in structure. Common salts include sulfates, carbonates, chlorides, as well as nitrates of magnesium, calcium, potassium and sodium. Salts are typically used as fertilizer ingredients.When fertilizers are applied to soil, the salt content can accumulate. Increased salinity levels may result to poor plant growth, leading to a reduction in size of the plant's leaves, fruits, branches, roots and various other parts. Yield capacity also decreases with increasing soil salinity.

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Why is the thermosphere so hot?

Temperatures within the thermosphere increase at higher levels until it becomes somewhat stable up to the thermopause, the end of the thermosphere and the beginning of the exosphere. In upper levels, the typical temperatures of the thermosphere are usually anywhere between 900 degrees and 3,600 degrees Fahrenheit. This temperature often is about 400 degrees Fahrenheit hotter during the day than at night. It is around 900 degrees Fahrenheit hotter when the sun is very active than when it is inactive.\nThe thermosphere is considered part of the atmosphere, but it is extremely thin and has differ..

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How do you make smoke bombs without potassium nitrate?[DIFFICULT]?

First, cut the cold pack open and throw away the packet of water. Pour the leftover ammonium nitrate granules into a bucket or large pan. Next, turn the ammonium nitrate into a solution so the newspaper can absorb it. Do this by adding just enough water to the ammonium nitrate so that it dissolves the granules. If too much water is added, the result may be less smoke.\nDip a sheet of newspaper into the ammonium nitrate solution, and let it absorb the liquid for about 30 seconds. Carefully fold the newspaper to make it easier to handle, and then lay it out flat to dry. Once it is dry, secure th..

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What causes dirty water?

The most common waterborne diseases include cholera, which is caused by bacterial infections and induces severe attacks of diarrhea, often leading to dehydration. Arsenicosis causes painful skin trauma. Trachoma is also caused by a lack of adequate water supply and unsafe sanitation conditions. Malaria is caused by parasites which are carried by a certain type of mosquito, and typhoid fever can be caused by consuming contaminated water.

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Where can you find zinc?

About half of all the zinc produced is used for galvanizing or coating iron or steel to prevent rust. Zinc is alloyed with copper to make brass and with other metals to make alloys used in electrical systems, household fixtures and automobiles. Zinc is also used as a white pigment in paints and is an ingredient in fire retardants, rubber, skin ointments, lasers and dietary supplements.

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How many valence electrons does silver have?

Silver is a solid at room temperature. It melts at 1,763.2 degrees Fahrenheit. Its density is 10.49 grams per cubic centimeter. It is soft, malleable and ductile. The atomic weight of silver is 107.8682 grams per mole or atomic mass units. It is the most reflective metal with the highest electrical conductivity of all metals.\nSilver is classified as a transition metal. It is placed in period 5 and group 11 of the periodic table of elements.

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