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What is the difference between sister chromatids and homologous pairs?

Homologous pairs are chromosome pairs, where one chromosome comes from the mother and the other comes from the father. They are present in diploid cells and are not identical, only similar. Sister chromatids are identical and are formed from the homologous pairs in meiosis I and separate in the meiosis II stage.

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How many grams are in a liter?

For example, a block of stone typically has more mass than a block of wood that is the same size, so the stone can be said to have greater density. Water is a convenient standard in the metric system, because it has a density that is very close to 1 gram per milliliter. If the substance in question is cold water, there are approximately 1,000 grams in a liter.

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What are some facts about adaptive evolution?

Reed canary grass is another species that has benefited from adaptive evolution. As many different invasive plants have entered its habitat, the reed canary grass has responded by producing a greater amount of biomass and boosting its rate of clonal reproduction in order to continue thriving.\nThe purple loosestrife and white campion have shown adaptive evolution in their shifting of internal resources away from mechanisms for defense and toward growth and reproduction, as selection pressures in their habitats have increased significantly. The hybrid cattail has developed a wider spectrum of t..

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What is the shaft of a long bone called?

The shaft is made up of compact bone that is covered with a strong membrane called the periosteum. Down the center of the shaft is a hollow that contains bone marrow.\nLong bones facilitate skeletal mobility and include the femur, fibula, tibia, ulna, radius and humerus. The phalanges and clavicles are also classified as long bones, even though they are smaller in comparison to the limbs.

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What are the types of hypotheses?

A simple hypothesis involves only two variables: one independent and one dependent. A complex hypothesis, meanwhile, involves multiple variables, such as two or more dependent and independent variables. A directional hypothesis is based on an established theory, while a non-directional hypothesis is used when there is insufficient scientific basis for the prediction. This type of hypothesis may be biased, as it does not necessarily state the nature of the relationship between the variables.Researchers use a null hypothesis when they predict that the variables are not correlated. An associative..

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What is the chemical formula for ethanoic acid?

The chemical formula indicates that the acid is composed of two atoms of carbon, four atoms of hydrogen and two atoms of oxygen. It is a weak acid that is part of a group of acids known as carboxylic acid. Ethanoic acid is a common component of vinegar. It is most often used in the production of various chemical compounds. Ethanoic acid has a molar mass of 60.05 grams per mole and a density of 1.04 grams per cubic centimeter.

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What is the job of the mitochondria?

Mitochondria are comprised of two major membranes. The outer membrane controls which molecules are allowed to enter and exit the mitochondrion. The inner membrane contains specialized enzymes that work together the convert glucose to ATP, and it is the primary site of cellular respiration.\nMitochondria are found within all plant and animal cells. Cells that use more energy tend to have more mitochondria. If the energy needs of a cell increase, the mitochondria replicate to increase in number. For example, as an athlete begins to work his or her muscles harder, these muscle cells develop more ..

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How was Oparin's hypothesis tested experimentally?

The experiment simulates early conditions on Earth by sealing water, ammonia, methane and hydrogen gas in a 500 milliliter flask. A continuous discharge of electricity runs through the gases as a substitute for lightening and solar radiation. The product is allowed to cool, condense and collect in a lower flask that is half-filled with liquid water. The liquid water in the second flask is heated so that the water can evaporate and recycle through the whole system.\nAfter just one day, matter begins to collect in the lower flask. In the original experiment, tests revealed 11 amino acids formed ..

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What is topsoil made of?

The composition of topsoil varies according to where it is collected. Each type of topsoil has a unique mixture of earth, organic materials and soil nutrients. The texture of quality topsoil tends to be fine compared to general dirt, which can be lumpy. Topsoil consisting of mostly clay retains a high level of moisture, which is suitable for plants in dry heat areas where water is scarce. Clay soil has a low acidity level, but requires heavy watering for saturation.\nSandy topsoil contains a lot of sand, which is more common in coastal areas. The downside of sandy topsoil is that it doesn&apos..

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How much does a $20 bill weigh?

The front of the $20 bill has featured Andrew Jackson, the seventh President of the United States, since 1928. The White House is on the back of the bill. Grover Cleveland was featured on the $20 bill prior to Jackson. The Treasury Department has never indicated why the initially featured president was changed. Andrew Jackson was not a proponent of paper currency during his presidency. The $20 bill with Grover Cleveland debuted in 1914, and the note featured a steam locomotive on the reverse side.

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