The answer is negative controls. These are groups where no phenomenon is probable. They ensure that there is no effect when there should be no effect. Where there are only two possible outcomes, e.g. positive or negative, if the treatment group and the negative control both produce a negative result, it can be concluded that the treatment had no effect. If the negative control group and the treatment group both yield a positive result, it can be inferred that a puzzling variable is involved in the occurrence under study, and the positive results are not only due to the treatment. In other examples, outcomes might be measured as lengths, times, percentages, and so forth.
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breed the red hamsters with blue eyes in hopes of getting their babies and sell them.... I have no idea what else you could do lol.
Darwin concluded that the sea level was high were it reached the mountain and as times passed sea level lowers down and clams were still on the mountain so when they died they were fossilized in the mountains. Hope this helps
<span>previous changes in climate were dramatic but very short-lived.
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<span>The issue of whether human activities cause global climate change is indeed a controversial topic. The limitation to climate research that could be overcome through scientific design is "Data from a wide range of time periods must be analyzed." Very powerful, or Super Computers, are required to analyze large amounts of data. The sooner more powerful computers are developed, the sooner data from the wide range of time periods can be analyzed. This will give scientists a better idea of the extent of global warming, if any, and how to prevent it.
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The simplest mechanism by which molecules can cross the plasma membrane is passive diffusion. Passive diffusion is thus a nonselective process by which any molecule able to dissolve in the phospholipid bilayer is able to cross the plasma membrane and equilibrate between the inside and outside of the cell.