The Chi-Squared Test
The statistics section of the AP Biology exam is without a doubt one of the most notoriously difficult sections. Biology students are comfortable with memorizing and understanding content, which is why this topic seems like the most difficult to master. In this article, The Chi Square Test: AP Biology Crash Course, we will teach you a system for how to perform the Chi Square test every time. We will begin by reviewing some topics that you must know about statistics before you can complete the Chi Square test. Next, we will simplify the equation by defining each of the Chi Square variables. We will then use a simple example as practice to make sure that we have learned every part of the equation. Finally, we will finish with reviewing a more difficult question that you could see on your AP Biology exam.
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Hardy-Weinberg Equilibrium
On the AP Biology exam, you may be asked to predict the frequency of specific genetic traits in a given population. To determine this frequency, we use what is known as the Hardy-Weinberg equation. This equation is a mathematical expression that illustrates the relationship between the frequencies of all genotypes present in the population in question.
Water Potential
Water potential is the potential energy of water per unit volume relative to pure water in reference conditions. Water potential quantifies the tendency of water to move from one area to another due to osmosis, gravity, mechanical pressure, or matrix effects such as capillary action which is caused by surface tension. The concept of water potential has proved useful in understanding and computing water movement in plants, animals, and soil. Water potential is typically expressed in potential energy per unit volume and very often is represented by the Greek letter ψ.