## How do you calculate chi-squared in biology?

In the Chi-Square test, these are your OBSERVED values. Now that you have OBSERVED and EXPECTED values, apply the Chi-Square formula in each part of the contingency table by determining (O-E)2 / E for each box. The final calculated chi-square value is determined by summing the values: X2 = 0.0 + 0.1 = 0.1 + 0.2 = 0.4.

## How do you work out the Hardy Weinberg principle?

The Hardy-Weinberg equation used to determine genotype frequencies is: p2 + 2pq + q2 = 1. Where ‘p2’ represents the frequency of the homozygous dominant genotype (AA), ‘2pq’ the frequency of the heterozygous genotype (Aa) and ‘q2’ the frequency of the homozygous recessive genotype (aa).

## What is P in AP Bio?

p. Mode = value that occurs most frequently in a data set. Median = middle value that separates the greater and lesser halves of a data set. Mean = sum of all data points divided by number of data points. Range= value obtained by subtracting the smallest observation (sample minimum) from the greatest (sample maximum)

## What is a chi-square test used for in biology?

Chi squared is a statistical test that is used either to test whether there is a significant difference, goodness of fit or an association between observed and expected values.

## When to use chi-squared to test for Hardy Weinberg equilibrium?

Chi-squared is a statistical test used to determine if observed data (o) is equivalent to expected data (e). A population is at Hardy-Weinberg equilibrium for a gene if five conditions are met; random mating, no mutation, no gene flow, no natural selection, and large population size.

## When is a population at Hardy Weinberg equilibrium?

A population is at Hardy-Weinberg equilibrium for a gene if five conditions are met; random mating, no mutation, no gene flow, no natural selection, and large population size. Under these circumstances, the allele frequencies for a population are expected to remain consistent (equilibrium) over time.

## What is the frequency of the recessive allele in Hardy Weinberg equilibrium?

In a population that is in Hardy-Weinberg equilibrium, the frequency of the recessive homozygote genotype of a certain trait is 0.09. Calculate the percentage of individuals homozygous for the dominant allele. We know that the frequency of the recessive homozygote genotype is q2 and equal to 0.09.

## What is the critical value of chi squared?

The resulting chi-squared value is 13.71. For a p-value of.05 and 1 degree of freedom (df = 1 is generally used for HW even when there are three phenotypes because the expected can be calculated starting with one of the two alleles*), the critical value is 3.84.