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You are working with tomatoes and you do a dihybrid cross. You get 250 individuals and the ratio is 135:47:53:15. You do a Chi Square to determine if the ratio follows Mendel’s prediction and get this value: X2 = 1.04. TRUE or FALSE: This cross showing simple dominance (see table below for Chi Square value at 95% confidence). df X2 crit 1 3.84 2 5.99 3 7.81 4 9.49 5 11.07 6 12.59

User JSK
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Final answer:

The Chi Square value of 1.04 is less than the critical value of 7.81 for 3 degrees of freedom at the 95% confidence level. Thus, the observed dihybrid cross of tomatoes appears to correctly follow Mendel's expected 9:3:3:1 ratio, indicative of simple dominance and independent assortment. Hence it is true.

Step-by-step explanation:

The question deals with a dihybrid cross of tomatoes and determining whether the observed phenotypic ratio follows Mendel's prediction of a 9:3:3:1 dihybrid ratio, indicative of independent assortment and simple dominance. The Chi Square value obtained from the cross is 1.04.

When conducting a dihybrid cross in Mendelian genetics, we expect a 9:3:3:1 ratio if the genes assort independently. Using the product rule, we can calculate the expected proportions for each phenotype. In the cross given, to determine if the observed ratio fits Mendel's expected ratio, we use the Chi Square test.

The critical value from the Chi Square table for 3 degrees of freedom at the 95% confidence level is 7.81. Since the calculated Chi Square value of 1.04 is less than the critical value, we do not reject the null hypothesis. Therefore, the result is consistent with the expected Mendelian ratio which shows simple dominance for two traits.

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User Itstoocold
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