Chi Square Bio340
ASU Exam
Questions and
Complete Solutions
Graded A+
Denning [Date] [Course title]
,Null hypothesis: H0 - Correct Ans: • there is no association between two phenomena
• there is no effect by a drug on a disease
• there is no linkage between two genes
• there is no evolution occurring in the gene pool
Alternative hypothesis: H1 - Correct Ans: An alternative hypothesis (H1) is the rival to the
null and defines the rejection region
• One-tailed: the region of rejection is in one tail of
the sample
• Our company's new drug works better than the
competitor's
• Two-tailed: the region of reject is in both tails of
the sample
• Our company's new drug works differently than
the competitor's
If we can reject the null hypothesis, we say
there is evidence for the alternative hypothesis
Histogram of results - Correct Ans: With a significance level of
0.05, you have a 5%
chance of rejecting the null
hypothesis, even if it is
true. 5% of your
experiments will give you
data that are significantly
different, just by chanc
Dihybrid test cross
, What is our null hypothesis H0 for genotype ratios?
GgWw x ggww - Correct Ans: phenotype Genotype Probability
Dominant for both traits Gg Ww
Dominant for the first and
recessive for the second Gg ww
Recessive for the first and
dominant for the second gg Ww
Recessive for both gg ww
GgWw Ggww gg Ww gg ww
Observed 5 45 45 5
Obs. Ratio 1 9 9 1
Expected 25 25 25 25
Exp. Ratio 1 1 1 1
How are we going to test the null hypothesis
with four categories? - Correct Ans: Pearson's chi-squared test (test
statistic)
Pearson's chi-squared test (test
statistic) - Correct Ans: Pearson's X2 allows you to summarize your
observed data into a single value
• Pearson's X2 statistic allows us to summarize how
well our observed offspring numbers fit the
expected numbers
• Important: the sum uses counts not ratios
AND takes over all offspring types
chi-squared test (test
ASU Exam
Questions and
Complete Solutions
Graded A+
Denning [Date] [Course title]
,Null hypothesis: H0 - Correct Ans: • there is no association between two phenomena
• there is no effect by a drug on a disease
• there is no linkage between two genes
• there is no evolution occurring in the gene pool
Alternative hypothesis: H1 - Correct Ans: An alternative hypothesis (H1) is the rival to the
null and defines the rejection region
• One-tailed: the region of rejection is in one tail of
the sample
• Our company's new drug works better than the
competitor's
• Two-tailed: the region of reject is in both tails of
the sample
• Our company's new drug works differently than
the competitor's
If we can reject the null hypothesis, we say
there is evidence for the alternative hypothesis
Histogram of results - Correct Ans: With a significance level of
0.05, you have a 5%
chance of rejecting the null
hypothesis, even if it is
true. 5% of your
experiments will give you
data that are significantly
different, just by chanc
Dihybrid test cross
, What is our null hypothesis H0 for genotype ratios?
GgWw x ggww - Correct Ans: phenotype Genotype Probability
Dominant for both traits Gg Ww
Dominant for the first and
recessive for the second Gg ww
Recessive for the first and
dominant for the second gg Ww
Recessive for both gg ww
GgWw Ggww gg Ww gg ww
Observed 5 45 45 5
Obs. Ratio 1 9 9 1
Expected 25 25 25 25
Exp. Ratio 1 1 1 1
How are we going to test the null hypothesis
with four categories? - Correct Ans: Pearson's chi-squared test (test
statistic)
Pearson's chi-squared test (test
statistic) - Correct Ans: Pearson's X2 allows you to summarize your
observed data into a single value
• Pearson's X2 statistic allows us to summarize how
well our observed offspring numbers fit the
expected numbers
• Important: the sum uses counts not ratios
AND takes over all offspring types
chi-squared test (test
