Question

Assume that a cross is made between a heterozygous tall pea plant and a homozygous short pea plant. Fifty offspring are produced in the following frequency:30 = tall20 = shortNull hypothesis: The deviations from a 1:1 ratio (25 tall and 25 short) are due to chance.What is the Chi-square value associated with the appropriate test of significance?

Answer 1

Chi-square value = 2

Explanation:

Given data:

Frequency: Tall Short

30 20

Null hypothesis ( as it is already given so there is no difference between observed and expected values)

Ratio: 1:1 (50% expected frequency of each tall and short pea-plant)

Solution:

Phenotype Observed Expected O-E (O-E)² (O-E)
`^(2/E)`

O E

Short 20 25 -5 25 1

TALL 30 25 5 25 1

TOTAL 2

So, from all these calculations using expected and observed values we get chi-square value equal to 2.