In: Biology
Determine the Chi Suquare for this table, remember thet yellow mutant is a sex-lincked gene. Show all the work.
Cross 1: Dumpy Males x Yellow Females |
|||
Males |
Females |
Total |
|
Wild Type |
23 |
27 |
50 |
Mutant A (Yellow ) |
14 |
5 |
19 |
Mutant B (Dumpy) |
6 |
7 |
13 |
Double Mutant AB |
4 |
2 |
6 |
Total |
47 |
41 |
Cross 1: Dumpy Males x Yellow Females | |||
---|---|---|---|
Males | Females | Total | |
Wild Type | 23 | 27 | 50 |
Mutant A (Yellow ) | 14 | 5 | 19 |
Mutant B (Dumpy) | 6 | 7 | 13 |
Double Mutant AB | 4 | 2 | 6 |
Total | 47 | 41 | 88 (Grand Total) |
Null hypothesis = The genes for color & height are assorted independently.
Phenotype | Number Observed |
Number Expected |
---|---|---|
Wild type male | 23 | (50 x 47)/88 = 26.70 |
Wild type female | 27 | (50 x 41)/88 = 23.30 |
Mutant A (Yellow) male | 14 | (19 x 47)/88 = 10.15 |
Mutant A (Yellow) female | 5 | (19 x 41)/88 = 8.85 |
Mutant B (Dumpy) male | 6 | (13 x 47)/88 = 6.94 |
Mutant B (Dumpy) female | 7 | (13 x 41)/88 = 6.06 |
Double mutant AB male | 4 | (6 x 47)/88 = 3.20 |
Double mutant AB female | 2 | (6 x 41)/88 = 2.80 |
2 = (Observed - Expected)2/Expected
= (23-26.70)2/26.70 + (27-23.30)2/23.30 + (14-10.15)2/10.15 + (5-8.85)2/8.85 + (6-6.94)2/6.94 + (7-6.06)2/6.06 + (4-3.20)2/3.20 + (2-2.80)2/2.80
= 0.51 + 0.59 + 1.46 + 1.67 + 0.13 + 0.15 + 0.2 + 0.23
= 4.94
Degree of freedom (df) = (number of rows – 1) x (number of columns – 1) = (4-1) x (2-1) = 3 x 1 = 3
We find that probability from 2 distribution table is 0.1 < P < 0.5.
The probability associated with the calculated chi-square value is between 0.10 and 0.50, indicating a high probability that the difference between observed and expected values is due to chance.