QUESTION 1: calculate a X2 value for the class data. The accepted distance for t

ID: 101090 • Letter: Q

Question

QUESTION 1:

calculate a X2 value for the class data. The accepted distance for these genes is 26 m.u. You will have to use this 26 m.u. to work back and figure out how many FDS and SDS should be present.

Table 1. Group data of the entire class.

Group name glasses Alyssa Franky and Isabel SJ Myliese and Ana Mohammad and Hamza Cameo and Juliana Ashour and Jack MK TOTALS SDS-second division segregation 47 20 25 25 23 27 29 23 22 241 #FDS FDS-first division segregation 53 30 25 25 27 23 21 27 28 259 # SDS TOTAL 100 50 50 50 50 50 50 50 50 500 TOTAL Asci # GENE CONVERSIONS 14 0 2 0 0 0 0 ? 16 total # of gene conversions

Explanation / Answer

To calculate X2 value we use following formula-

(Observed- Expected)2 / Expected items=

For the given table

Segregations

Observed (O)

Expected (E)

(O-E)2

(O-E)2 / E

SDS

259

250

(9)2 = 81

81/250 =0.324

FDS

241

250

(-9)2 = 81

0.324

Total

500

0.648

The expected FDS and SDS should share 50 -50 % of total segregations. Therefore, the expected FDS and SDS are 250 for each, for 500 total loci.

For 26 mu distance means there is 26% recombination occurs only 24% linkage is present. For 500 total loci we consider 52 % will be SDS (through recombination) and 48% will be FDS (through no crossover).

Therefore, the net number segregations would be-

For SDS = 500 x 52%

= 500 x 52/100 = 260

And for FDS = 500 x 48%

=or 500-260

= 240