Question

3. A phenotypically abnormal individual has a phenotypically normal father with an inversion on one copy of chromosome 7 and a normal mother without any changes in chromosome structure. The order of genes along chromosome 7 in the father is as follows: normal chromosome 7) RTDM centromere P UXZC RTDUP centromere MXZC (inverted chromosome 7) The phenotypically abnormal offspring has a chromosome 7 with the following order of genes R TDM centromere P U D TR With a sketch (complete), explain how the abnormal chromosome was formed. In your answer, explain where the crossover occurred (i.e., between which two genes). Also, give any other products that might have been formed as a result of the crossover you described. Assume that crossing over does not occur at the centromere or across the centromere.

Answer 1

Solution:

8ased on he Siven data, ttere are to Mojo1 of invexsions, tteq are Paracentric invexsion Pericentic invexsion Examples o nesion5 are Ca) Normal chror o some AEDC8 FGH inverted renverted Teaion Cb) Pevicentic enesion → Henae chromosome 구〉, tken RTbvp centro mete MxZc cinverted chromesome ), hence it is a Pancenkic Hexe a sinjle crosoe occured betoeen in and P genes and te Products tormed are p and 1xz c. d are RTbU

→rle Phenotypvcatty abnormal epfspring has chromo sone t Litt oxdev 9f genes fTD 1 cetronte PuDTR. Hence, it (s Paracent' invers on, HHere a stngl CYossoer occured betcseen RTD and xy genes and tte Ptolu cts fovmed are RTDtn and a Stng