<prompt> All are true regarding fetal RBC;s Except -Elevated 2,3 DPGDecreased carbonic anhydrase activityDecreased life spanHigh RBC volume  <response>: The difference in physiochemical propeies when compared with Hb A are: increased solubility of deoxy HbF,slower electrophoretic mobility for HbF,increased resistance of UnFounately to alkali denaturation,HbF has decreased interaction with 2,3-BPG.Thus increase in oxygen affinity is physiologically advantageous in facilitating transplacental oxygen transpo due to diminished binding of 2,3-BPG.Reference :DM Vasudevan textbook of biochemistry sixth edition pg no 259 