Capacitance of sperms takes place in:

Ans is 'd' i.e. Uterus Also see Q no. 157 of Nov 2007; Q no. 1 of May 2004Capacitation is the process of sperm maturation (or activation) that occurs post-ejaculation in the female genital tract\ particularly in the uterine tubes. Without capacitation sperm have a reduced capacity to fertilize the egg.After ejaculation spermatozoa do not have the capacity to fertilize the oocyte. They must undergo 2 processes to acquire this capability:Capacitation and b) Acrosome reactionCapacitation:Capacitation is a period of conditioning of the sperms in the female reproductive tract. It lasts for approx. 7 hours (l to 10 hrs). Some of the changes during capacitation are:The uterine and fallopian tube fluids wash away the various inhibitory factors that suppress sperm activity in the male genital ductsWhen spermatozoa are in male genital ducts, they are continually exposed to vesicles from seminiferous tubules containing large amounts of cholesterol. This cholesterol is continually added to the cellular membrane covering the sperm acrosome, toughening this membrane and preventing release of its enzymes. During capacitation the sperms lose this excess cholesterol making the membrane weaker and thus preparing the sperm for 'acrosome reaction'The motile properties of the spermatozoon also change. Whipping movements of the tail together with larger sideways swinging movements of the head take place. This type of motility is designated as hyperactivity.* Acrosome reaction:The acrosome reaction occurs after binding to the zona pellucida, and is induced by zona proteins. This reaction culminates in the release of enzymes from the acrosome, needed for spams to penetrate the zona pellucida into the ovum.