physical characteristics of a human is your phenotype
something that describes someone
Well, a typical "he" will be male. In human, this means that "he" will produce hormone testosterone and not estrogen which is what "she" will produce. Also, "he" will not have a mammary glands...
Curtail is a verb meaning to limit, shorten or reduce i.e. In order to lose weight, one must curtail their food intake.
it could just mean someone else in the family has that characteristic.