were more boys
Were more boys or girls born to atomic-bomb survivors?
Normally, somewhat more pregnancies terminate in boys than girls in all populations, and this normal preponderance of male births has not been demonstrated to be significantly altered when the parents (one or both) were exposed to atomic radiation. However, when the genetic studies began, it was believed that a person's gender was simply determined. Individuals inheriting an X chromosome from their father and one from their mother were destined to be females; whereas those individuals who inherited a Y chromosome from their father and an X from their mother would be males. Thus, females would have two X chromosomes and males only one. These notions suggested, in turn, that when mutations induced in the X chromosome by ionizing radiation are incompatible with survival (are lethal), their expression would be manifested differently in the two genders and would depend, partly, upon whether the X chromos...