Question

The normal gestation period in humans is
(a) 270 days
(b) 290 days
(c) 280 days
(d) 295 days

Answer 1

Hint: The duration of time required for development of foetus from day of conception till birth is called gestation period. During this period, growth of various organs of the foetus occurs at various time points. The gestational period is different in different species of animals.

Complete answer: In humans, gestation period consists of a day of fertilization plus 14 days i.e. two more weeks. It is considered as an approximate duration from when a woman’s last period began. Development of a human baby inside the mother’s womb requires an approximate duration of 40 weeks i.e. 280 .
Development of embryo till birth is also called prenatal development. In humans, the period of gestation i.e. 280 days are divided into three trimesters. First trimester is from week 1 to week 12. The fertilized egg in this stage is called zygote, it makes its way to the uterine wall and implants itself in the muscles of the wall in the initial days of the first trimester. Now the zygote will undergo multiple repeated divisions and first form morula, then blastula and then gastrula. By week 5, development of organs like heart and brain begins. Second trimester is from week 13 to week 27. In this period, the Musculo-skeletal system of the baby begins to develop and skin is forming but is translucent. Third trimester lasts from week 28 till birth. By this time, the baby has fully developed and is about 15 to 17 inches long.
So, the correct answer is '280 days.'

Note: Gestational period varies in animals. In cattle it is 270 to 290 days. In elephants it is 645 days or more. On horseback it is around 330 days. Least time is required for development in the mouse, their gestational period is 19 to 21 days only.