Question

In humans normally what is the period of pregnancy?
A.$266$ days
B.$280$ days
C.$270$ days
D.$275$ days

Answer 1

The gestation period is the amount of time it takes for a foetus to develop from conception to birth. Various organs of the foetus grow at different times throughout this phase. Varied types of animals have different gestation periods.
Gestation is a pregnancy in which a woman bears one or more foetuses in her womb, sometimes more than one foetus at a time, such as twins, and it is mostly caused by sexual activity or assisted reproductive technologies.

Complete answer:
Option A: Prenatal development refers to the development of an embryo from conception until birth. The $280$-day gestation period in humans is divided into three trimesters. The second trimester lasts from week $13$ to week $27$ of pregnancy. The third trimester runs from week $28$ through the due date. The baby has reached full maturity at this point.
So option A is incorrect.
Option B: The gestation period in humans is made up of the day of fertilisation $+ 14$ days, or two weeks. It's a rough estimate of how long it's been since a woman's last period started. The development of a human infant inside the mother's womb takes around $40$ weeks, or $280$ days.
So option B is correct.
Option C: Animals have different gestation periods. It takes $270 - 290$ days for cattle.
So option C is not correct.
Option D: Pregnancy or gestation usually lasts $9$ months, but if we add in $31$ days for a month, it comes to roughly $38$ weeks. It's known as gestation age, and it lasts roughly $280$ days.
So option D is not correct.

So option B is the correct answer.

Note:
Trimesters are the three main stages of pregnancy.
During the first trimester, The female body undergoes significant changes as it prepares to accommodate a developing baby. The uterus begins to support the growth of the placenta and child. It is the most vulnerable time as all of his or her major organs and systems are developing.
Second trimester: For the majority of pregnant women, this is the most comfortable time (weeks $13 - 27$), since the uterus expands fast.
The third trimester begins in the $28$th week and ends at the birth of your baby. The first trimester of pregnancy is the most crucial.