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Gestation Periods

GESTATION - Key information


What is gestation?


Nearly all mammals are viviparous. This means that they give birth to live young, rather than laying eggs. The time between the fertilisation of the egg cell and the birth of the offspring is called the gestation period.


During the gestation period, the offspring develops inside the mother's womb. It starts off as a single cell called a zygote and then develops into an embryo composed of many cells. As time goes on, the embryo becomes a foetus, with more recognisable features such as skin, bones, blood and organs.

The fully-developed baby (animal, including humans) exits the mother's body at the end of the gestation period. Gestation periods are different for different mammals.

Video 1: How long is pregnancy for animals | Gestation Period

How long is pregnancy for animals | Gestation Period We owe a lot to our mothers. They carried us for about nine months before giving birth. Human mothers ha...

BRITANNICA FILE: The shortest and longest mammal pregnancies

Almost all mammals give birth to live young, but the length of their pregnancy, or gestation period, can vary a lot. Which mammals have the longest, and shor...

Cut and paste the printed images of the  animals into the gestation table. Then use the internet or reference books if you have them to find out the average number of babies each animal has per pregnancy and its average life span.  Record your findings in the gestation table.


Once you have completed all the facts in the gestation table, answer question 4 - 10. 


You may need an adult to help you with this.  Look at the information you  found out about gestation periods, analyse it and try to spot whether or not there are any patterns.  What do you notice?  There aren't any answers to this activity. It's up to you (the scientist) to hypothesise and make links, if there are any.