Mouse pregnancy experiment
The weight increase of the female mouse and fetus during pregnancy.
At what rate does a female mouse gain weight during pregnancy?
• Unlike humans, mice bear multiple young.
• The fetus grows by cells dividing at approximately an exponential rate.
• The fetus develops the most during the first trimester.
If a healthy female mouse gets pregnant, then excluding the weight she gains from simply growing, she will gain weight at a bit less than an exponential rate.
o The state in which an animal has developing young growing in the uterus.
• Exponential rate
o The rate at which a number increases if exponents are applied. Increases rapidly.
• The weight gained from growing
o The weight a being gains with no outside cause.
o Baby mice
• One female mouse that is fertile
• One male mouse that is fertile
• A 100 gram scale
• Pencil and paper to record data
• Mouse care materials
o Three mouse cages
o Mouse bedding
o Water bottle made for small animals
o Exercise wheel
o Any toys / accessories
Lab safety and protocol:
• MAKE SURE TO FIND LOVING HOMES FOR ALL THE BABIE MICE!
• BE HUMANE TO MICE!
• Do not pick up pregnant mouse by belly or the tail, the tail can come off
• Sex the baby mice as soon as they are weaned. Separate the males into another cage (not the one with the father).
• Handle mice with care, they may bite
o Do not squeeze
o Do not grab
o Do not dangle by tail unless necessary
• Do not allow pregnant mouse to smell any male mouse other than her mate or she will abort her litter
Variables and constants:
Constants: Independent variables: Dependent variables:
• The individual parent mice
• Amount of food available • Time of year
• How many litters she had before the experiment • Gestation period
• Size of pups
• Number of pups
1. Purchase all necessary items
2. Weigh and observe the female mouse twice a day every day from this point foreword
3. Put the male and female mouse in the same cage away from other animals
4. Wait at least one week (or until the female mouse is obviously pregnant)
5. Remove the male mouse into a different cage BEFORE the female gives birth
6. Weigh the female mouse as soon as possible after the pups are born
7. As soon as possible after the pups are weaned, sex them and separate the males into the third cage, the females can stay with the mother
Data and observations:
(The 3 weightings that are missing are because I did not receive data sheets from Alie, despite asking repeatedly. The text size was made smaller so that it would take less room.)
20-Mar 7:00:00 A.M. 22.4 Storing food. Starting to sleep more. Peaches and cheese seem to like each other.
7:00:00 P.M. 22.1 -0.3
21-Mar 7:00:00 A.M. 22.3 0.2 Vaginal plug discovered in Peaches. Pregnant?...