Submitted by Anonymous on Thu, 10/22/2009 - 08:57
Forums
Polar Bear Response to Sea Ice Loss

Hello Christina, My name is Beto from New Start Middle School in Flagstaff,Airzona. I have two question about the polar bears. How will the polar bears effect us if they all go extinct? Why do you guys take fat from the polar bears? I live in Airzona there are no ploar bears here.

                                     Thank you for your time,



                                                              Beto
Thu, 10/22/2009 - 10:45

Cristina Galvan

Hi Beto!The team takes a fat sample from the polar bears in order to estimate
how much fat the bears have in the rest of the body. They can do that
in a couple of ways. The first is they look at the The first is they
can look at the depth of the fat of the bear - the deeper the fat layer
is, the more fat the bear has.
The second is that they look at the fat content of the fat cells. As the
bear gets fatter, they don't gain more fat cells, the fat cells simply
get bigger. The team looks at the cells under a microscope and looks at
the cells. Inside a fat cell is a vacuole that holds fat - more fat in
a cell means they can assume there is more fat overall in the bear.
Imagine the cells as a plastic bag, inside that plastic bag is lots of
different organelles that do different jobs. Inside the bag, is another
bag (vacuole) - it's job is to store fat for use later when food supply
is low. The team wants to know how much fat is inside those vacuoles.
Another reason they take a fat sample is to complete chemical analysis
to determine what exactly they are have been eating. I'm not sure if
you have learned about isotopes yet, but scientist can use them to
determine what the bears have been eating.
Your first question about polar bear extinction and the affects on you
in Arizona is a good one, but complicated question. I wrote up an
explanation for your classmate Parker - check out the explanation in his
post titled "Polar Ice."
Please let me know if you have more questions I can help with.
Thanks,
Ms Galvan