|Age Range||5-8 (grades 1-2), 8-11 (grades 3-5), 11-14 (grades 6-8), 14-18 (grades 9-12)|
|Group Size||medium (6-20)|
|Setup Time||medium (6-30 min)|
|Duration||medium (11-30 min)|
|Subjects||polar animals, mammals, adaptation|
|Key terms||insulate, polar, habitat, adaptation, buoyant|
|Materials||thermometer, crisco (aka lard or fat), spoon, 2 plastic ziplock bags, duct tape, large bowl or pot, ice water|
|Presentation Style||interactive, model|
Students will put their hands into a plastic bag filled with lard. They will emerse their lard hand into ice water. The goal is to simulate what it is like to be a polar animal with a lot of blubber. The lard hand will not get as cold as a bare hand.
- Students will summarize evidence about polar animals.
- Students will identify how benefits of blubber.
Blubber is a type of fat that acts as an "insulator" (reduces the flow of heat) for animals like whales, walruses, seals and polar bears. Each of these animals is a mammal. As a warm blooded animal each must keep his body temperature constant no matter the environmental temperature. On average, a whale's body temperature is a couple degrees more then humans (98.6° F) but varies with each whale species. Because heat loss is much greater in water than in air, these marine mammals have blubber to help keep them warm.
Blubber thickness can vary from a few inches in smaller whales and dolphins, to over a foot thick in the right and bowhead whales. Penguins, along with all birds, are also warm blooded. Their chilly environment calls for them to have a thick layer of blubber as well in order to stay warm.
The major purpose of this activity is to give students experience in actively experimenting with how blubber acts as an insulator.
This Is How You Play
Before the Activity
- Put together ice water in a large bowl or pot.
- Show students pictures of polar animals (polar bear, penguin, whale, walrus, etc)
- Lead a discussion where students make observations about the polar animals. Guide them to observe that all of there animals appear “fat”. Discuss why.
- Ask the students to guess the temperature of the ice water.
- Use a thermometer to take the temperature of the water.
- Have the students take turns scooping Crisco into a Ziploc plastic bag.
- Turn the second bag inside out and insert it into the first bag.
- "Zip" the two bags together, trapping the fat in between. This Crisco Layer is the layer of blubber that will insulate a hand from the cold water.
- Place a hand inside the mitt and spread the "blubber" around between the two bags to create an even layer of blubber.
- Have each student place his hand into the blubber mitt and then into the bowl of ice water without letting the uncovered part of his arm touch the water.
- Count to 60. Ask the students if they can feel the cold. Why not?
- Next, have the students try placing their hands in the ice water without the blubber mitt. How long can they keep their hand in the ice water without it getting uncomfortably cold?
- Discuss the differences between humans and polar animals. Lead the students to make observations of the fat on a human body. Where is it? What is it protecting? The fat layers on humans are not as thick as the fat layers on polar. What ways do humans keep warm instead? (shiver, blow in our hands, turn up the heat, put our hands in warm spots like under our arms or between our legs, cover up with layers)
- When humans stay in the water for long periods of time what do we need? (wet suits, dry suits, a submarine with a controlled temperature). A human being without any protection in water at 32°F or 0°C can loose consciousness in ten minutes.
- What other purpose does blubber serve for these marine animals? (buoyancy) Place the blubber mitt in the water. Does the mitt float? (Yes, so blubber helps the animals float in the water.)
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