Tuesday, September 10, 2013
about sharks teeth (facts from scientist website)
In fact, if it weren’t for shark’s teeth, we would know very little about prehistoric sharks at all! Since sharks are cartilaginous fish, their teeth are often the only part of their bodies that entered the fossil record. This is because shark teeth are modified placoid scales, which, like our own teeth, consist of a central pulp cavity surrounded by dentine and a hard enamel surface. Shark teeth are used almost exclusively to classify ancient species of sharks. Some prehistoric sharks are known to scientists only by the shape and size of their teeth.When you consider the number of teeth a shark uses during this lifetime, this information is hardly a surprise. A shark’s teeth are arranged in rows, the number of which varies from species to species. The row nearest the front of the mouth is the “working” row of teeth (though some sharks use up to the first 8 rows of teeth), and they are the largest teeth in a sharks’ mouth. The second row of teeth is smaller than the first row of teeth, the third row of teeth is smaller than the fourth row, and so on. Every time a shark loses a tooth, the tooth in the row behind it moves up to take the lost tooth’s place. This is possible because sharks’ teeth are not embedded in the jaw, but are attached to the skin covering the jaw.New teeth are continually grown in a groove in the shark’s mouth and the skin acts as a “conveyor belt” to move the teeth forward into new positions. Sharks’ specialized teeth have allowed sharks to develop a very strong jaw. Without the ability to quickly replace teeth, a shark’s jaw could not have developed as powerful of a bite. The number of teeth they routinely lose while catching prey would outweigh the quick-kill benefits of their crushing jaw strength.Sharks that typically eat fish have long, narrow, needle-like teeth ideal for gripping something as slippery and streamlined as a fish.Tiger sharks, great white sharks, and other sharks that primarily eat seals and other mammals have sharp, serrated cutting teeth for tearing off chunks of flesh.Finally, we have the gentle giants of the shark family, the basking sharks and whale sharks, that eat krill and other forms of plankton. While they have many teeth, they are tiny and useless, as these sharks feed by filtering water through their gills. https://www.sharksavers.org/en/education/biology/shark-teeth1/
Thursday, September 5, 2013
4E INQUIRY PROJECTS
Please enjoy our Inquiry Projects! Our class chose 5 questions and set out to discover some answers. We followed a process of inquiry that scientists use called the Scientific Method. Each post below takes us on a journey through these six steps:
4th Grade, you did a stupendous job! Thanks for all your hard work. A VERY special THANK YOU to Ms. Graham for all the help she was to us!!!!
Payton's Inquiry-Popcorn
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1. Why does popcorn pop?
http://www.popcorn.org/ForTeachers/TeachingGuide/WhatMakesPopcornPop/tabid/88/Default.aspx
- As the kernel heats up, the water begins to expand.
- Popcorn is a marvel.
- The pressure inside the grain will reach 135 pounds per square inch before finally bursting the hullopen.
3. Hypothesis: I think popcorn pops so you can eat the popcorn.
4.
4.
5. The popcorn was spinning and it took awhile to pop and it popped. I saw the steam and it started to go up.
6. Popcorn pops because there is water in the popcorn. Then the water heats up. Then the popcorn is heats up to 347 degrees. The water gets bigger and then the popcorn pops.
Grace's Inquiry-Marshmallows
1. Why do marshmallows expand in the microwave?
2. http://scienceline.ucsb.edu/getkey.php?key=783
http://www.newton.dep.anl.gov/askasci/chem03/chem03338.htm
- I learned marshmallows have tiny holes.
- I learned they’re made of sugar.
- I learned they expand in heat.
3. Hypothesis: The heat melts them to make them gooey.
http://www.newton.dep.anl.gov/askasci/chem03/chem03338.htm
4.
5. It deflated and it got crispy. I really like it crispy.
6. I guessed that because the heat would make marshmallows expand and make them gooey. They expand because it is full of air. The air then expands and gets all gooey. They’re made of gelatin that melts fast.
Eric's Inquiry-Yeast
1. Why does yeast make bread rise?
http://questionmaster.hubpages.com/hub/Why-does-bread-rise-dough
- I learned that the yeast goes up because of sugar.
- I learned that when the yeast goes up it pushes air.
- I learned that when the air pushes up it blows up the balloon.
3. Hypothesis: I think the reason bread rises is that as it is eating the sugar, it creates more bread and as it is creating more bread it is pushing air out to make the balloon blow up.
4.
4.
5. As yeast is eating the sugar, it is blowing up the balloon.
6. I learned that the yeast rises from sugar and pushes air in the balloon.
Kayley`s Inquiry-Popcorn
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1. Why does popcorn pop?
2. http://www.tellmewhyfacts./2006/11/why-does-popcorn-pop.html
- I learned that popcorn has water in it.
- I learned that popcorn pops because the heat makes it jump around and pop.
- Lastly, I learned that when popcorn gets so hot steam and water comes out.
3. My hypothesis: It pops because the heat pops it.
4.
5. I saw that the test tube burned and that steam and water came out. A cloud of steam traveled up the tube.
AJ's Inquiry-Salt
1. Why do we add salt to food?
- I learned that we can detect four tastes- sweet, sour, bitter, and salt.
- I learned that if you have a dish that tastes flat or bitter, a little salt might be the only fix you need.
- Too much salt, however, can cause high blood pressure and damage to blood vessels.
3. Hypothesis: maybe to make food taste really good.
4.
4.
5. It was bubbling a lot. It tasted gross. The water made me sick. This tonic water was really nasty. The tonic water was bubbling when I put some salt in it.
6. My hypothesis was correct. Salt is used to make food taste better. It cancels the bitter and makes it taste better.
Arayana's Inquiry- Popcorn
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1. Why does popcorn pop?
- I learned that during the Great Depression popcorn was 5 to 10 cents.
- Popcorn businesses thrived, and became a source to most farmers.
- Popcorn stores a little bit of water.
3. My hypothesis was popcorn pops because the heat gets to the seed and it makes it goes pop!
4.
4.
5. It was spinning around and as it got hotter it started to pop in the hot air popper. When we put it in a test tube I saw the steam going up the tube.
6. I learned that it has water stored in the kernels. The way popcorn pops lies in the fact that the kernels have water stored in them. The heat makes the water expand and makes it go POP!
Isabelle's Inquiry - Lifesavers
1. Why do wintergreen mints spark in the dark?
2. http://www.exploratorium.edu/cooking/candy/activity-lightning.html
http://kids.discovery.com/activities/science-experiments/light-up-lifesavers
http://kids.discovery.com/activities/science-experiments/light-up-lifesavers
- I learned that Wintergreen mints spark from electric fields.
- I learned you cause friction when you bite the mint.
- I learned that lighting makes electric fields like the wintergreen mints.
3. My hypothesis: The chemicals in the mint make it spark in the dark.
4.
4.
5. I didn’t see any sparks. I might have seen it, but my eyes weren’t adjusted completely.
6. My hypothesis was partly correct. When you crunch on wintergreen candies, you are making light with friction. The scientific name for this process is triboluminescence, from the Greek word tribein, which means “to rub,” and the Latin word lumin, which means “light.” The mints and lighting both make electric fields. You cause friction when you bite the mint. There’s a special oil in this type of mint that makes ultraviolet light into a visible blue light.
Myah's Inquiry-Marshmallow
1. Why do marshmallows expand in the microwave?
- I learned that a marshmallow expands when heat gets into the little holes of the marshmallow.
- I also learned that the reason why a marshmallow turns black is because when the suger gets warm it turns black and makes the marshmallow swell a little bit.
- Marshmallows melt and expand because they have holes in them that lets in heat and gets all gooey but candy does not have as many holes so it does not expand and melt as easily and get all mushy and gooey.
3. HYPOTHESIS Maybe marshmallows expand when heat gets into the marshmallow and pushes the marshmallow around.
4.
4.
5. It is all gooey and mushy. One is really sticky and hard. It is crunchy and good. They are also very puffy.
I see that the inside is like a tanish color. The face is all messed up. They are now flat and hard but it is still a little gooey. And the marshmallow is sticking to the paper towel.
6. My hypothesis was almost correct. I learned that it turns because the sugar gets warm and the marshmallow gets all black. When the marshmallow was in the microwave it got all puffy because the heat made it such a big blob but, when I took the marshmallow out it started to go down and get flat. The marshmallow expanded in the microwave because when the heat got into the little holes of the the marshmallows it pushed the marshmallow all around. But if you put a piece of candy in the microwave it won’t expand and get all mushy because it does not have holes like a marshmallow does.
Jacob's Inquiry-Lifesavers
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1. Why do Wintergreen LifeSavers spark in the dark?
2.http://thehappyscientist.com/science-experiment/light-lifesave
They spark in the dark.
- They contain sugar crystals.
- The crystals have a positive charge on one side and a negative charge on the other.
4.
5. Someone saw a spark. I didn’t see anything. We went into the utility closet. It was dark in there.
6. My hypothesis was right. They have a special ingredient. The wintergreen lifesavers have a chemical that makes it glow blue. There has to be no light or little light and you bite on it hard. This crushes the sugar crystals.
Mia's Inquiry - Salt
1. WHY DO WE ADD SALT TO FOOD?
lorecuriocity.org/Content.aspx?contentid=164#sthash.fXfCJbRW.dpuf
- IF YOU DON’T LIKE A FOOD AND IT TASTES BITTER, YOU CAN PUT SALT IN IT.
- TOO MUCH SALT IS BAD FOR YOU!
- I LEARNED IF YOU PUT ICE AND SALT IS YOUR HAND AND SQUEEZE IT, IT BURN YOUR HAND!
3. Hypothesis= IF YOU DON’T LIKE THE FOOD THAT MUCH YOU CAN ADD A LITTLE SALT TO MAKE IT TASTE A LITTLE BETTER!
4.
4.
5. The first time it tasted bad, the second time it tasted like 7up and it tasted good, the last two times it tasted SO SO TERRIBLY BAD!!!
6. I learned that we just like the taste of salt, and it helps make food taste better. Too much salt doesn’t taste good. I learned if you mix tonic water and two pinches of salt it taste like seven up. Two pinches of salt made it taste good because if you don’t go overboard with it, salt makes things taste less bitter.
Emily's Inquiry- Yeast
1. Why does yeast make bread rise?
- I learned that yeast is very common.
- I learned that bread keeps the bubbles in.
- I learned that many kids will know that yeast is used to make bread.
3. Hypothesis: The yeast goes into the bread and forms.
4.
4.
5. I see a balloon that is blown up. Before, it was on its side and now it can stand up by itself.
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