Ms. Shaeffer's Multimedia Blog: 8th Grade River Otters Science (View fusionpage home)
Cow gas is responsible for about 20 percent of U.S. emissions of methane release. Methane traps 20% more heat in the atmosphere than carbon dioxide, the gas which most frequently gets a bad rap in global warming arguments.
Grass-fed cattle produce beef with less saturated fat for the consumer, but cause more methane gas to be produced by the cattle. Why? Lignin, a hard-to-digest substance in the cell wall of the grass is resistant to ordinary digestion. As lignin goes through the digestion process, methane gas is produced.
Scientists have begun to help cows with their flatulence problems. An Australian company has developed genetically modified grass that contains less lignin and therefore decreases methane production from grass-fed cattle. It seems like a win-win...a healthier beef with less saturated fat AND less methane released into our atmosphere!
How has science changed the beef industry? How is science helping global warming? Do you think it is okay to feed a cow genetically modified grass?
SOURCE: Discover Magazine, August, 2008
|Posted by Ms. Shaeffer at 2:52 PM | 18 comments|
a Jaguar with a wooly mammoth?
A fancy car with shaggy upholstery and a big trunk.
Wooly mammoths are extinct, disappearing between 8,000 and 10,000 B.C. They were adapted to living in extreme cold, especially in Siberian regions. Using climate models and fossil remains, scientists have determined that the mammoth died out due to warming temperatures and the introduction of humans to the area.
Mammoths were covered in thick, shaggy hair, enabling them to survive in the frigid temperatures of the ice age. There is no environment suitable for them now. These animals were also extremely large, with their tusks alone reaching lengths of up to 16 feet!
Scientists are hoping to clone a year old baby wooly mammoth found in May of 2007. It was found in Russia after being buried for 37,000 years. To date 39 bodies have been found, but only four are complete. Attempts were made to clone another mammoth in 1997 but no DNA samples were found.
Do you feel it is OK to attempt to clone a wooly mammoth or other extinct animal? What benefits could there be if the attempt is successful? What challenges may arise?
|Posted by Ms. Shaeffer at 1:05 PM | 20 comments|
“You look just like your Aunt Sarah.”
“You’re the spitting image of Grandpa Fred.”
“You inherited the Smith nose.”
If you’ve ever heard comments like these, you know that the way you look has something to do with the way your relatives look. Through the generations, traits have been continuously passed down through the combination of an egg cell and sperm cell. All of your physical traits are coded in your genes which are located on the chromosomes in the nucleus of each of your approximately 60 trillion cells.
Studies indicate that each human being has approximately 25,000 genes. The Human Genome Project completed its mapping of the human genome in 2003. The goals of the project were to:
- Identify all the genes in human DNA
- Determine the sequence of the chemical pairs of DNA
- Store the information in databases
- Improve tools for data analysis
- Transfer technologies to the private sector
- Address ethical, legal and social issues that may arise from the project
Scientists hope that this mapping of the human genome will allow for breakthroughs in medical technology as specific genes are located for such diseases as cancer and Alzheimer’s disease.
What ethical issues do you think may arise from the Human Genome Project? Are the potential medical breakthroughs worth any challenges that may arise? Other than potential for curing disease, what else might this information be used for?