Stems Feb. 2, 2010
January 27, 2010
Vas (vessel) vasoconstrictor, cardiovascular, vase, vesicle, vascular, vasectomy
Cell Presentation 2010
January 27, 2010
Ethanol-Powered Vehicles Generate More Ozone Than Gas-Powered Ones
January 27, 2010
Ethanol — often promoted as a clean-burning, renewable fuel that could help wean the nation from oil — would likely worsen health problems caused by ozone, compared with gasoline, especially in winter, according to a new study led by Stanford researchers.
Ozone production from both gasoline and E85, a blend of gasoline and ethanol that is 85 percent ethanol, is greater in warm sunny weather than during the cold weather and short days of winter, because heat and sunlight contribute to ozone formation. But E85 produces different byproducts of combustion than gasoline and generates substantially more aldehydes, which are precursors to ozone.
“What we found is that at the warmer temperatures, with E85, there is a slight increase in ozone compared to what gasoline would produce,” said Diana Ginnebaugh, a doctoral candidate in civil and environmental engineering, who worked on the study. She will present the results of the study on Tuesday, Dec. 15, at the American Geophysical Union meeting in San Francisco. “But even a slight increase is a concern, especially in a place like Los Angeles, because you already have episodes of high ozone that you have to be concerned about, so you don’t want any increase.”
But it was at colder temperatures, below freezing, that it appeared the health impacts of E85 would be felt most strongly.
“We found a pretty substantial increase in ozone production from E85 at cold temperatures, relative to gasoline when emissions and atmospheric chemistry alone were considered, Read more
In Bats and Whales, Convergence in Echolocation Ability Runs Deep
January 27, 2010
Only some bats and toothed whales rely on sophisticated echolocation, in which they emit sonar pulses and process returning echoes, to detect and track down small prey. Now, two new studies in the January 26th issue of Current Biology, a Cell Press publication, show that bats’ and whales’ remarkable ability and the high-frequency hearing it depends on are shared at a much deeper level than anyone would have anticipated — all the way down to the molecular level.
The discovery represents an unprecedented example of adaptive sequence convergence between two highly divergent groups and suggests that such convergence at the sequence level might be more common than scientists had suspected.
“The natural world is full of examples of species that have evolved similar characteristics independently, such as the tusks of elephants and walruses,” said Stephen Rossiter of the University of London, an author on one of the studies. “However, it is generally assumed that most of these so-called convergent traits have arisen by different genes or different mutations. Our study shows that a complex trait — echolocation — has in fact evolved by identical genetic changes in bats and dolphins.”
Study Guide for Chapter 3 Test
January 27, 2010
1. Who is Robert Hooke?
2. Who is the scientist that discovered bacteria and protist by observing pond scum through a microscope?
3. Who are the three people who contributed to the cell theory? List them and explain their contributions.
4. State the three parts of the cell theory.
5. Compare and contrast the prokaryotes and eukaryotes.
6. What are the extremiphiles and where are they?
7. What is the most common type of bacteria and where is it found?
8. What is the fuction of the nucleus and what material will you find in it?
9. Why is the nucleolus found and what organelles are made in this organelle?
10 What is the function of the ER? Smooth and Rough.
11. Why are the mitochondria important?
12. What is the purpose of the Gogi bodies and wha organelle does this organelle make?
13. What organelle is responsible for you having seperate fingers and toes. What type of chemical does it release to aid in getting rid of waste in the cell?
14. What are vesicles and how are they different in plant cells compared to animal cells?
15. Where will you find the ribosomes in the cells? What is their function?
16. What is the cytoplasm and why does the Jell-o lab relate to this part of the cel?
17.What is the purpose of the cell membrane?
18. What is the difference between plant and animal cells?
19. Name the cell types that have cell walls.
20. What is the function of the chloroplast? In what cells will you find this organelle?
21. Why does the produce department in a supermarket usually have a sprinkler system?
22. Name some positive aspects of bacteria. What are some negative aspects of bacteria?
23. Complete this statement–cells make—-and —-make—–and organs make——and —make—-
24. Sing the Mitosis Song—All the Body Cells—-All the Body Cells —ooohhooohhhohohohhohhMitosis—5 bonus points for this study guide on the test!
Blog Jan.29th
January 24, 2010
Explain how chromatins turn into chromatids. What stage in the cell cycle does this occur?
Blog Jan. 28th
January 24, 2010
When learning about Mitosis, what part of the cell does the process occur?
Blog Jan 27th.
January 24, 2010
Explain the difference of how animals get their energy compared to plants.
Blog Jan. 26th
January 24, 2010
What are the major differences between plant and animal cells?
Blog Monday Jan. 25th
January 24, 2010
How are you different from a prokaryotic cell? How are your cells more specialized compared to a bacteria cell?
