Science by Email 17 February 2012

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	17 February 2012
News: Sheep outstanding in their field By Patrick Mahony Domestic sheep have a high level of genetic diversity compared to other animals. By calling someone a sheep, you're suggesting they aren't an individual. But new research from CSIRO suggests that this might be unfair to sheep. Sheep were one of the first animals to be domesticated: evidence of herding sheep in the Middle East dates back to 13 000 years ago. Originally raised for their meat, over time sheep were bred for their wool and milk as well. Even before scientists discovered genes and DNA, farmers selectively bred their animals so that desirable qualities, such as size, were passed on to new animals. Today we know that these traits are encoded in genes. A problem with selectively breeding crops and livestock is that over many generations, it can cause their genetic diversity to decrease. Low genetic diversity is a problem because it can lead to things like deformities, lower birth rates and a weakened immune system, all of which threaten the survival of a breed or species. Researchers form CSIRO Livestock Industries investigated the genetic diversity of sheep all around the world. They discovered that sheep have high levels of genetic diversity, unlike other domestic animals such as some cattle and dog breeds. This high level of genetic diversity is due to frequent mating between sheep of different breeds to create breeds suited for a variety of purposes and environments. High genetic diversity means it is also easier to continue to improve and strengthen existing breeds. More information CSIRO link: Not the black sheep of domestic animals Cheetah Conservation Fund: Genetic diversity Selective breeding Careers link Ace Day Jobs: Geneticist
Try this: Super yeast You will need these materials.   Add 1/2 cup of hydrogen peroxide, a squirt of detergent and a few drops of food colouring to the bottle.   Dissolve the yeast in warm water.   Add the yeast mixture to the bottle and observe.   Safety: This activity uses hydrogen peroxide which can cause irritation. Read any safety instructions. Do not consume the chemicals used and wash your hands after completing the activity. See the CSIRO Education safety page for more information. You will need Safety glasses Plastic bottle Hydrogen peroxide (available in pharmacies) Yeast Funnel Detergent Measuring cup Measuring spoons Food colouring Warm water Tray What to do Put on the safety glasses. Place the bottle in the tray and add ½ cup of hydrogen peroxide. Add a squirt of detergent and a few drops of food colouring. Dissolve 1 teaspoon of yeast in 2 tablespoons of warm water. Add the yeast and water mixture to the bottle. What do you observe? What's happening? Hydrogen peroxide undergoes the following decomposition reaction: 2H2O2(l) → 2H2O(l) + O2(g) Hydrogen peroxide (liquid) → water (liquid) + oxygen (gas) Under normal circumstances this reaction happens slowly, with no obvious visible reaction taking place. Chemical reactions need some energy such as light or heat to start. The amount of energy required to initiate a chemical is called the activation energy. In the reaction above, the activation energy is relatively high, so the reaction proceeds slowly. Yeast is a microorganism that produces an enzyme called catalase. Catalase lowers the activation energy for the decomposition of hydrogen peroxide. The lower activation energy means the reaction occurs much faster. Oxygen gas is produced at a rapid rate, causing the detergent to foam up. The catalase itself isn't used up in the reaction. A chemical which lowers the activation energy for a chemical reaction, but doesn't react itself, is called a catalyst. Applications Catalysts have many roles in industry. Many beneficial chemical reactions have high activation energies, meaning they normally take a long time, or require high temperatures to take place. Catalysts are used to make reactions occur more readily, making it cheaper to produce the end product. As the catalyst doesn't react itself only a relatively small amount of catalyst is needed for large-scale industrial reactions. By Patrick Mahony Try another Science by Email activity exploring catalase More information Catalytic chemistry The science of catalysts and catalytic converters View the online version Quiz questions 1. Which fossil fuel provides most of Australia's electricity? 2. What are Saturn's rings made of? 3. Which is denser: saltwater or freshwater? 4. Professor David Bowman recently suggested introducing which of the following animals into northern Australia: a) elephants; b) water buffalo; c) lions; d) Komodo dragons? 5. Sweetlips and snapper are types of what? Did you know? New research shows that rivers and streams with high levels of surrounding vegetation have higher water quality and biodiversity than those that don't. Websites Watch it! Watch this video of pendulum waves. See it! See pictures of the Moon from NASA's Lunar Reconnaissance Orbiter Camera. Science at the Shine Dome teacher awards The Australian Academy of Science (AAS) is sponsoring a teacher from each state and territory to attend its annual Science at the Shine Dome conference in Canberra. This year the conference includes a symposium titled 'Antarctic Science: from Mawson's expedition to today', as well as seminars, presentations and education workshops. The award includes conference registration, return airfares, accommodation and food. Application forms can be found at the AAS website. Applications close Monday 5 March. Events Queensland: Megawatt exhibition Megawatt is a new exhibition at Sciencentre that is all about electricity. The exhibition includes information modules and interactive exhibits about generating and using electricity. It also features exhibits on renewable and sustainable electricity. Megawatt runs from 19 February to 2 October. For more information head over to the Sciencentre website. Elements, Sunday 19 February at 7.30 am on Network Ten Every science classroom has one, but how and why was the periodic table of elements created? What's so special about iron, neon, calcium, tungsten, magnesium and chromium? Join Dr Rob as he takes aim at the periodic table and SCOPES out all the science behind elements, once again proving that the ordinary becomes extraordinary, under the SCOPE. Next episodes: Thursday 23 February: Copper Sunday 26 February: Team sports Want to have your own episodes of SCOPE to watch whenever you feel like it? Click here to download them directly into your iTunes folder, or go here to download iTunes. Charges apply. Quiz answers 1. Most of Australia's electricity comes from the fossil fuel coal. 2. Saturn's rings are mainly made of water ice, with some dust and rock. 3. Saltwater is denser than fresh water. 4. David recently suggested introducing a) elephants and d) Komodo dragons into northern Australia to control invasive species. 5. Sweetlips and snapper are types of fish. Research from James Cook University suggests that these fish are picky when it comes to choosing a habitat. Science by Email is a CSIRO publication. The Department of Agriculture, Fisheries and Forestry and bankmecu are proud partners of Science by Email. Editor: Mike McRae | Manage your subscription | FAQ

 

 

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