The Red Fox (Vulpes vulpes) is a pest which was introduced to Australia from Europe in 1855 for hunting purposes. Populations of foxes in the wild became established in 1870. It took less than 100 years for the foxes to spread across most parts of Australia.
The red fox has had a major, negative impact on Australia since its population increased to uncontrollable proportions. The Red Fox has played a major role in the decline of the population of ground-nesting birds, small mammals and reptiles. It is also thought to be the main cause of population decrease for many threatened species. The Red Fox also poses an economic threat to many farmers by preying on their vulnerable farm stock such as lambs and chooks. It is also a carrier of rabies, a disease which affects mostly dogs but can be passed on to humans, livestock and native mammals.
The government has employed tactics such as bounties in order to reduce the population of the Red Fox. In 2002 the government introduced 24 collection points were people could hand in fox tails in order to receive a $10 reward. In the first year there was 150 822 fox tails handed in. The program was evaluated after the first year and found that the program was ineffective in reducing the fox numbers and so the program was scrapped in mid 2003.
The most effective methods of culling Red Foxes are…
Exclusion fencing is another effective strategy but it is extremely expensive and un-suitable for farmers.
Wood frogs (Rana sylvatica) are found in the northern parts of North America where the temperature can get very cold. When the wood frog experiences chilly conditions, a chemical signal is sent through it’s boy which prepares the frog to be frozen. The frog can remain frozen solid for the whole winter. The frog’s heart stops beating during this time also. It feels rock hard and looks dead but is not. When the weather starts to get warmer in the spring, the frog thaws out just in time for mating season. The frog can stay frozen without dying because of the way it stores glucose, which lowers the freezing point of water. The frog is able to build up the concentration of glucose in it’s cells, so that the cytoplasm doesn’t freeze, even when the interstitial water freezes. Two-thirds of the water in the frog’s body can freeze into ice crystals.
(Student post from an article in “Scientriffic” by Priyanka Shewpersad)
Winter vegetables, such as broccoli, cabbage, cauliflower and brussel sprouts, are also frost-tolerant. These plants have genes that allow “antifreeze proteins” to be produced, which prevent the plant cells from being damaged by frost.
This is a model of an animal cell made from cake showing the different organelles of a typical cell. The nucleus is shown by the freckle, mitochondrian was shown by the purple jelly beans, the lysosomes were the yellow jelly beans, the centrioles was the musk sticks which were then placed on the cytosol (icing), the vaccuole was shown by two freckles placed upside-down, the endoplasmic reticulum was made with yellow snakes and the rough endoplasmic reticulum was made with yellow snakes with 100’s and 1000’s laces on top to make the ribosomes and for the golgi compex was made by placing a pink snake on the icing.
This activity was enjoyed by the year 11 biology group. Making a model of a cell meant that we could relate to what a real one looked like. This made it easier to remember the names of parts of the cell and what their function was.
We observed some cells in class with light microscopes. We looked at plant and animal cells. The most interesting ones were sunflower stem and root tip tissues becasue we could see the cells really clearly and they looked cool. Some funny ones were rat testicles and frog bladder.