Category Archives: Student Posts

Fox control in Victoria

red fox

By Chris and Catherine

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…

  • Lethal baiting
  • Shooting
  • Trapping
  • Den fumigation
  • Den destruction

Exclusion fencing is another effective strategy but it is extremely expensive and un-suitable for farmers.

Physiological Adaptations to cold temperatures

wood_frog

Image Source – Cold-tolerant Wood Frog

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

Image Source – Winter vegetable garden

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.

Physiological adaptations for Survival

budgerigars2

Budgerigars – Melopsittacus undulatus

The following posts are by students, about the structual, functional and behavioural features of vertebrates that live in arid environments, that enable them to balance their water requirements.

Structural

-Small size of the budgie means that the water requirements are minimal.

-Budgerigars save water by excreting thier waste as nitrogenous waste.

Behavioural

– the budgies will huddle together in dry weather to reduce water loss by reducing thier movement and loss of water through sweat glands.

-they eats seeds with a high water content

Functional

– the budgies excrete most of their nitrogenous waste as uric acid which can be contolled as to how dry or wet it is depending on water availability

Euro or wallaroo

Euro or wallaroo – Macropus robustus

Structural

  • have bare muzzles
  • have large ears

Functional

  • can obtain all necessary water from food during dry spells

Behaviour

flounder

Flounder – Platichthys flesus

Structural features of the flounder

  • The flouder has a a minute body cavity that helps the flouder stay on the bottom of the ocean.
  • Lack of air bladder helps the flouder to stay on the bottom of the ocean.
  • Eyes on the up side of their body helps to spot pray and predators.
  • The top side of the flouders is dark and the bottom side is light.
  • They have strong teeth and jaw.
  • They have a large mouth.
  • Pusterior fin flatter and broader to swim faster and helps to swim on side

Functional features of the flounder

  • tolerance for low salinity
  • has diluted urine in fresh water
  • concntrated urine in salt water

behavioural features of  flounder

  • Change color of skin to match surroundings to hide from predators
  • bury themselves in the sand to hide from predators or to catch pray
  • change shape to help find food
  • go from river to sea

Revision of Unit 1: Cells in Action

animal cell cake

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.

Chapter 1 (Cell Discovery and Exploration): Stephanie and James

Chapter 2 (Cell Structure and Function): Chris and Melissa

Chapter 3 (Composition of Cells): Charlotte and Catherine

Chapter 4 (Cell replication – Mitosis and Meiosis): Monique and Chloe