06.Mathew+Holt

7th February, 2012.
 * Who is he?
 * What was his job?
 * What did he contribute to cell theory?
 * Why was his contribution so important?

Robert Brown: Robert Brown was born on the 21st of Decemeber, 1773, in Montrose Scottland and died on the 10th of June 1858. He first studied medical studies at Edinburgh University in 1792. In 1801 he went as a naturalist on one of Matthew Flinders's expeditions to Australia, returning in 1805 to England with valuable collections. Brown was a botanist and a Plant geographer. A Botanist is a biologist specialising in the study of plants. This is why Brown had the understanding and interest in the discovery he made towards cell theory. Brown contributed to the cell theory, with the discovery of the cell nucleus. In 1827, discovered the cell nucleus in 1831, and was the first to recognize gymnosperm as a distinct angiosperm. His studies of several plant families and of pollen were also notable. His significance to his findings was that without his discovery of the nucleus cell and cytltoplasmic streaming there would be no knowledge or will be later knowledge of these biological concepts.

Robert Hooke: Robert Hooke was born on the 28th of July 1635. He was a self educated English physicist and biologist who made many important discoveries and inventions. When he was just 26, he joined the Royal Society For Scientists. Hooke was ordered to study insect by King Charles but Hooke took his studies and reasearch further to a point where he discovered 'cells'. Hooke made this discovery by looking at thin slices of cork under a compound microscope (the best microscope in his time), and noticed that there were empty spaces contained by walls and named them cells. Hooke discovered the law of elasticity, known as Hookes law. Hookes discovery led other scientists to look at this topic, which proved the theory that all living things are made up of cells. Without Hookes first discovery, other scientist in the future would not have been able to make further discoveries in cells and we would not have the information and medicines we have today.

**__19/3/12-__ In class work Digestive Systems** VS Comparison : Similarities- EsophagusSmall intestineLarge intestine mouths Liver Differences- A cow has a rumen A dog has a caecum A cow doesn't have a caecum Dog has a pelvic boneDog has a spleen 1. Herbivorous have a 4 compartment digestive system (the rumen, reticulum, omasum, and abomasum) this is to help them digest green leaves and vegetation into organic acids and absorb the acids to get energy. The 4 compartment stomach is essential for them to do this. Carnivorous do not have a 4 chamber stomach, but they do have more digestive juices and enzymes (specially stronger and more effective protease enzymes to digest proteins) and really strong stomach acids to digest meat and bones.

2. Herbivores got their appendix filled with a bacteria to digest cellulose. They give out cellulase to digest it. Herbivores have a rather bigger appendix because of this. Carnivores, of course, don't need this and hence do not have the bacteria in their appendix.

3. Herbivores don't have the front teeth on their upper jaw, instead they have a tough, fibrous pad. This helps them to hold onto the top of fresh grass and graze it by cutting it evenly. The pad makes the gripping and cutting much much easier. Carnivores do not have this pad, but they got sharp front teeth to help them scrape the flesh off bones and to nibble at meat.

** What are radioisotopes used for in medicine? **

 * ====Nuclear medicine uses radiation to provide diagnostic information about the functioning of a person's specific organs, or to treat them. Diagnostic procedures are now routine. ====
 * ====Radiotherapy can be used to treat some medical conditions, especially cancer, using radiation to weaken or destroy particular targeted cells. ====
 * ====Tens of millions of nuclear medicine procedures are performed each year, and demand for radioisotopes is increasing rapidly. ====


 * Provide 3 examples of a radioisotope and list where it is used. **

 I131 (iodine 131) radioactive for thyroid watching in medicine  14C (carbon 14) for dating prehistoric findings  Ra 226 ( radium 226 ) and Co60 cobalt 60 for treating cancer


 * List the pros and cons of using radioisotopes in medicine. **

 pros:useful in diagnosis, useful in treatment  cons:can have negative side effects, contributes to demand of nuclear power

__**The Mosquito Fish in Australia **__
Scientific name: Gambusia affinis

Diagram:



Why was the mosquito fish first introduced?: Mosquitofish were introduced by military and local councils to control mosquito populations, however there has been no evidence that gambusia has had any effect in controlling mosquito populations or mosquito-borne diseases in Australia in 1925.

What are some adaptations and how it improves its chances of survival?: Certain thermal adaptations have allowed them to live in places from 55° North to 44° South, expanding their natural range. They have a resistance to a wide variety of pollutants, including organic waste, heavy metals, insecticides, herbicides, rotenone, phenol, and radiation. Ichthyologists believe the reason for low mosquito levels in areas populated by gambusia is not because of the fish, but rather the insecticide in the water killing the larvae. Mosquitofish occur in clear and muddy waters, primarily in warm still or slow flowing water with surface vegetation. They prefer water temperatures between 25°C and 38°C, but have been known to survive under ice and in temperatures up to 44°C. Like Carp and Goldfish, the Mosquitofish can tolerate a wide range of salinities, all of these strategies allowing it to be highly competitive and widespread.

What has this done to the ecosystem and how has this influenced the distribution and abundance of the mosquito fish?: Currently, known populations of wild mosquitofish occur in every state and territory except the Northern Territory, and they are found in swamps, lakes, billabongs, thermal springs, salt lakes, and ornamental ponds.Mosquitofish have harmed native fish populations in many ways. By consuming algae-eating zooplankton, they increase the chances of algae blooms in the water, reducing the water quality. They are very aggressive, and tend to attack other fish and nip their fins, leading to infection or death. Mosquitofish have an extremely effective breeding strategy, being live bearers, out compete native fish especially in degraded systems and harass and nip the fins of other small fish and tadpoles. Mosquitofish has been implicated in the decline of several small native fish species. Mosquitofish are very aggressive and probably outcompete native fish for food and shelter. The decline of the soft spined rainbow fish in Queensland has been attributed to Mosquitofish. They may also prey on native fish eggs and fry.