09.Conrad+McDonald

7/2/12 Robert Hooke Robert Hooke, born on 1635, 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. The King at the time, (King Charles) asked for insect studies but Hooke went beyond and studied other things. When Hooke was looking at thin slices of cork under a compound microscope, he noticed that there were spaces contained by walls. He named these 'cells,' and in reality, he discovered the building blocks of all life. This led other scientists to look at this topic, which proved the theory that all living things are made up of cells. Now, we have a great understanding of cells, which allows us to treat diseases and learn more about our bodies, animals and plants.

Robert Brown Robert Brown was a Scottish Botanist, He was known for his extraordinary contributions to botany by leading the way in the use of the microscope. He also observed the Brownian law, which is how particles move in a space, which also helps explain the Kinetic theory. Brown's most important discovery was discovering a nucleus in plant cells, which was a major contribution to cell theory. This meant that he proved animal and plant cells are very close in structure. He intentionally found this, not like other scientists who stumble upon a discovery. For his acts, he won a Nobel prize. His discoveries were very significant then, and they are even more significant today. Today we greatly rely on information about plant cells to live, for e.g. many food crops are genetically modified, and they would not be able to do this without Brown's discoveries.

Homework- 11/3/2

tissue || Absorbs air and water. || 19/2/3
 * Plant structure || Function ||
 * Root || Fixes the plant in the soil, absorbs water and minerals and oxygen, store food materials. ||
 * Stem || Passes water and materials from the roots to the leaves through tubes called xylem. Transports food materials manufactured in the lives (glucose, sugar) to other parts of the plant through tubes called phloem. ||
 * Axillary bud || Evolves at the axel of a leaf, making growth for new stems. ||
 * Leaf || Found on plants, influences the process of photosynthesis. ||
 * Flower || Important in pollination, when pollen from the flower is transfered to a different flower. ||
 * Apical bud || (Terminal bud) The main growing point, found on the tip of the stem. ||
 * Photosynthetic
 * Vascular tissue || Water, dissolved materials, food and other organic substances pass through ||
 * Mesophyll tissue || Photosynthesis. They have chloroplasts which absorb the light that falls on the leaf. ||
 * Guard cells || They regulate the rate of transpiration by opening and closing the stomata thus preventing excessive water loss. ||
 * Epidermal cells || They are transparent, so it allows maxium light harvesting and protection. ||
 * Palisade mesophyll cells || Found within mesophyll, has the most exposure to sun. Collects light and maximizes surface area exposed to light. ||
 * Spongy mesophyll cells || Arranged loosely, allows air in between cells. Has fewer chloroplasts than palisade cells. ||

The dog and cow are vertebrates with different digestive systems, because of their difference in diet. The dog is a carnivore and the cow is a herbivore. This affects their whole digestive system, teeth, mouth, stomach/s and intestines. Dogs and cows have an oesophagus, to take food down through it. A difference is their stomachs. Dogs are  monogastrics, meaning they have one simple stomach. Cows are a part of a special group of herbivores, called ruminants. Ruminants are herbivores that have another way of dealing with the digestion of cellulose that they take in. They have a complex 4 chambered stomach to break down the cellulose, instead of a caecum, like other herbivores. Dogs also have a small caecum, which is rarely used because they do not ingest much cellulose. Cellulose is the substance found in the cell wall of plants, which no animal can break down/digest easily. Both the dog, and the cow have a small and large intestine. The difference is that a dog's intestines are much shorter than a cow's intestines. This is because cows are larger animals and take in a larger volume of food. This is why a long, rolled up intestine is useful because of its high surface area to ratio volume. In this way, the food's nutrients can get diffused out of the intestine and be digested. The faeces of a cow is much larger than a dog, which is also caused by its large SA:V.

02/04/2012 Radioisotopes, are elements that have a varied amount of neutrons in them, to their original number of neutrons. (matching the number of protons=atomic number) The isotopes which have a large number of neutrons to the n:p ratio, will be unstable, therefore releasing radiation in order to be stable. (gamma, beta and alpha rays) Radioisotopes are prominently used in the field of medicine. Radioactive products which are used in medicine are referred to as radiopharmaceuticals.

 Some uses of radioisotopes in medicine are to provide diagnosis on problems with a person's body and organs. The radioisotopes go into the body, and are able to give doctors readings, that they can study to diagnose the person. It works like how x-rays give images of our bones. Radioisotopes can also be used to treat some diseases that are diagnosed. This is called radiotherapy. Some harmful cells/matter in the body like e.g. cancer cells, can be weakened or destroyed with the radiation coming from the radioisotopes.

Neutron rich- excess in neutrons Proton rich- excess in protons

Examples- Cobalt-60. Has a half life of 5.27 years. Formerly used for external beam radiotherapy, now used more for sterilising equipment and medical products. It is good that the half life is long, so equipment that is daily used, can be re-sterilised only after a long time.

 Iodine-131. Has a half life of 8 days, so it does not stay in the body for too long, not exposing it to long term radiation. Used in treating thyroid cancer and in imaging the thyroid. Also in diagnosis of abnormal liver function, renal (kidney) blood flow and urinary tract obstruction. A strong gamma emitter, but used for beta therapy.

Strontium-89. Has a half life of 50 days. It is very effective in reducing the pain of prostate and bone cancer. Emits beta rays.

Iodine-131= It can be used to treat hyperthyroidism. The thyroid is a gland in the neck that produces 2 hormones that regulate the body's metabolism- (chemical process of converting food into energy) When the thyroid gland is overactive, it makes too much of these hormones, increasing metabolism to an unhealthy level. A small dose of Iodine-131 is swallowed. It is absorbed into the blood stream, and into the gastrointestinal tract. Concentrated from the blood by the thyroid gland. It emits beta rays, destroying the gland's cells. In a similar way, Iodine-131 can be used to treat thyroid cancer.

Pro- Useful in treatment~ It is especially helpful in the treatment of damaged/unhealthy/cancerous cells. As the cells divide, they become more susceptible to radiation, so when the specific area is targeted, the harmful cells are killed while the surrounding tissue un-damaged.

Useful in diagnosis~ Radioisotopes with a less harmful radiation, and a short half life are harmless to the body. They can be used to find the internal space within the body, allowing us to find problems faster. Isotopes enter the body orally, through an injection and also by inhaling it (gas). Once inside the body, it lets off amounts of radiation that can be read by a camera.

Con- Radiation can do more damage than good/side effects~ When used to treat, it can cause damage to the surrounding tissue. This can be very dangerous if it is in the brain or another important organ. Also, if the half life of the radio isotope is too long, the body will be exposed to radiation for a prolonged period of time, damaging cells and the results can be severe.

The want for nuclear energy grows~ Nuclear energy is a controversial topic because of concerns for human and environmental safety. The isotopes send off amounts of radiation which can cause severe damage to a human. Also, because of Uranium's long half-life, it can't be disposed off easily. It would destroy the environment it is in, and it might contaminate water supplies, causing widespread harm for us humans.

8/5/12 Conrad and Zoe Mosquitofish Scientific name- //Gambusia affinis//

Male



Female



The mosquitofish was introduced to Australia in 1925 from Central America. The intention was to control mosquito larvae, in an effort to reduce the likelihood of transmission of malaria, yellow fever, dog heart-worm and dengue fever. But, studies show that the mosquito fish does not reduce mosquito populations and diseases.

Mosquito fish are best adapted to live in warm, still or slow flowing water, but they can still survive in many types of water environments, from puddles to lakes. They can withstand a wide range of water conditions. Mosquitofish, (Gambusia) can also stand a wide range of temperatures, varying from <5 ̊C to 44 ̊C and salinities from freshwater to estuaries. They can also live in environments with poor access to oxygen. They receive oxygen by going up to the surface to gulp air in.

The mosquito fish also has adaptations to their outer body that helps them survive in their environment. The end of their snout is symmetrical so they are suited to prey in open water. Their eyes are small, allowing them to live in shallow water like puddles. Compared to their body, they have a large, forked, caudal fin, which along with its torpedo (stream line) shaped body and its small scales, makes it a strong, fast swimmer. Both sides are flat, so the fish is almost invisible from its front and rear sides, allowing it to feed without being seen. The fish is hump-backed, meaning it can also live in fast moving water like streams. The mosquito fish also has many adaptations to its colour, which help it survive. It has no markings, except for a false eye spot on its tail. This is so, if attacked, the predator will attack the tail, giving the mosquito fish a chance of escaping. The fish also has counter-shadowing, meaning it is dark coloured on the top and light coloured on the bottom. This is because the sea is darker at the bottom, so the fish will blend in, avoiding predators from the top. The sea is brighter at the top, so the mosquito fish will also avoid predators from the bottom.

They can live in warm, still, slow flowing water and many other water types, so they can easily live in any water environments. This will increase the species chance of survival. They can withstand water temperatures from <5 ̊C to 44 ̊C, so if there is any sudden temperature change in the water, they can still survive, while other species die off. Their diet includes a range of organisms like terrestrial, aquatic insects and mosquito larvae. This means they can survive on many organisms, so a fall in the organism's population will not affect them. Because they can live in any environments, they need to get adequate oxygen from the atmosphere. They do this by coming up to the surface and gulping in air.

The numerous adaptations of the mosquito fish greatly affects it's abundance and distribution. Because of their high ability to survive, their abundance is very high. Their high abundance affects their ecosystem, being a limiting factor of other species. Many native species are ceasing to survive because of the introduced mosquito fish, which unbalances the ecosystem's food web. The mosquito fish's many adaptations also increase the species' distribution. Because of its ability to live in many types of environments, it has a higher distribution. A factor that increases the abundance and distribution is the mosquito fish's extremely fast reproduction process and rates.