Patterns+in+Nature+liz


 * Cells Tissues Organs Systems** - in book

**Comparative Anatomy and Physiology of Digestion in Vertebrates**

 Question 1- in book Question2-


 * Photosynthesis**

Plant cells are autotrophs, they are ‘self-feeding’ and [|make their own nutrients] through photosynthesis therefore they contain chlorophyll. Animal cells are heterotrophs, meaning they feed on other things, they have to outsource their nutrients, eating autotrophs (or other heterotrophs that eat autotrophs). The materials required for photosynthesis are carbon dioxide, water and light. Photosynthesis is at the base of the food chain. Autotrophs rely on photosynthesis for nutrients and heterotrophs rely on autotrophs or other heterotrophs as a food source. Light energy is absorbed into the chlorophyll in the chloroplasts which use it to make chemical energy; some of this energy is used to split water molecules into hydrogen and oxygen. Hydrogen from the light energy stage is used to form sugars when combined with carbon dioxide; to do this some energy from the light energy stage is used. Quiz: all answers correct Many things affect the rate of photosynthesis including light levels, temperature, availability of water, availability of nutrients. All factors that are required for photosynthesis will affect the rate at which photosynthesis acts.

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 * Gaseous exchange and body transport systems**
 * **Circulatory System** || **Respiratory System** || **Excretory System** ||
 * All cells in the body need to have oxygen and nutrients, and they need their wastes removed. These are the main roles of the circulatory system. The heart, blood and blood vessels work together to service the cells of the body. Using the network of arteries, veins and capillaries, blood ferries carbon dioxide to the lungs (for exhalation) and picks up oxygen. From the small intestine, the blood gathers food nutrients and delivers them to every cell. || The main role of the Respiratory System is the inhalation of fresh oxygen (O2) needed by the body's cells and the exhalation of waste carbon dioxide (CO2). It also helps maintain body temperature and eliminate excess water from the body. The Respiratory system is dependent on the proper functioning of the circulatory system as the O2 and waste CO2 are carried in the blood stream. || The job of the excretory system is to remove various produced by the body. The removal is known as excreation. It is important for the body to remove these various waste, also known as toxic, because toxic build up can lead to servere death. ||
 * < **Insect** ||< **Fish** ||< **Frog** ||< **Mammal** ||
 * < __Tracheal system__- network of tubes located throughout the body through which air passes

__Spiricals__- holes in the respiratory system located on the abdomen, openings into internal tubes

__Tracheae__- largest branch in the body, leads onto smaller branches, tracheoles

Air enters the spiricals, travels along the tracheae and into the tracheoles; here the oxygen diffuses into the cells. ||< __Gills-__ folding of the body wall supported by bony gill arches

__Gill filaments-__ fleshy part of gills where oxygen is absorbed from the water into the blood stream

Fish breathes in water which flows out over the gills. Blood flows into the gill filaments, oxygen from the water flows in and carbon dioxide returning from the body flows out with the water. ||< Frogs have small lungs which they fill with air by gulping. The frog lowers the floor of its mouth, closing the path to its lungs, and then it inhales through its nostrils. They then close their nostrils and open the path to their lungs and raise the floor of their mouth to push air into the lungs. They then let out the carbon dioxide through their mouths. Carbon dioxide can diffuse through the surface of their skin. For clearer understanding refer to Figure 2.4.5 page 132 ||< __Trachea-__ entrance pipe to your lungs

__Pharynx-__ where food and air meet

__Larynx-__ closes entrance to your trachea, where the epiglottis and voice box are

__Bronchi-__ pathways leading to lungs

__Alveoli-__ air sacs where oxygen diffuse into blood stream through capillaries

Air is breathes in the nose and mouth, it then travels down the trachea to the pharynx where the larynx stops food from continuing down the trachea and air continues to the bronchi. The air travels into the lungs via the bronchi and down into the alveoli where oxygen is diffused into the capillaries to travel around to the cells through the blood stream and carbon dioxide is diffused into the alveoli to be breathed out. ||

[|http://www2.gsu.edu/~bioasx/closeopen.html]
 * **Closed Circulatory System** || **Open Circulatory System** ||
 * Vertebrates, and a few invertebrates, have a closed circulatory system. Closed circulatory systems have the blood closed at all times within vessels of different size and wall thickness. In this type of system, blood is pumped by a heart through vessels, and does not normally fill body cavities. || The open circulatory system is common to molluscs and arthropods. Open circulatory systems (evolved in crustaceans, insects, mollusks and other invertebrates) pump blood into a hemocoel with the blood diffusing back to the circulatory system between cells. Blood is pumped by a heart into the body cavities, where tissues are surrounded by the blood. ||

Intro · Study of transport systems helps us to understand there uptake of various types of substances and their passage through plants, · This knowledge can be used to develop fungicides, pesticides, growth regulators, etc. · Also helps us diagnose disease and developing medicines. · Radioactive tracers help us do this Radioactive isotopes · Isotopes are atoms of the same elements which contain the same number of protons but different number of neutrons · Radioactive isotopes are isotopes which are unstable (that is, their nucleus does not hold together well and therefore breaks down, making the compound radioactive) and undergoes radioactive decay while emitting heat and radiation · Radioactive isotopes are used to study organisms, to diagnose and treat disease,to sterilize medical instruments and food, to produce heat for electricity, to monitor steps in industrial processes · Many practical applications include radio-carbon dating, radioactive material builds up in an object over time and then decreases due to radioactive decay when the plant dies, this can be used to gain a rough date for something in ancient history Tracers · Common application for radioactive isotopes is tracers, which is a radioactive isotopes whose pathway can be followed, commonly used in the medical field and when studying plants and animals · They can be used within a plant or animal to follow the movement of certain chemicals. · In medicine, they have many uses, such as imaging, being used as tracers to identify abnormal bodily processes, testing of new drugs and conducting research into cures for disease. · Plants take up phosphorus by the roots, so by adding radioactive phosphorus to fertilizer and then measuring the rate at which radioactivity appears in the leaves, we can determine the rate of uptake of phosphorus from the soil. This can help biologists identify plant types which absorb phosphorus quickly or slowly. · Carbon-14 was used by Melvin Calvin (after whom the Calvin cycle is named) to map the path of carbon in photosynthesis and for which he won the Nobel Prize in 1961. It is useful as a radioactive tracer in plants as carbon is taken in by the plant in the form of carbon dioxide and is then incorporated into the carbon containing compound, glucose, and other carbohydrates (eg. starch). <span style="font-family: Symbol; mso-bidi-font-family: Symbol; mso-fareast-font-family: Symbol; msobidifontfamily: Symbol; msofareastfontfamily: Symbol; msolist: Ignore;">· To measure pesticide levels, a pesticide can be tagged with a radioisotope such as chlorine-36, and this is applied to a field of test plants. Over a period of time, radioactivity measurements are made. Estimates can then be made about how much accumulates in the soil, how much is taken up by the plant and how much is carried off in run-off surface water. <span style="font-family: Symbol; mso-ansi-language: EN-US; mso-bidi-font-family: Symbol; mso-fareast-font-family: Symbol; msoansilanguage: EN-US; msobidifontfamily: Symbol; msofareastfontfamily: Symbol; msolist: Ignore;">· Radioactive isotopes and radioactive tracers are used in the medical field to identify abnormal bodily processes, this works because some compounds gather in certain areas of the body, when a compound doped with a radioactive element is injected into a patient a special camera is used to take pictures of organs and a doctor can make a diagnosis. <span style="font-family: Symbol; mso-ansi-language: EN-US; mso-bidi-font-family: Symbol; mso-fareast-font-family: Symbol; msoansilanguage: EN-US; msobidifontfamily: Symbol; msofareastfontfamily: Symbol; msolist: Ignore;">· For example iodine concentrates in the thyroid, phosphorus concentrates in the bones, potassium concentrates in the muscles Positron Emission Tomography (PET) <span style="font-family: Symbol; mso-ansi-language: EN-US; mso-bidi-font-family: Symbol; mso-fareast-font-family: Symbol; msoansilanguage: EN-US; msobidifontfamily: Symbol; msofareastfontfamily: Symbol; msolist: Ignore;">· Measures important body functions like blood flow, oxygen use, and glucose use, doctors use information to check functioning of organs and tissues <span style="font-family: Symbol; mso-bidi-font-family: Symbol; mso-fareast-font-family: Symbol; msobidifontfamily: Symbol; msofareastfontfamily: Symbol; msolist: Ignore;">· Radionuclides used in PET scanning are isotopes with short half–lives, such as carbon-11 (~20 min), nitrogen-13 (~10 min), oxygen-15 (~2 min) and fluorine-18 (~110 min). These radionuclides are added into compounds normally used by the body such as glucose (or variations of glucose), water or ammonia. Such labelled compounds are known as radiotracers. In some situations, the patient is required to breath oxygen gas labelled with oxygen-15. <span style="font-family: Symbol; mso-bidi-font-family: Symbol; mso-fareast-font-family: Symbol; msobidifontfamily: Symbol; msofareastfontfamily: Symbol; msolist: Ignore;">· The radionuclides used in PET decay by a process called positron emission. A positron is the antimatter version of the electron. When a positron meets an electron, an annihilation event occurs, resulting in the production of two gamma rays. The two emitted gamma rays travel in opposite directions. <span style="font-family: Symbol; mso-ansi-language: EN-US; mso-bidi-font-family: Symbol; mso-fareast-font-family: Symbol; msoansilanguage: EN-US; msobidifontfamily: Symbol; msofareastfontfamily: Symbol; msolist: Ignore;">· The PET scanner picks up these gamma rays and generates a map of where these events are occurring, if it’s used in conjunction with a CT scan a more complete picture of how well an organ is functioning can be made <span style="font-family: Symbol; mso-ansi-language: EN-US; mso-bidi-font-family: Symbol; mso-fareast-font-family: Symbol; msoansilanguage: EN-US; msobidifontfamily: Symbol; msofareastfontfamily: Symbol; msolist: Ignore;">· PET requires the patient to be injected with radioactive substance then the scanner shows where the radioactive substance has been transported; this means the scanner is showing metabolic processes as opposed to showing structures and parts of the body. <span style="font-family: Symbol; mso-bidi-font-family: Symbol; mso-fareast-font-family: Symbol; msobidifontfamily: Symbol; msofareastfontfamily: Symbol; msolist: Ignore;">· Due to the short half-lives of most radioisotopes, the radiotracers must be produced using a cyclotron (a type of particle accelerator) and radiochemistry laboratory that are close to the PET imaging facility. The half-life of fluorine-18 is long enough such that fluorine-18 labelled radiotracers can be manufactured commercially at an off-site location. <span style="font-family: Symbol; mso-bidi-font-family: Symbol; mso-fareast-font-family: Symbol; msobidifontfamily: Symbol; msofareastfontfamily: Symbol; msolist: Ignore;">· In radiotherapy (also called radiation therapy), gamma radiation emitted by cobalt -60 is used in the treatment of cancer. The radiation will destroy cancerous cells and shrink tumors. Radioactive tracers are used to check the function of body organs: a) Iodine -131 or strontium -89 is injected into a patient’s body or taken orally to detect damage to the thyroid gland b) Sodium -24 is injected into blood vessels to detect to clotting of blood during a head injury c) Barium -138 or iodine -131 are injected into a patient’s body to detect brain tumors. <span style="font-family: Symbol; mso-bidi-font-family: Symbol; mso-fareast-font-family: Symbol; msobidifontfamily: Symbol; msofareastfontfamily: Symbol; msolist: Ignore;">· Phosphorus-32 can also be used to detect and treat cancers as it has been found that cancer cells accumulate more phosphorus than normal cells.
 * Radioactive Tracers **