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Cell Theory - Discuss the theory that living organisms are composed of cells.

Extracts from this document...

Introduction

IB Biology Syllabus Unit 1 1.1 Cell Theory (3h) 1.1.1 Discuss the theory that living organisms are composed of cells. 1.1.2 State that a virus is a non-cellular structure consisting of DNA and RNA surrounded by a protein coat. A virus is a non-cellular structure consisting of DNA and RNA surrounded by a protein coat 1.1.3 State that all cells are formed from other cells. All cells are formed from other cells 1.1.4 Explain three advantages of using light microscopes. * Colors of material from specimen can be seen * Living material can be studied and larger field of view * Cell activities and movement can be studied 1.1.5 Outline the advantages of using electron microscopes. Electron microscope * Greater resolution so smaller structures can be seen * gives interior/3-D view 1.1.6 Define organelle Organelle - a small body with a specialized structure within a cell for a specific function 1.1.7 Compare relative sizes of molecules, cell membrane thickness, viruses, bacteria, organelles and cells, using appropriate SI units. Size comparison: * molecules - 1 nm * macromolecules - 100 nm * cell membrane - 10 nm * virus - 75 nm * bacteria - 1 ' m * organelle - 3 ' m * cell - 10 ' m 1.1.8 Calculate linear magnification of drawings. Magnification = size of image / size of specimen 1.1.9 Explain the importance of the surface area to volume ratio as a factor limiting cell size. The rate of metabolism of a cell is a function of its mass/volume, whereas the rate of exchange of materials and energy is a function of its surface area. Volume is a cubed function while surface area is a squared function. Therefore, volume increases more as an abject grows in size. The greater the size of the cell (the more living cytoplasm it has), the lover the ratio of surface area (cell membrane) ...read more.

Middle

* enters ecosystem as light (usually) * leaves ecosystem as heat * nutrients are matter, cannot disappear, therefore are recycled 4.1.14 Draw the carbon cycle to show the processes involved. SEPARATE PAPER 4.1.15 Explain the role of saprotrophic bacteria & fungi (decomposers) in recycling nutrients. Saprotrophs: release nitrogen for use by plants 4.2 Populations (3h) 4.2.1 Outline how population size can be affected by natality, immigration, morality and emigration. Natality * population increases as new members are born * balanced by mortality Immigration * population increases as new members move in * balanced by emigration Mortality * population decreases as old members die * balanced by natality Emigration * population decreases as old members move out * balanced by immigration 4.2.2 Draw a graph showing the sigmoid (S-shaped) population growth curve. SEPARATE PAPER 4.2.3 Explain reasons for the exponential growth phase, the plateau phase and the transitional phase between these two phases. Exponential growth phase- population grows exponentially to limit of food supply Plateau phase- food supply can support a limited number of organisms Transitional phase- excess organisms die 4.2.4 Define carrying capacity. Carrying capacity - the maximum density of organisms that a particular environment can sustain in perpetuity 4.2.5 List three factors which set limits to population increase. 1) food supply 2) predator population 3) disease 4.2.6 Define random sample Random sample - an unbiased survey on selected members of a population 4.2.7 Describe on technique used to estimate the population size of an animal species based on a capture-mark-release-recapture method. * capture a preset number of animals from one area * mark these animals with a distinguishing visual characteristic * release the animals to the wild * several days later, capture another preset number of animals * count the number of recaptured marked animals Population size = (recapture / capture) * (10000 / recapture) 4.2.8 Describe one method of random sampling used to compare the population numbers of two plant species, based on quadrat methods. ...read more.

Conclusion

Excretory products: Plants: O2 Animals: CO2 / nitrogenous compounds 12.1.3 Discuss the relationship between the different nitrogenous waste products and habitat in mammals, birds, amphibians and fish. SEPARATE PAPER 12.2 The Human Kidney (4h) 12.2.1 Draw the structure of the kidney including cortex, medulla, pelvis, ureter and renal blood vessels. SEPARATE PAPER 12.2.2 Draw the structure of a glomerulus and associated nephron. SEPARATE PAPER 12.2.3 Explain the process of ultrafiltration (also called glomerular "filtration") including blood pressure, fenestrated blood capillaries, and basement membrane. Ultrafiltration: * blood pressure pushes blood through glomerulus * amino acids / glucose / H2O / Na+ / Cl- reabsorbed into efferent arteriole * NH2 / H2O / Na+ / Cl- descend into loop of Henle * H2O / Na+ reabsorbed * tubular excretion occurs in distal convoluted tube - large molecules enter for excretion * collecting duct carries wastes to renal pyramid 12.2.4 Define osmoregulation. Osmoregulation: control of water balance of the body brought about largely by the kidney 12.2.5 Explain the reabsorption of glucose, water and salts in the proximal convoluted tubule including the role of microvilli, osmosis and active transport. SEPARATE PAPER 12.2.6 Explain the roles of the loop of Henle, medulla, collecting duct, ADH in maintaining water balance of the blood. SEPARATE PAPER 12.2.7 Compare the composition of blood in the renal artery and renal vein, and glomelular filtrate and urine. Blood composition: * renal artery: blood with wastes * renal vein: blood without wastes * glomerular filtrate: amino acids, glucose, Na+, Cl-, NH2, urea, nutrient excess, nitrogenous waste, [H+], H2O * urine: wastes - urea, Na+, Cl-, NH2, H2O, large molecules 12.2.8 Outline the structure and action of kidney dialysis machines. Kidney dialysis machine: * blood from artery goes to dialysis chamber * dialysis tubing allows nitrogenous wastes to diffuse from blood * blood returns to vein * fresh dialysis solution replaces used dialysis solution in dialysis chamber ...read more.

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