All IB Biology Processes Latest Update with Verified Solutions

All IB Biology Processes Latest Update with Verified Solutions Stem Cell Therapy 1. triggering the differentiation of stem cells into desired cell type 2. surgical implantation of differentiated cells into patients tissue 3. suppression of immune system so they do not get destroyed 4. monitoring so they are not cancerous eg. Stagardt's Disease (old retina cells -- new retina cells) Leukemia (bone marrow transplant) Somatic cell nuclear transfer - creation of embryonic clones by fusing a diploid nucleus - more embryos created than needed Nuclear reprogramming - change in gene expression to transform into another cell Miller-Urey Experiment - recreation of conditions of pre-biotic Earth 1. water boiled to reflect high temperatures of pre-biotic Earth 2. water vapour mixed with a variety of gases to create a reduced atmosphere 3. mixture exposed to an electrical discharge 4. mixture then allowed to cool and left for about 1 week 5. After, it is analysed to find traces of simple organic molecules Friedrich Woehler -falsified vitalism - by artificially making urea by heating inorganic salt (ammonium cyanate) Water vs Methane - water is polar and can form intermolecular hydrogen bonds - methane is non-polar and only weak bonds - water has a higher MP and BP - water has a higher heat of vaporisation - water has a higher heat of fusion Water as a coolant 1. liquid - vapour requires an input of energy 2. energy comes from the skin surface when hot therefore cooling 3. effective coolant because it absorbs lots of heat due to high specific heat capacity Surface tension of water - due to cohesion of water 1. hydrogen bonding between water molecules allows liquid to resist low levels of external force (gravity) 2. helps in smaller organisms, to move along surface Capillary action of water - due to adhesion 1. attraction to charged or polar substances allows water to flow in opposition of gravitational forces - helps in transpiration Regulation Blood Cholesterol Levels - saturated fats increase LDL levels within the body, which raises cholesterol levels - trans fats increase LDL levels and decrease HDL, significant increase in cholesterol - cis fats increase HDL levels, lowering blood cholesterol Protein Structure Primary Structure - order of amino acid sequence - determines way the chain will fold Secondary Structure