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B7.5 - New technologies
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- 1Where are microorganisms ususally grown, when making them on a huge scale?in fermenters
- 2What extract from calves stomachs is used in cheese production and what 'active ingredient' does it have so to speak?rennet contains the enzyme chymosin
- 3What is lignin and how does it relate to biofuels?Lignin is a tough fibre found in plant cells, making them hard to digest. But an enzyme is being developed which could make this and cellulose break down, which could mean stalks and leaves could be used as fuel - crop waste instead of normal crops.
- 4What type of fungi is Quorn?A single-celled protein.
- 5DNA occurs in two places in bacteria cells - name both.A circular chromosome and in 'plasmids' or extra little rings of genes.
- 6What is it called when the genes of an organism are changed?genetic modification (GM)
- 7What example is there of how GM modification of bacteria has produced a really useful medicine?insulin is produced by bacteria that is exactly the same as human insulin
- 8How would genetic modification in plants work?Crops could become resistant to some herbicides, which would then kill weeds without damaging the crop.
- 9What is needed to carry the gene into the cell and what are used?The vector used is a plasmid.
- 10What four stages are there to genetically modifying a bacteria cell with a human gene, including what is used to get the plasmid into the cell?First enzymes cut out a human gene, then a plasmid is taken from a bacterium, then enzymes cut out a section of the plasmid and replace it with the human gene, then the plasmid is inserted into a bacteria cell using bacteriophages that are viruses that can infect bacteria.
- 11What is it called when a gene is active in a cell?It's expressed.
- 12What is it called when fragments of DNA are grouped, so to speak?gel electrophoresis
- 13What is used to multiply the amount of DNA found to make it usable?A PCR or polymerase chain reaction.
- 14What four things is PCR used for?To copy DNA obtained from a crime scene when it's in a very small quantity, to copy a gene for GM, to make gene probes and to look more closely at an area of study.
- 15How can nanotechnology be used in relation to food?Silver nanoparticles added to the plastic used to make food wrap or food boxes reduce contamination by microorganisms as they have antibacterial properties.
- 16What three things can trigger special nanoparticle food wrapping films to change colour?If antibodies in the film react with bacteria in the food, or if nanoparticles in the film react to changing levels of oxygen (this indicates the film has ripped) or if fruit ripens and releases gases that react with nanoparticles in the film.
- 17Why does nanosilver work?The nanosilver particles are small enough to get inside an animal cell, where they react to form silver ions, which are about the same size as a sodium ion. This disrupt normal cell activities, causing them to die.
- 18What does it mean when our cells are specialized for a particular function?They're differentiated.
- 19What area of the heart controls the muscle contractions?The pacemaker does.
- 20What three things can go wrong in a heart?Your arteries can get clogged up and you can have a heart attack, or your heart valves can become stiff or worn, or you can end up with an irregular heart beat because of a faulty pacemaker.
- 21What disadvantages are there of human/animal donor valves and of artificial valves?Human valves can be rejected by the immune system, whilst artificial valves can cause damage to blood cells and make a regular clicking sound.
- 22What kind of object is an artificial heart valve?A product of biomedical engineering.
- 23What do artificial pacemakers do?Monitor your heart beat and stimulate your heart to beat in a natural rhythm.
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- Cambridge IGCSE Biology Fichas sobre B7.5 - New technologies, creado por franimal el 15/06/2014.
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- franimal
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