B7.5 - New technologies

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Cambridge IGCSE Biology Flashcards on B7.5 - New technologies, created by franimal on 15/06/2014.
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Flashcards by franimal, updated more than 1 year ago
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Question Answer
Where are microorganisms ususally grown, when making them on a huge scale? in fermenters
What extract from calves stomachs is used in cheese production and what 'active ingredient' does it have so to speak? rennet contains the enzyme chymosin
What 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.
What type of fungi is Quorn? A single-celled protein.
DNA occurs in two places in bacteria cells - name both. A circular chromosome and in 'plasmids' or extra little rings of genes.
What is it called when the genes of an organism are changed? genetic modification (GM)
What 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
How would genetic modification in plants work? Crops could become resistant to some herbicides, which would then kill weeds without damaging the crop.
What is needed to carry the gene into the cell and what are used? The vector used is a plasmid.
What 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.
What is it called when a gene is active in a cell? It's expressed.
What is it called when fragments of DNA are grouped, so to speak? gel electrophoresis
What is used to multiply the amount of DNA found to make it usable? A PCR or polymerase chain reaction.
What 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.
How 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.
What 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.
Why 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.
What does it mean when our cells are specialized for a particular function? They're differentiated.
What area of the heart controls the muscle contractions? The pacemaker does.
What 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.
What 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.
What kind of object is an artificial heart valve? A product of biomedical engineering.
What do artificial pacemakers do? Monitor your heart beat and stimulate your heart to beat in a natural rhythm.
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