Cloning and Biotechnology Flashcards
what is cloning
- process of producing genetically identical cells or organisms from cells of existing organisms
- natural / artificial
what is vegetative propagation
- production of plant clones from non-reproductive tissue
what are the natural vegetative propagation methods
Rhizomes (Bamboo)
- stem structures that grow horizontally underground away from a parent plant
- nodes where shoots and roots develop
Stolons/Runners (Strawberries)
- grow above the ground on the surface of the soil
- development of new shoots and roots
Suckers (Elm Trees)
- shoots that grow from sucker buds present on shallow roots of a parent plant
Tubers (Potatoes)
- underground structures that act as a food store
Bulbs (Onions)
- underground food stores
- new bulbs develop from original bulbs
how can plants be artificially cloned
- cells taken from original plant that is going to be cloned
- cells from stem and root tips are used as they are stem cells
- cells are sterilised to kill microorganisms
- cells placed on a culture medium containing plant nutrients and hormones
- cell divide and grow into small plant
- out of culture medium and planted in soil - develop into plants that are genetically identical to original plant
what are the arguments for - artificial plant cloning
- desirable genetic characteristics are always passed onto clones
- tissue culture allows plants to be reproduced in any season
- less space is required by tissue culture
- produces lots of plants quickly
what are the arguments against- artificial plant cloning
- undesriable genetic characteristics are always passed on
- cloned plants have no genetic variability - one disease can kill
- production costs of tissue culture is high - high energy - skilled professionals
- contamination
what is natural animal cloning
- sexual reproduction
- egg fertilised - can split in early stages and develop into multiple embryos with the same genetic information
- identical twins
what are the two ways of artificially cloning animals
- artificial embryo twinning
- somatic cell nuclear transfer
what is artificial embryo twinning
- egg cell is extracted from a female cow and fertilised in a petri dish
- fertilised egg divides at least once to form an embryo in vitro
- individual cells from embryo are separated into petri dishes
- each cell divides and develops normally - embryo forms in each petri dish
- embryos are implanted into female cows
- embryos develop inside and are then born
what is somatic cell nuclear transfer
- somatic (diploid)cell is taken from Sheep A
- nucleus is extracted and kept
- oocyte (immature egg cell)is taken from Sheep B and nucleus is removed to form an enucleated oocyte
- nucleus from A is inserted into enucleated oocyte
- B contains genetic information from A
- fuse together and stimulated to divide to produce an embryo
- embryo is planted into a surrogate mother
- lamb is born that is a clone of sheep A
what are the uses of animal cloning
Research Purposes
- test drugs
- variables that come from genetic differences are removed
- save endangered animals from extinction
- agriculture - increase yield of animals
- genetically modified to produce useful substances
- can produce just embryonic stem cells
what are the benefits of animal cloning
- desirable genetic characteristics are always passed on to clones
- infertile animals can be reproduced
- increase population of endangered species
- develop new treatments for disease
what are the negatives of animal cloning
- difficult, time consuming, expensive
- no genetic variability
- clones may not live as long as natural offspring
- using cloned human embryos as a source of stem cells - ethical issues - destroying a human life
what is reproductive cloning
- production of a whole genetically identical animal
- fusion of body cell with enucleated egg
- test new drugs
- save endangered animals
- increase number of organisms with desired characteristics
what is non-reproductive cloning
- production of genetically identical cells that don’t reproduce a whole organism
- embryonic stem cells
- potential to become any cell
what is biotechnology
- industrial use of living organisms to produce food, drugs etc
- microorganisms used
- uses enzymes
why should we use biotechnology
- ideal growth conditions created
- grow rapidly = fast products made
- grown on inexpensive waste materials
- grown at any time of the year
brewing
- to make beer yeast is added to a grain
- yeast respires anaerobically using glucose from grain and produces ethanol and CO2
Baking
- yeast makes bread rise
- CO2 produced by fermentation of sugars in the dough makes it rise
- flat breads are made without yeast
Cheese making
- made from rennet
- rennet contains chymosin which clots milk
- chymosin obtained from genetically modified yeast
- lactic acid bacteria convert lactose to lactic acid turning it sour and solidifies
- production of blue cheese = adding fungi
Yoghurt production
- involves lactic acid bacteria to clot milk
- creates a basic yoghurt
Penicillin Production
- fungi from Penicillium produces penicillin to stop bacteria growing
- fungus is grown under stress in industrial fermentations
- penicillin produced is collected and purified
Bioremeditation
- removal of pollutants from contaminated sites
- pollutant-removing bacteria has nutrients added to allow it to multiply and thrive
- bacteria breaks down pollutants into less harmful products
what are the benefits of using microorganisms in food production
- make single-cell protein - healthier alternative to animal protein
- grown quickly, easily
- simple growth requirements - grown on waste products, less land needed
- can be cultured anywhere
what is batch fermentation
- microorganisms are grown in individual batches in a fermentation vessel
what are the negatives of using microorganisms in food production
- as conditions can be used for all microorganism there is a risk of contamination
- may not like the idea of eating food grown on waste products
- single-cell protein doesn’t have the same texture of flavour as real meat
what is continuous fermentation
- microorganisms are continually grown in a fermentation vessel without stopping
- nutrients are put in and waste products taken out at a constant rate
how are the conditions inside fermentation vessels regulated and maximises yield
pH
- constantly monitored by a pH probe
- enzymes can work efficiently
temperature
- kept constant by a water jacket that surrounds the vessel
- enzymes work efficiently
Access to nutrients
- paddles constantly circulate fresh nutrient medium around the vessel
- ensure constant nutrient access
Volume of oxygen
- sterile air is pumped into the vessel when needed
- always have oxygen for respiration
Vessel kept sterile
- superheated steam after each use
- kills unwanted organisms
what is a closed culture
- growth takes place in a vessel that is isolated from the external environment
- extra nutrients aren’t added and waste products not removed
what are the features of a standard growth curve
Lag phase
- population size increases slowly
- microorganisms have to make enzymes
- low reproduction rate
Exponential Phase
- population size increases quickly
- culture conditions at most favourable
- no. microorganisms double at each interval
Stationary phase
- population size stays level
- death rate = reproduction rate
- microorganisms die as there isn’t enough food and poisonous waste builds up
decline phase
- population size falls
- death rate is larger than reproductive rate
- food is scarce and waste is toxic
what are isolated enzymes
- mixed in with products of a reaction
- products have to be separated from mixture using immobilised enzymes
- enzymes attached to insoluble material so they cannot become mixed with products
- substrate solution is run through a column of immobilised enzymes
what are the three ways enzymes are immobilised
- encapsulated in jelly like alginate beads, which act as a semi-permeable membrane
- trapped in a silica matrix gel
- covalently bonded to cellulose or collagen fibres
what are the advantages of immobilised enzymes
- columns can be washed and reused - reduces cost of running a reaction
- product isn’t mixed with enzymes
- more stable than free enzymes
what are the benefits of immobilised enzymes
- extra equipment = expensive
- more expensive to buy than free enzymes
- lead to a reduction in the enzyme activity as they cannot freely mix with substrate
conversion of lactose to glucose and galactose - use of immobilised enzymes
- some cannot digest lactose as they don’t produce lactase
- fresh milk can be passed over immobilise lactase to produce lactose-free milk
production of semi-synthetic penicillin - - use of immobilised enzymes
- some bacteria are penicillin resistant
- semi-synthetic penicillin produced and are effective against penicillin resistant bacteria
conversion of dextrin’s to glucose - use of immobilised enzymes
- glucose derived from starchy foods
- starch breaks down into dextrins which are broken down into glucose by immobilised enzyme glucoamylase
