cloning and biotechnology Flashcards
what is vegetative propagation
natural cloning of a plant so that it is genetically identical to the parent. can take place from the stem, leaf, bud, root of the parent
what are penernnating organs and why are they important
enable plant to survive adverse conditions
contain stored food for PHS and can remain dormant in the soil. enable asexual reproduction
ie bulbs, runners, rhizomes and stem tubers
how do farmers carry out vegetative propagation
take cuttings, plant them, use rooting hormones to encourage growth of new roots
give advantages of vegetative propagation
faster, guaranteed quality of the plant
lacks genetic variation so more susceptible to environmental changes such as disease.
give advantages and disadvantages of vegetative propagation
faster, guaranteed quality of the plant
lacks genetic variation so more susceptible to environmental changes such as disease.
what is the name given to artificial cloning of plants and when is it used.
micropropagation or tissue culture
typically used when a plant does not produce seeds, is very rater, required to be pathogen free
explain how micropropagation is carried out
- a small sample of tissue is taken, meristem tissue is dissected in sterile conditions. the material removed from the plant is called the explant
- the sample is sterilised using ethanol or bleach
- the explant is put in a sterile culture medium containing a balance of hormones (auxin, cytokines) which stimulate mitosis
- the cells proliferate forming a mass of cells known as a callus. the callus is divided up into individual cell clumps and transferred into a new culture medium containing a new range of hormones for development of genetically identical platelets
- the plantlets are the potted where the grow into small plants
for and against argument of micropropagation
+ rapid production of large numbers of plants
+ disease free plants
+ increases the population of seedless plants to meet demands ie grapes and bananas
+ can grow plants that are naturally infertile ie orchids
+ increases the number of rare or endangered species
- monoculture so susceptible to environmental changes
- expensive process and requires skilled workers
- large numbers of plants can be lost during the process
- if the parent is infected with a virus then all of the clones will be too.]
give examples of cloning in animals
monozygotic twins
amphibians and reptiles can produce offspring when no male is available
star fish can regenerate themselves
flatworms can form new identical animals as part of their reproductive cycle.
how are animals artificially cloned
artificial twinning and somatic cell nuclear transfer
outline the stages of SCNT
- Nucleus is removed from the somatic cell of an adult animal
- nucleus is removed from a female gamate of the same species
- electrofusion is used to fuse the nucleus from somatic cell donor and the enucleated cell from female donor
- embryo is grown in vitro
- early embryo is split
- the embryo is then transferred into the uterus of a third animal.
the off spring is a clone of the somatic cell donor
what are problems with SCNT
can lead to premature ageing so reduces life span
what is pharming
the production of animals which have been genetically engineered. SCNT has been used in farming to produce therapeutic human proteins in milk
what is pharming
the production of therapeutic human proteins. SCNT has been used in farming to produce therapeutic human proteins in milk
outline the process of artificial twinning
- select an animal with desirable traits, treat with hormones so she super ovulated releasing more eggs which can be fertilised naturally or in the lab.
- early embryos are flushed out of the uterus. these cells are totipotent ( have the ability to form an entire new species) and are split to produce several smaller embryos each capable of growing into a full term calf.
- they are grown in a lab for a few days and then implanted into a surrogate mother to be born naturally.
outline the process of artificial twinning
- select an animal with desirable traits, treat with hormones so she super ovulated releasing more eggs which can be fertilised naturally or in the lab.
- early embryos are flushed out of the uterus. these cells are totipotent ( have the ability to form an entire new species) and are split to produce several smaller embryos each capable of growing into a full term calf.
- they are grown in a lab for a few days and then implanted into a surrogate mother to be born naturally.
what are pros and cons of animal cloning
pros
rare species
top race horses or pets
pharming and milk proteins
cons
inefficient most animals take lots of clones to have success
produces malformed offspring
likely to miscarry
shorten life span
could be taken too far
ethics
people don’t want ti eat food that has been cloned
what are the four stages of growth in a fermenter in order
lag phase
log phase/exponential phase
stationary phase
death phase
what are primary metabolites, give some examples and what phase are they produced
essential metabolites needed for survival, growth, development and reproduction ie glucose, sucrose, carbon dioxide, ethanol
lag phase
what are secondary metabolites and what phase are they produced
non-essential
pigments, antibodies, toxins
stationary phase
what 3 factors can limit the rate of yeast growth in a fermenter
sugar availability
pH falls too low (enzymes denature)
high ethanol concentration (inhibits)
why would glucose be used as a respiratory substrate before maltose
maltose must be hydrolysed into two molecules of glucose. this requires an enzyme called maltase which is only available when in glucose is in low concentrations
give some advantages of using yeast in fermentation
low temperatures - less expensive to maintain
uses waste material such as sugar cane waste as a substrate
does not use up non renewable resources such as fossil fuels thus more sustainable
products are carbon neutral (better for the environment)
give some disadvantages of using yeast in fermentation
requires sterile conditions to ensure no contamination
is inhibited by product
need separating/purifying
time consuming
what are immobilised enzymes
enzymes attached to an inert, insoluble material
what are immobilised enzymes
enzymes attached to an inert, insoluble material
describe how you would made alginate beads and how they can be used to make lactose free milk
- mix enzymes with sodium alginate.
- add drop by drop into calcium chloride.
insoluble complex forms (alginate beads). - the alginate beads are put in a column
- run substrates through the column (milk)
- collect the products at the bottom (fructose for corn syrup, lactose free milk)
how can you increase the percentage yield of lactose free milk?
run the test more then once through the column
incubate for longer by reducing the flow rate
test for the named sugars in milk (glucose using Benedicts solution)
why do we use immobilised enzymes
- can be reused
- enzymes can be easily recovered
- longer shelf life of enzymes
- less downstream purification is needed as the product is kept enzyme free so does not effect product quality
- more product per unit of time
- more tolerant of pH changes
- thermostable less likely to denature at high temperate
why are immobilised enzymes more tolerable of pH and high temp
pH
alginate protects enzymes as it is less exposed to the solution.
less H+ and OH- penetrate the alginate beads so the shape is less disrupted
At high temperatures
H bonds vibrate less at higher temps
fewer bonds within immobilised enzyme break
active site is less likely to change shape
less denaturation
has a wider range of optimum
what are the five different methods of making immobilised enzymes
adsorption
hydrophobic/ionic bonds to a solid material ie carbon, clay, resin, glass
covalent bonding/cross linking to a names substance ie collagen, cellulose
membrane seperation (microcapsules)
encapsulation ** (suspend in a matrix - collagen, silica, cellulose)
Suggest two ways in which named factors inside the fermenter could be adjusted in order to maximise the yield
- increase nutrients ie glucose and stir so there is a continuous supply
- increase aerobic respiration by increasing supply of oxygen
- maintain temp and pH at optimum
- remove waste products to reduce pressure
- prevent entry of other harmful microbes
what are xenotransplates. give an example
a tissue graft or organ transplant from a donor of a different species from the recipient. ie replacement hearts from transgenic pigs, partially tissue-matched to humans
what is Recombinant DNA
DNA from two different sources
give examples of some vectors that can be used in humans and animals
viruses, liposomes
give some vectors that can be used in plants
ti plasmids, Agrobacterium tumefaciens, liposomes
give examples of some vectors that can be used for prokaryotes
bacteriophages, BAC, plasmids
what is biotechnology
large scale, industrial use of living organisms (such as yeast, lactosebacillius) to produce beer, bread, cheese, yoghurt as well as drugs such as penicillin and insulin
what are advantages and disadvantages of using microorganisms for commercial use
+ they are fast reproducing
+ cheap
+ work at low temperatures, safety and expense
+ products are easy to separate
+ can be genetically modified
+ no welfare issues
+ can reproduce all year round
- can produce toxins if conditions are not at optimum
- need sterile conditions
- people may have concerns about eating GM food
- require additives (little natural flavour)
- microorganisms have to be separated from nutrient broth
outline the brewing process
malting - barley is germinated. heated slowly to a high temperature. producing enzymes that hydrolyse starch into glucose and kill unwanted pathogens. malt is produced.
mashing - hops are added with sterile qualities and flavour
fermentation - added to yeast. temperature is maintained at optimum for anaerobic conditions. ethanol is produced. pH gets low and yeast is inhibited.
maturation - beer is conditioned for 4-29 days
finally the beer is filtered, pastured and bottled.
how is bread made
yeast is added to ingredients to make bread.
left in warm conditions to rise
dough is kneaded (air removed) and then left to rise again
cooked in a hot oven. the carbon dioxide bubble expand so that the bread rises. the yeast get killed
outline how is cheese made
milk is pastured (heated to kill bacteria) and homogenised (fat droplets are evenly distributed)
mixed with bacteria and chymosin enzyme until the milk separates into solid curds and liquid whey. rennin converts soluble casein protein to soluble paracasein
paracasein reacts with calcium ions to form insoluble calcium paracaseinate (curds).
curds are cut and cooked in whey and strained in draining cloths.
whey is used as animal feeds
curds are put into wooden drums to be pressed
the cheese is left to dry and mature for days -> years.
how is yoghurt made
milk is pasteurised and homogenised
then lactobacillus and streptococcus are added and incubated for 4-5 hours
why is it important to maintain sterile conditions during fermentation
- to ensure products are not contaminated so that the Bach is usable
- to reduce competition for nutrients
- so conditions (pH) remains unchanged
