6.4 cloning and biotechnology Flashcards
define clone
genetically identical organism or cell produced by asexual reproduction and mitosis
advantages of natural cloning
if conditions for growth are good for the parent theyll be good for the offspring
cloning is rapid
reproduction can occur if only one parent available
disadvantages of natural cloning
offspring may become overcrowded
no genetic diversity (unless mutation)
little variation in population
selection is not possible
if the environmental conditions change the whole population is susceptible
define vegetative propagation
process of reproduction through vegetative parts of a plant to produce natural clones
name the different forms that a plant can reproduce to make natural clones
runners / stolons - horizontal stems that form from roots
rhizomes - horizontal stem but underground
suckers - new stems that grow from the roots of a plant
bulbs - over wintering mechanism, underground stem where new fleshy bases grow
corns - solid underground stem with scaly leaves and buds
leaves - clones grow on leaf margins (kalanchoe plant)
tubers - another type of underground stem (potato)
name a simple cloning technique
plant cuttings (between two nodes)
how to take plant cuttings
stem is cut between two leaf joints (nodes)
placed into moist soil
new roots will grow from the tissues in the stem
name ways of artificially producing clones in plants
tissue culture
micropropogation
define tissue culture
growing new tissues, organs or plants from a small sample of cells or tissue
why is tissue culture used
commercially to increase the number of new plants in micropropagation
define micropropagation
growing large numbers of new plants from meristem tissue taken from a sample plant
steps of micropropagation
plant material is selected and cut into small pieces (called explants)
explants are sterilised
placed onto a sterile growth medium containing suitable nutrients and plant growth hormones
stimulates cells to divide by mitosis to form a callus
callus is divided and the small clumps are stimulated to differentiate into different plant tissues
stimulates shoots to form which is then transferred to a greenhouse
advantages of artificial cloning
rapid method
carried out where sexual reproduction is not possible
displays same desirable characteristics
combination of characteristics retained as not lost through sexual reproduction
easier to grow and harvest
apical bud (meristem) used so free from virus
disadvantages of artificial cloning
tissue culture is labour extensive
expensive to set up facilities to perform it successfully
can fail due to microbial contamination
all cloned offspring are genetically identical
what type of cells are used in artificial cloning in animals
totipotent cells from embryos
name the techniques used for artificial cloning in animals
embryo twinning
somatic cell nuclear transfer
explain how embryo splitting works
a zygote (fertilised egg) is produced by IVF
divides by mitosis into a small ball of cells
cells are separated and allowed to continue dividing
placed into a surrogate mother
what is somatic cell nuclear transfer works
the cloning of an adult
explain how somatic cell nuclear transfer occurs
an egg cell is obtained and the nucleus is removed (enucleation)
normal body cell from the adult being cloned is enucleated
the nucleus is fused with the egg cell by applying an electric shock
the shock triggers the egg cell to start developing
the cell undergoes mitosis to produce a small ball of cells
young embryo is placed into the uterus of a surrogate mother
define non reproductive cloning
production of cloned cells and tissues for purposes other then reproduction
uses of artificical cloning
therapeutic cloning - new tissues and organs can be grown
scientific research - into action of genes that control differentiation
arguments for artificial cloning in animals
can produce a whole herd of animals with a high yield
produces genetically identical copies that retain characteristics
useful for scientific research as genotypes are the same
testing medicinal drugs on animals
can medically repair damaged tissues
increases numbers of endangered animals
arguments against artificial cloning in animals
lack of genetic variation = exposed to diseases
success rate is poor
expensive
ethical issues with regards to embryo use
advantages of using microorganisms in biotechnology
cheap and easy to grow
production takes place at lower temps = saves costs and fuels
can take place at normal atmospheric pressure
production is not dependant on the climate
microorganisms can be fed by products from other food industries
have a short life cycle and can reproduce quickly
can be easily genetically modified
fewer ethical considerations
product easy to harvest
define biotechnology
the use of living organisms in industrial processes
examples of what microorganisms can be used to make in biotechnological processes
yoghurt
cheese
baking bread
alcoholic beverages
proteins
advantages of using microorganisms in food production (protein)
production of protein is quicker then in plants/animals
biomass produced has a higher protein content
production can be increased due to demand
no animal welfare issues
no animal fat or cholesterol
disadvantages of using microorganisms in food production
eating fungal protein or food is unpopular
protein needs to be isolated - uses larger fermenters
protein needs to be purified
may contain different amino acids to normal
may become infected
doesnt taste of traditional protein sources
what are fermenters used for
commercial drug production uses large stainless steel containers to control growing conditions and ensure the best yield of product
what conditions are controlled in a fermenter
temperature
nutrient availability
oxygen availability
pH
product concentration
explain the difference between batch and continuous culture
continuous - product is produced and removed regularly as the broth is continually topped up with nutrients etc.
batch - culture set up with a limited amount of nutrients and is left to ferment and after the fermenter is emptied and product is extracted
explain the importance of asepsis in fermenters
sterile conditions maintained
as unwanted microorganisms would compete with the cultured microorganisms for nutrients and space
reduces the yield of the useful products
and spoil them
produce toxic chemicals and potentially destroy the cultured microorganism
name the different types of growth mediums
broth
agar
define aseptic techniques
sterile techniques used in culturing and manipulating microorganisms
procedure of aseptic techniques
wash hands
disinfect work area
use a bunsen burner to create convection to prevent air bourne microorganisms, create area of sterile air
pass neck of open bottles through the flame and as its closed
don’t lift the lid of the petri dish completely
pass equipment through flame
name the steps involved in growing microorganisms on agar plates
sterilisation
inoculation
incubation
explain the process of sterilisation
autoclave used to sterilise agar medium and equipment and use heat from bunsen burner flame during
explain the process of inoculation
the way of introducing microorganisms to a sterile medium
streaking - wire inoculating loop to transfer liquid
seeding - sterile pipette
spreading - a glass spreader used to spread out the microorganism
explain the process of incubation
petri dish labelled and taped lightly
placed in an incubator upside down
explain how serial dilutions can be used with liquid broth
serial dilutions reduce the population density of microorganisms by diluting the solution by a factor of ten in a liquid broth to make them easier to count colonies
define serial dilution
a sequence of dilutions to reduce the concentration of a solution or suspension
define closed culture
a culture which has no exchange of nutrients or gases with the external environment
explain the shape of the growth curve
lag phase - flat at the beginning
exponential phase/ log phase - line begins to curve/ gets steeper
stationary phase - line plateaus again
death/ decline phase - line declines
explain each phase of the growth phase
lag = early population growth is slow as the micro. are adjusting to the new environment
log = micro. have adjusted to the environment, population grows rapidly
stationary = rate of pop. growth begins to equal death rate
decline = nutrients run out, waste products may become lethal. pop. declines
explain the difference between primary and secondary metabolites
p = produced during normal activities, collected from a fermenter during the log phase
s = produced in the secondary phase, collected at the end or during decline
define immobilised enzymes
an enzyme that is held in place and not free to diffuse through the solution
advantages of using immobilised enzymes
extraction costs are lower as they don’t mix with the product
enzymes can be reused
continuous production is easier
enzymes are surrounded by a matrix so they are protected from extreme environments
explain the 3 ways of immobilising enzymes
adsorption - bound to a supporting surface by hydrophobic and ionic links
covalent bonding - bonded to a supporting surface using strong covalent bonds
entrapment - trapped in a matrix and the substrate and product diffuses in and out
name industrial uses of immobilised enzymes
glucose isomerase - converting glucose to fructose
lactase - converting lactose to glucose and galactase for lactose free milk
formation of semi synthetic penicillins
