6.2.1 - Cloning And Biotechnology Flashcards
Clones def
They are genetically identical to their one parent.
They are formed by asexual reproduction
How does asexual reproduction occur in eukaryotes and prokaryotes
Mitosis in eukaryotes
Binary fission in prokaryotes
List examples of natural clones in animals or plants
Animals:
Identical twins
Plants - via vegetative propagation
- corms
- leaves
- suckers
- bulbs
- Rhizomes
- runners
- Tubers
List advantages and disadvantages of clones in animals and plants
Explain why these are pros or cons
Pros:
- quick - increases production - increase chances of survival - increase chances of passing on genetic material, also have quicker evolution of organism to suit environment
- possible when sexual reproduction fails/isn’t possible - population is still maintained
- all offspring have genes to survive in their environment - increased chance of survival in environment - increase chance of passing on genes to future generations
Cons:
- overcrowding - increased competition for resources
- no genetic variation - more susceptible to disease
Vegetative propagation def
Production of structures in an organism that can grow into new organisms, genetically identical to the parent (clones).
How is vegetative propagation possible
Many parts of plant contain undifferentiated meristem tissues and cells
- these can differentiate into any cell type in the plant (totipotent)
Plant cuttings mechanism
- stem cut at a node
- remove bark if present to avoid the formation of a callus (a mass of undifferentiated cells)
- add rooting powder, depending on plant species (some will take root less easily)
- cut end of stem buried into soil
- new roots will begin to grow into the soil
(- what hormones can be added to aid growth) - process also possible from root cuttings, scion cuttings (in woody twigs) and leaf cuttings
- ref to aseptic conditions
What is a callus?
A growing mass of undifferentiated meristem cells or parenchyma cells that forms over the surface of a wound or cut of a plant
Runners, stolons, rhizomes, suckers growth infomation
- grow from horizontal stems that can form roots at certain points
- these are called runners or stolons if they grow on surface
- are rhizomes lf they are underground
- suckers are new stems that grow from root of plants
- in all cases, original horizontal branch may die
- leaves the new stem as a separate individual
Bulbs growth info
- consist of underground stem from which grow a series of fleshy leaf bases
- there is also an apical bud
- grows into a new plant in spring
- often bulb contains more than one apical bud, each of which grow into a new plant
Leaves growth info
- clones grow asexually
- clones/seeds grow on leaf margins
- immature plants drop off leaf and take root
Tubers growth info
- underground stem
- e.g. potatoes
- one potato grows into one or more plants
- each new plant can then produce many new tubers later that year (potatoes)
Micropropagation def
Growing large numbers of new plants from meristem tissue taken from a sample plant
Tissue culture def
Growing new tissues, organs or plants from certain tissues cut from a sample plant (explant)
Micropropagation mechanism
- Tissue from apical buds (an explant) taken because it is meristematic
- therefore undifferentiated and can still undergo mitosis
- Surface is cleaned using sterilising agent to
- ensures aseptic conditions so that no bacteria can grow as it could compete with the plant tissue
- Explant is placed onto nutrient medium to encourage mitosis
- this produces a callus (mass of undifferentiated cells)
- The callus is subdivided and placed in a new nutrient medium
- encourages differentiation of tissue. It contains:
> auxins - stimulate formation of root hairs
> cytokinins - stimulate shoot growth
> magnesium - helps the plant make chlorophyll > nitrates needed for protein synthesis
> sucrose - converted to glucose for respiration - The callus cells will grow into plantlets
- can then be then placed in sterile soil
- plantlets then grown in a greenhouse to acclimatise to normal growing conditions
Advantages of artificial cloning of plants
- genetically identical - maintains favourable charcateristics
- quicker to produce
- more likely to survive - due to callus (undifferentiated cells) being more subdivided
- more clones can be produced than using seeds
- disease free
- easily gentically maipulated
- can be used for cloning infertile plants
- easy to transport/store
Disdavantages of artificial clones of plants
- genetically idebtical - all susceptible to same diseases
- loss in gentic diversity
- farmers have to buy the plants from suppliers
- patented property
- high cost, expensive to do
- cant replicate them yourself
- labour intesive, people need to be trained
Micropropagation (tissue culture) is one method used for the artificial propagation of new plants.
Small amounts of tissue are obtained from plants and used to produce clones
Explain the importance of each of the above steps. (Not included).
(6 Marks)
Two methods of artificially cloning animals (reproductive cloning)
- embryo twinning
- somatic cell nuclear transfer
How embryo twinning occurs
- A zygote is created by IVF
- It is allowed to divide to form a small ball of cells
- These cells are separated and continue to divide separately
- Each of these cells is placed into a surrogate mother
Applications of embryo twinning
Cloning ‘elite’ farm animal (best characteristics) Scientific research (e.g. cloning fruit flies for testing/research)
How to stimulate mitosis in cells (not on spec)
- electrical shocks
- presence of certain chemical/hormones/signalling cells
Cloning animals by nuclear cell transfer mechanism
Egg cell enucleated (nucleus removed)
Adult somatic cell diploid nucleus from a different animal removed and injected into enucleated egg cell (or adult cell fused with enucleated egg cell)
Cell given a small electric shock to stimulate mitosis in egg cell
Cell grows into an embryo in vitro (outside body)
(Embryo can be split into several embryos - to produce artificial twins)
Embryo(s) implanted into surrogate mother
Why a clone is not entirely genetically identical to nucleus donor
DNA also found in mitochondria
Only get DNA from nucleus in clones
Mitochondrial DNA only found in cytoplasm
How to collect clones for IVF or cloning
Treated with hormone (FSH - follicle stimulating hormone)
Superovulation
Collect eggs from ovaries
How surrogates could be prepared for implantation of embryo
Hormone treatments
Prepare uterus by causing lining to thicken
So provide an increased blood supply to placenta
Non-reproductive clones def
Cloned cells and tissues used for other purposes (not reproduction)
Therapeutic cloning def
New tissues and organs can be grown and replaced in patients where damaged
E.g. skin grafts, pancreatic cells/beta cells producing insulin, spinal cord damage, etc.
Pros of artifical cloning of animals
Scientific research - response to treatment would be the same
Elite farm animal production - clone animals with most desirable characteristics
Produce desirable characteristics
Reduce possibilities of disease
Cons of artificial cloning of animals
Lack of genetic diversity
Ethical reasons, unnatural, etc.
Biotechnology def
The industrial use of living organisms to produce food, drugs or other products
4 main areas of biotechnology
Food
Drugs
Enzymes
Other products
Food production biotechnology examples
- bacteria used?
Baking - yeast Brewing - Cheese making - rennet Yoghurt Making - Penicillin production - Penicillium Insulin production - Bioremediation -
Enzyme production biotechnology examples
Showbie
Pharmaceutical drug production biotechnology examples
Showbie
Other products biotechnology examples
Showbie
Advantages of using microorganisms in biotechnology
Cheap and easy to grow
Easy to genetically modify them
High temp not required to produce them, saves fuel cost compared to other processes, e.g haber process
Normal atmospheric pressure can be used to produce, safer
Not dependent on climate - can be done anywhere
Products released - easy to harvest
Short life cycle - can reproduce very quickly
Purer products produced - no unwanted byproducts
Waste products from other processes can be re-used
Process of making cheese
Milk coagulation by bacteria
They convert lactose to lactic acid
Mixed with rennet
Rennin (enzyme) in rennet and Ca2+ coagulate (thicken) milk protein (casein)
Solid milk is called curd - pressed into cheese
Process of baking
Mix ingredients to make dough
In ‘proving’, yeast anaerobically respires
This produces CO2 and bread rises
Baking evaporates ethanol from anaerobic respiration
What conditions can fermenters control?
How do they control it
Optimum condition such as:
Pressure -
Temperature - cooling water in system
pH - pH and temp monitors - use buffer solution
O2 and CO2 conc. - sterile air added - O2 needed for aerobic respiration, anaerobic etc.
Nutrients added - carbon, nitrogen, vitamins and minerals needed for growth
Two types of fermentation
Batch and continuous
Info about batch fermentation
Microorganism starter population mixed with fixed quantity of nutrients at start ‐ no more added
At end products removed and tank emptied. Process started again.
Produces secondary metabolites after exponential phase (during stationary phase) because nutrients deplete
e.g. Penecillium making antibiotic Penicillin
Growth slower
Easy to set up and maintain
Contamination = loss of just one batch
Less efficient
Info about continuous fermentation
Nutrients and products added and removed from culture continuously
Produces primary metabolites during exponential phase because nutrients do not deplete and culture stays in exponential phase e.g. Insulin from E.coli
Growth faster
Quite difficult to set up and maintain
Contamination = loss of much product
More efficient
Explain how the student could modify the fermenter for continuous fermentation.
If you wish, you may add annotations to the figure to help you in your answer.
(4 Marks)
Different phases in standard growth phase for batch fermentation
What happens in each stage
Lag phase - bacteria start to grow
Log phase/Exponential phase - exponential growth
Stationary phase - growth stops
Death phase - bacteria die faster than they multiply
Metabolites def
Products of metabolic reactions
Features of primary metabolites
• Produced during normal (log) growth phase
• Essential for normal cell growth/reproduction
> match growth in population (i.e. same pattern as growth curve)
Sedondary metabolites features
• Not produced during normal (log) growth phase
• Produced after normal growth phase
• Not essential for normal cell growth/reproduction
> does not match the growth in population
> most antibiotics are secondary metabolites
Microorganism population growth equation
N = No x 2^n
N = number of cells in population No = number of cells in population at start n = number of generations that have occurred
Primary metabolite def
Molecule made in or needed for a cell’s normal survival or function
E.g. glucose, sucrose, named enzymes or amino acids, etc.
Aspesis def
Absence of unwanted microorganisms
Aseptic techniques def
Any measure to avoid contamination of sample or area from outside or foreign microorganisms
- important to get reliable and repeatable data
Importance of asepsis when manipulating microbes
Sterile def
- difference between sterile and asepsis
Sterile - absence of all microorganisms
- asepsis is absence of unwanted microorganisms, e.g. harmful, sterile is absence of all microorganisms
The nutrients required to grow microorganisms in a lab and processes needed for it
- respiration - any carbon compound
- protein synthesis - nitrogen containing compounds
Aseptic techniques - what can be done to reduce contamination
- wash hands
- disinfect surfaces
- heat the air so microorganisms don’t settle
- flame opening to any microorganism containing vessel before and after
- flame equipment
- limit air exposure, e.g. when petri dish lid is removed
Sterilisation mechanism
Both the growth medium and the equipment must be sterilised
The equipment is sterilised through heating
Medium is sterilised using an autoclave
It is heated to 121 Degrees C for 15 mins
It is then poured into a sterile Petri dish and left to set
These processes kill all living microorganisms
Explain the importance of maintaining aseptic conditions in manufacturing penicilin by fermentation.
(3 Marks)
to avoid unwanted microbe entry So no competition for nutrients So conditions in fermenter remain unchanged So no decrease in yield of penicillin - max profit for industry
So no contamination of batch/penicillin
- so batch is unusable
To prevent escape of Penicillin from the system
How is incubation carried out
Stored upside down (remove dripping condensation) Warm environment Examined after 24-36 hours after Do not open! Each colony is from a single bacteria Sterilised after use and before disposal
Inoculation mechanism (Aseptic techniques PAG)
Cap is removed from sterile broth and tube mouth is flamed
Unheated loop is inserted into tube of sterile broth
Loop is removed from broth and tube mouth is flamed
Tube enclosure is returned to tube
Loop is flamed and returned to receptacle
Immobilised enzyme def
Enzymes attached to an insoluble material in order to keep them separate from the reaction mixture
Immobilised enzyme info
Substrate molecules can still form ESCs
But once product is formed, it is released into mixture whilst enzyme remains separate (more cost effective)
4 methods to immobilise enzyme
Entrapment - trapped in alginate beads or cellulose mesh
Adsorption - stuck into collagen/clay/resin/porous glass
Covalent bonding to clay
Membrane separation - partially permeable membrane
Advantages of immobilised enzymes in large scale production
Product uncontaminated by enzyme therefore no downstream processing - less cost/expensive
Enzyme not lost during process and therefore reusable - Reduces cost
Matrix protects the enzyme so enzyme works at higher temperatures so reaction can be faster done at higher temps
Matrix protects the enzyme so enzyme works in changed pH
Suitable for continuous culture (long shelf life)
Disadvantages of immobilised enzymes in large scale production
Immobilisation difficult/expensive
Can be less active as substrate has to get through beads etc, so don’t form ESCs as readily
Function of glucose isomerase
Converts glucose to fructose to make high fructose corn syrup (sweeter than sucrose).
Function of penicillin acylase
Creates semi-synthetic penicillins.
- useful for people that are allergic to natural penicillin
Function of lactase
Converts lactose to glucose and galactose by hydrolysis to make lactose-free milk.
Function of aminoacylase
A hydrolase enzyme used to produce pure samples on L-amino acids by removing acyl group from the nitrogen of an N-acyl-amino acid.
Function of glucoamylase
During the hydrolysis of starch short polymers of glucose are made (dextrins) which can then be further hydrolysed to make glucose.
Nitrile hydratase function
Converts nitriles to amides (some of which can be used to make plastics).
State one advantage and a disadvantage of using clones to test treatment for a disease.
(2 Marks)
Pros:
- genetically identical - all react the same
- genetic variable controlled
Cons:
- expensive to produce clones
- don’t see varied responses to drug like in real populations (e.g mice)
- clones may have unknown health issues
- this could affect their response to treatment
Adult cell cloning can be used to investigate the development and treatment of disease.
Outline two other potential applications of adult cell cloning
(2 Marks)
- to produce elite/best animals - desirable characteristics
- to save/preserve endangered animals/recreate extinct animals
- grow/produce spare stem cells/tissues/organs
- AVP - e.g. cloning GM animals, etc.
Describe the differences between:
somatic cell gene therapy and germ line cell gene therapy
(2 Marks)
Somatic:
- changes/uses body cells
- changes cannot be passed to offspring
- cures genetic diseases in one individual
- short-lived - repeat treatments needed
Germ line:
- changes/uses gametes
- germ line change could be passed to offspring
Glucoamylase enzyme function
Conversion of dextrins to glucose
Advantages and disadvantages of using microorganisms to make food for human consumption
Need to write
Arguments for and against artificial cloning in animals
For:
- maximise agricultural output/yield e.g. produce more milk
- remove less desirable characteristics from gene pool
- help preserve endangered species
- provide regenerated organs for patients suffering from degenerative diseases
- will be a direct match - so no chance of rejection by immune system
Against:
- ethical reasons, e.g. embryos destroyed
- unknown long term effect sir cloning process
- process of somatic cell nuclear transfer doesn’t always work
- potential health problems that clones can have, e.g. breathing/circulatory problems
Spec - the importance of manipulating the growing conditions in batch and continuous fermentation in order to maximise the yield of product required
Need to write
Spec - why are microorganisms used in biotechnology
- short life cycle
- cheap to use and produce
- quick and easy to produce
- growth requirements - very few nutrients needed - cheap and easy, etc.
Uses of reproductive cloning of animals
Conservation of endangered species/extinct species
Lab animals - same response to given treatments
Therapeutic cloning def
Cells or organs are grown in tissue culture to repair/replace damaged tissues
Why does embryo splitting occur at the 8 cell phase
Because up to that point cells are totipotent
- so after that cells begin to specialise
Two advantages to a farmer of using embryos produced by embryo twinning.
(2 Marks)
- desirable characteristic - highest milk yield etc.
- rare breeds conserved
- sex/gender controlled
Explain why plants produced from micropropagation form clones.
(2 Marks)
Mitosis - asexual reproduction
- genetically identical
- tissue taken from cambium in stem is meristem
- meristem are totipotent - can differentiate into any cell type and so can grow into any tissue to produce new plants
Give one advantage of runners
Plant can reproduce even if it is one isolated individual
No reliance on pollination
Reproduction is faster
Why is asexual reproduction faster than sexual reproduction
Does not require development of sex organs or specialised haploid gametes
Organism does not need to release male gametes, nor do they need to be released by another individual
Time taken to find a mate to sexually reproduce with
