Cloning And Biotechnology Flashcards
What are natural clones?
Clones are genetically identical copies which are produced by asexual reproduction in which the nucleus is divided by mitosis
What are some advantages of natural cloning?
- rapid
- only one parent required
- optimum conditions for parent will be the same for offspring
What are some disadvantages of natural cloning?
- offspring may become overcrowding
- no genetic diversity
- if environment changes the whole pop is susceptible
What is vegetative propagation?
Process of reproduction through vegetative parts of the plant rather than specialised reproductive structures
What are runners or stolens?
Stems which grow on the surface of the group
What are rhizomes by
Stems which grow underground
What are suckers?
New stems which grow from the roots of a plant, the original horizontal branch may die
What are bulbs?
Eg. Onions
- Underground stem from which grow fleshy leaves
- contain multiple apical buds that grow into new plants
What are corms?
- Underground stem with scaly leaves and buds
- more solid than bulbs
- remain underground over winter
What are tubers?
- Eg. Potatoes
- Another type of underground stem
- one potato grows into one or more plants
Example of cloning in animals?
When a zygote divides as normal but the daughter cells split to become two separate cells
How are cuttings made?
- stem is cut between two leaf joints (nodes)
- root cuttings, buried just below surface
- scion cuttings, dormant woody twigs
- leaf cuttings
What is tissue culture?
- A series of techniques used to grow cells, tissues or organs from a small sample of cells or tissue
- carried out on a nutrient medium under sterile conditions
- application of plant growth substances at correct times can encourage cells to differentiate
What are the steps to micropropagation?
- Suitable plant material is selected and cut into small pieces called explant (meristem tissue often used)
- Explant sterilised using bleach or alcohol to kill any fungi or bacteria
- Explants placed on a sterile growth medium (often agar) containing suitable nutrients eg. Glucose as well as auxin cytokinin stimulates the cells of explants to divide into a callus/mass of totipotent cells
- Once a callus has formed it divides to produce a larger number of clumps of undifferentiated cells
- Clumps are moved to different media with different ratios of auxin and cytokinin stimulating different areas to grow
- Once tiny plantlets are formed they are transferred to a greenhouse with optimum growth conditions
What are some advantages of artificial cloning in plants?
- rapid
- Only one parent necessary
- desirable characteristics can be maintained
- using apical bud (meristem) ensures the new plants are free from viruses
What are some disadvantages of artificial cloning?
- tissue culture is labour intensive
- tissue culture is expensive
- genetically identical clones means all susceptible to the same pests/diseases
- tissue culture can fail due to microbial contamination
What are totipotent cells?
Undifferentiated cells
Explain the steps to embryo splitting
- A zygote (fertilised egg) is created by in vitro fertilisation(IVF)
- Zygote allowed to divide by mitosis into a small ball of cells
- Cells are separated and allowed to continue dividing
- Each small mass of cells is placed into the uterus of the surrogate mother
What does embryo splitting lead to?
- Precise phenotype will be unknown until animals are born
- dependant on the sperm and egg used
Explain the process of somatic cell nuclear transfer
- Egg cell is obtained and is enucleated
- Somatic (normal body) from the adult to be cloned is removed and may have the nucleus removed
- Complete somatic cell or simply it’s nucleus is fused with the empty egg cell via an electric shock, which also triggers it to start developing
- Cell undergoes mitosis to produce a small ball of cells
- Young embryo is placed into the uterus of a surrogate mother
What is therapeutic cloning?
A process of non-reproductive cloning
- skin is grown in vitro as a graft over burnt areas
- been used to restore capability of producing insulin in the pancreas in a mouse
- potential to grow whole new organs
What is an advantage of therapeutic cloning?
The tissues used are grown from the patients own cells, so this avoids rejection
What are some arguments for artificial cloning in animals?
- testing on cloned tissues avoids animal testing
- herd of animals with high yield can be produces
- endangered species can be cloned
What are some arguments against artificial cloning in animals?
- lack of genetic variation, herd exposed to diseases or pests
- low success rate
- ethical issues regarding how long embryo survives if developed for research purposes
What are some examples of how biotechnology is used to make food?
- ethanol in beer and wine: yeast
- co2 used to make bread rise: yeast
- lactic acid used to make cheese & yoghurt: lactobacillus bacteria
- mycoprotein- fungus protein used to make vegetarian food: fusarium Venenatum fungus
- soya beans fermented to produce soy sauce: yeast
What are some examples of how biotechnology is used to make pharmaceutical drugs?
- penicillin / other antibiotics: fungus
- insulin / other human proteins
What are some examples of how biotechnology is used to make enzymes?
- protease and lipase used in washing powders
- sucrase used to make food sweeter
What are some advantages of using microorganisms in biotechnology?
- relatively cheap and easy to grow
- production process takes place at lower temp than chemical engineering, reduces fuel costs
- reproduce quickly
What is biotechnology?
Technological processes that make use of living organisms to manufacture useful products or services
How can you use larger organisms in biotechnology?
Genetically-modified animals that possess a particular gene can be bred
Eg. Proteins incorporated into milk
Explain the production of yoghurt
- A milk that has undergone fermentation by diff types of bacteria
- Bacteria convert lactose to lactic acid causing the milk to coagulate
- probiotics which strengthen the immune system may be added
Explain the production of cheese
- Milk treated with bacteria that convert lactose to lactic acid
- It is then treated with rennet which contains the enzyme rennin
- Rennin causes the milk protein casein to coagulate in the presence of calcium ions:
1. Kappa-casein is broken down
2. Casein is precipitated by the action of calcium ions which bind the molecules together Resulting in a curd
Explain the process of baking
- Bread is a mixture of flour water and yeast producing dough
- proving/fermenting, dough is left to warm while yeast aerobically respires producing co2 bubbles
- cooking, risen dough is baked. Alcohol evaporates
Explain how alcoholic beverages are made
Product of anaerobic respiration of yeast:
- grape skin contains yeast and grape contains glucose and fructose which together produces CO2 and alcohol
- beer is brewed using barely grains through malting which begin to germinate converting starch to maltose which is respired by yeast producing CO2 and alcohol
what are some advantages of using microorganisms for the production of food?
-Biomass produced has high protein content
-no animal welfare issues
Production of protein is much faster than that of animal protein
what are some disadvantages of using microorganisms for the production of food?
- people may not want to eat fungal food grown on waste
- protein must be purified to ensure it’s not contaminated
What conditions must be controlled within a fermenter?
- oxygen availability- for aerobically respiring microorganisms
- pH, can effect enzymes
- temp, can effect enzymes
- conc of product
- nutrients available
How is a fermented set up?
It must first be sterilised using a superheated system. It can then be filled with the components for growth with a starter culture of the microorganisms. It should then be left to synthesise the products
What are primary metabolites?
- Products synthesised by the microorganism during normal metabolism when they are actively growing
- They can be extracted continuously from the broth often during the log phase
What are secondary metabolites?
- products produced only when the cells are placed under stress such as high pop density or limited nutrient availability
- culture is set up w/ limited nutrients for a specific amount of time
- the fermenter is emptied and product can be extracted- known as the batch culture (at the stationary phase)
What are aseptic techniques?
- Wash your hands
- Disinfect work space
- Have a Bunsen burner operating nearby to kill airborne microorganisms settling
- As you open a bottle pass it over the flame to prevent airborne microorganisms entering
- Do not entirely lift lid of petit fish just enough to introduce necessary bacteria
- Any glassware should be passed through the flame before and after contact with desired microorganisms
What is sterilisation?
- Medium is sterilised by heating in an autoclave which kills all living organisms
- Medium is poured into sterile Petri dishes after being cooled
- lid of Petri dish should be kept on to prevent infection
What is inoculation?
Introduction of microorganisms to a sterile medium:
- streaking - wire inoculating loop transfers medium
- seeding - small drops of medium
- spreading - glass spreader used to spread drop
What is incubation?
- Petri dish must be labelled
- lid should be taped to the bottom but not entirely sealed to avoid growth of anaerobic bacteria
- should be kept upside down to prevent condensation falling
- examine after 24-36 hours
- Petri dish should not be opened
How will bacteria growth appear in a liquid medium?
Initially clear but will turn out cloudy when bacteria have grown
What are serial dilutions?
- Step-wise dilution of broth culture. At each step the broth is diluted by a factor of 10. Take a 1cm sample of broth add 9cm of water label as 10^-1 etc.
- Each successive dilution can be used to inoculate an agar plate one will produce a culture plate where the numbers can be counted
What is the lag phase in a growth curve?
Early part of pop growth where it does not grow quick due to population being small and organisms adjusting to their environment
What is the log (exponential) phase in the growth curve?
- organisms have adjusted to environment as they have the enzymes needed to survive
- each individual has sufficient nutrients to grow rapidly so pop doubles in size with each generation
What is the stationary phase?
- increasing numbers of organisms use up nutrients so produce increasing amounts of waste products such as carbon dioxide and other metabolites
- rate of population growth declines to a rate where it is in equilibrium with death rate
What is the death (decline) phase?
- Nutrients run out and conc of waste products may become lethal
- more individuals die than are being produced so population begins to fall
What are immobilised enzymes? And what are some advantages of this?
Enzymes do not mix freely with the substrate:
- reduced extraction costs
- enzymes can be reused
- enzymes protected by immobilising matrix which protects them from extreme conditions
What is adsorption? Limitations?
- Enzyme molecules are bound to supporting surface eg. Clay or glass by hydrophobic interactions and ionic links
- some of these links may alter the active site of the enzyme affecting enzyme activity
- bonding forces aren’t always strong enzymes can become detached
What is covalent bonding as a technique for immobilising enzymes? Limitations?
- Bonded to supporting surfaces eg. Clay by covalent bonds using a cross link agent which may also link them in a chain
- can be expensive
- can distort active site
What is entrapment?
- enzymes trapped in a matrix that do not allow free movement but does not alter the shape of the enzymes
- substrate molecules must be able to diffuse in and products out
What is membrane seperation as a technique for immobilising enzymes?
- Enzyme molecules separated from reaction mixture by a partially permeable membrane
- Enzymes must be small enough to pass through the membrane via diffusion
- could limit reaction rate
What is glucose isomerase?
- Converts glucose to fructose
- used to produce high fructose corn syrup
What is penicillin acylase?
- Semi-synthetic penicillin such as amoxicillin
- some penicillin resistant bacteria are not resistant to these
What is lactase?
- Converts lactose to glucose and galactose by hydrolysis
- people who are lactose intolerant need calcium supplements
