6.2.1 Cloning and bio technology Flashcards
What is vegetative propagation?
- Production of plant clones from non-reproductive tissue (roots, leaves, stems etc)
How do you produce clones from cuttings? (steps)
- Take a cutting of a stem of the plant with a sharp scalpel
- Remove lower leaves
- Dip the lower end in rooting powder which contain growth hormones
- Place the cutting in a suitable growth medium
- Keep the cutting in a warm and moist environment
- When the cutting has formed enough roots it can be planted elsewhere
What are some natural clones in plants?
- Rhizomes (Bamboo)
- Bulbs (Onions)
- Tubers (Potatoes)
- Runners (stolons) (strawberries)
How to perform tissue culture?
- Undifferentiated stem cells are taken from the meristem or root tips
- These cells are sterilised to kill any microorganisms
- The cells are placed in a growth medium containing nutrients and growth hormones
- The cells divide to produce a mass of undifferentiated cells called a callus
- When the cells have divided and grown into a small plant it can be planted
How can plants be cloned in HORTICULTURE? (3 ways)
- Cuttings
- Grafting
- Layering
Where can you take cutting from in a plant?
- Stem
- Root
- Leaf-cutting
What is micropropagation?
- Cells are taken from a developing cloned plant and are subcultured
- You can grow a lot more clones at once
Arguments for artificial cloning
+ Desirable genetic characteristics in plants (Brambley apple pies)
+ The plant is Rare
+ The plant does not readily produce seeds
+ Less space required
+ Lots of plants grown quickly compared to seeds
Arguments against artificial plant cloning
- Monoculture as they are identical meaning they are all vulnerable to the same diseases
- Expensive
- Contamination of microorganisms during tissue culture will cause every other clone to be infected
Natural cloning in animals
- Twins from zygote splitting form two embryos
- Starfishes can regenerate entire limbs
What are the two types of artificial cloning? in animals
- Artificial embryo twinning
- Somatic Cell Nuclear Transfer (SCNT)
What are the steps in embryo twinning?
- Egg cell is fertilised invitro
- Fertilised egg forms embryo
- Individual cells from the embryo are separated forming many different embryos
- Embryos are implanted into female surrogates
- Offsprings born are all genetically identical to each other
What are the steps in SCNT (Somatic Cell Nuclear Transfer)?
- A Somatic cell’s Nucleus is extracted
- The Extracted Nucleus is inserted into an enucleated ovum (nucleus less egg cell)
- This ovum is then stimulated to divide with an electric shock
- This produces an embryo
- This embryo is implanted into a surrogate mother
- A genetically identical copy of the original animal is made
Uses of animal cloning
- Research
- Agriculture
- Genetically modified organisms
- Clone Endangered animals
Arguments for Animal cloning
\+ High yield for agriculture \+ Infertile animals can still reproduce \+ Increase the population of endangered species \+ Clone-specific animals (pets) \+ Source of embryonic stem cells
Arguments Against animal cloning
- Expensive
- Don’t live as long as natural offspring
- Inefficient
- Reduces variability in the cloned populations
Use of microorganisms in biotechnology
- Brewing (yeast)
- Baking (yeast)
- Cheese
- Yoghurt
- Penicillin
- Insulin
- Bioremediation (removal of pollutants using microorganisms)
Why do we use microorganisms? (growth conditions, growth, cost)
- Ideal growth conditions can be easily created
- Short life cycle means RAPID growth
- Can grow on a range of inexpensive materials
Advantages of microorganisms in food culture
\+ No welfare issues \+ Grow quickly \+ High Protein content \+ Use waste materials to grow \+ Not dependent on breeding cycles weather etc
Disadvantages of microorganisms in food culture
- Other unwanted microorganisms can grow
- Unappealing to some people
- Not the same texture as real meat
- Toxins can be produced if conditions are not controlled
What are the two types of fermentation vessels?
- Batch fermentation
- Continuous fermentation
What are some risks in culturing microorganisms?
- Contamination
- Mutation
How can you culture microorganism using an agar plate? (aseptic conditions) (practical skills)
- Work underneath a bunsen burner (under flame)
- Sterilise the inoculating loop using a bunsen burner and let it cool
- Dip the sterilised loop into the bacterial solution and spread it on the agar
- Make sure to replace the lid quickly to reduce the chance of contamination
- Tape the lid but make sure oxygen can still enter the dish
What is batch fermentation?
- Microorganisms are grown in batches
What is continuous fermentation?
- Microorganisms are grown continuously without stopping
- Nutrients are put in and waste products are taken out at a continuous rate
Importance of maintaining and manipulating conditions to maximise yeild?
- pH (enzyme function)
- Temperature (enzyme function (maximise))
- Oxygen (Respiration)
- Nutrient concentration ( access to nutrients for growth)
- Prevention of contamination (Less competition for microorganisms more safe yield)
What is a closed culture?
- Extra nutrients are not added and waste products are not removed
Standard growth curve
- Lag phase (production of enzymes and other molecules before reproduction)
- Exponential log phase ( optimum condition for growth causing exponential growth)
- Stationary Phase ( Death rate = reproduction rate)
- Decline phase ( waste products are high and fewer resources leads to more death)
Formula for individual organisms given time and generations
N=N(initial) x 2^n
n= generations
How are enzymes immoblised?
- Adsorption to inorganic carrier
- Entrapment in a matrix
- Encapsulation
- Covalently bonded to cellulose or collagen fibres
Advantages for using immobilised enzymes
+ can be reused
+ Product does not contain the enzyme
+ More stable enzymes when immobilised
Disadvantages of using immobilised enzymes?
- Expensive to set up
- Reduced efficiency since they are immobilised
