Biotechnology and Gene Technologies Flashcards
What are the advantages of asexual reproduction?
- It is quick, allowing organisms to reproduce rapidly and so take advantage of resources in the environment.
- It can also be completed if sexual reproduction fails or is not possible.
- All offspring have the genetic information to enable them to survive in their environment.
What are the disadvantages of asexual reproduction?
- It does not produce any genetic variety, so genetic parental weakness will be in all the offspring.
- Not able to adapt to environmental changes.
What is the definition of vegetative propagation?
Production of structures in an organism that can grow into new individual organisms. These offspring contain the same genetic information as the parent and so are clones of the parents.
What is an example of a plant that can asexually reproduce?
The english elm tree
How are the english elm tree able to adapt to reproduce asexually?
When there are damages to the parent plant (e.g disease or burning)
New growths in the form of root suckers to basal sprouts, appear within 2 months of the damage of the main trunk. They grow from meristem tissue close to the ground.
What are the advantages of elm vegetative propagation?
- Root suckers help the elm spread because they can grow all around the original trunk. (clonal patch)
What are the disadvantages of elm vegetative propagation?
When dutch elm disease hits the trees, the new trees got to about 10cm in diameter and became infected and died. Because they are clones they do not have any resistance to the disease.
- No genetic variation so natural selection cannot occur.
How are farmers able to artificially propagate valuable plants?
- Taking cuttings
- Grafting
- Tissue culture
Why is tissue culture better?
Used to generate large stocks of a particularly valuable plant very quickly, with the added advantage that these stocks are known to be disease-free.
What are the steps of micropropagation?
- A small piece of tissue is taken from the plant to be cloned (explant).
- The explant i placed on a nutrient growth medium.
- Divide into a mass of undifferentiated cells called a callus.
- Callus are placed on a growth medium containing plant hormones that encourage shoot growth.
- Transferred to a different one.
- Transferred to a greenhouse before being planted outside.
What are the advantages of plant cloning in agriculture?
- High-quality crops in terms of yield and resistance produced.
- Know what plant is going to be produced.
- Costs are lower
- Quicker
What are the disadvantages of plant cloning in agriculture?
- Equally susceptible to any new pest, disease or environmental change.
What is reproductive cloning?
- Whole individual animal is cloned from another animal.
- The purpose of reproductive cloning is to generate individuals with desirable features.
What is non-reproductive cloning?
- This is when embryonic cells could be used to clone specific tissues and organs.
- The purpose of non-reproductive cloning is to treat damage caused by diseases or accidents.
What is embryo splitting?
- Nucleus comes from an egg fertilised during IVF.
- Embryos produced are clones of the original zygote.
- Mitochondrial DNA will be identical in each clone and identical to the original egg cell.
What is nuclear transfer?
- Nucleus comes from an adult cell.
- Embryo produced are clones of the donor.
- Mitochondrial DNA will not be identical to the donor organism.
What are examples of non-reproductive cloning?
- The regeneration of heart muscle cells following a heart attack.
- The repair of nervous tissue destroyed by diseases such as MS.
- Repairing the spinal cord of those paralysed by an accident that resulted in a broken back or neck.
What are advantages of animal cloning?
- High-value animals, for example cows giving high milk yield, can be cloned in large numbers.
- Rare animals can be cloned to preserve the species.
- Genetically modified animals- for example sheep that produce pharmaceutical chemicals in their milk- can be quickly reproduced.
What are disadvantages of animal cloning?
- High-value animals are not necessarily produced with animal welfare in mind. Some strains of meat-producing chickens have been developed that are unable to walk.
- Excessive genetic uniformity in a species makes it unlikely to be able to cope with, or adapt tom changes in the environment.
- It is unclear that they will be healthy in the long term.
Why are microorganisms often used in biotechnology?
-Grow rapidly = large quantities of product in a short time
- Produce pure products (often more pure than from chemical processes) = less down stream processing
-Not dependant on climate so can grow anywhere
- Easy to genetically engineer = make many products /human products
- Do not require high temperatures = low costs
- Easy to harvest products = low costs
- Can grow on waste materials = low costs & environmental advantages
What are the phases of a standard growth curve?
Lag
Log
Stationary
Death
What happens in the lag phase?
- Organisms are adjusting to the surrounding conditions
- Cells active but not dividing so population fairly constant
- Synthesis of inducible enzymes and factors involved in cell division
What happens in the log phase?
-Population doubles with every generation o High levels of nutrients o Low levels of waste o low levels of competition o few limiting conditions
What happens in the stationary phase?
-Birth rate = death rate so population is stable
o Nutrient levels are dropping
o Waste levels are rising
o Competition is rising
What happens in the death phase?
-Greater number dying than being produced
o Nutrient levels are low
o Waste levels are high
o Competition is high
State the properties of primary metabolites.
Produced as part of normal growth o Essential for life o Produced in line with growth curve o Example: insulin / amino acids / fatty acids / lipids / enzymes. o Produced using a continuous culture o Highest production in the Log phase.
State the properties of secondary metabolites.
Not produced as part of the normal growth
o Not essential for life.
o Only start to be produced in the stationary phase when nutrients are in short supply and competition is high.
o Example: penicillin
o Produced using a batch culture.
o Highest production in stationary phase.
What are facts about batch culture?
Used to produce secondary metabolites
o Everything sterilised and added at the start then left.
o Small quantities of nutrients are added throughout to maintain the stationary phase.
-Not too much = log phase
- Not too little = death/decline phase
What are facts about continuous culture?
Used to produce primary metabolites
o Everything sterilised and added continuously to maintain the log phase.
o Oxygen, p.H and temperature are constantly monitored
Does BC or CC have a better growth rate?
CC because nutrients are added and waste removed continuously, whereas BC nutrients are decreasing and waste is increasing.
Does BC or CC have a better efficiency?
BC- Less as not in operation all the time
CC- More as in operation all the time
Does BC or CC have better yield?
BC- Only 1 batch is lost
CC- Huge volumes of product is lost
Is BC or CC easier to set up?
BC- Easy to set up and maintain
CC- Difficult to setup and maintain