Cloning and Biotechnology Flashcards
How do plans reproduce asexually?
Parts of the plant replicate by mitosis from stem cells (meristem).
How do strawberries reproduce?
The form runners which are horizontal stems that branch away from the plant and then form roots to reproduce asexually and form a clone.
What is a rhizome?
A branching stem from the reproducing plant that grows downwards to produce the clone
How are plant cuttings used to clone plants?
Cutting off non-flowering stem from the budding plant, dipping in plant hormones to encourage growth and fungicide then growing in soil.
How is micropropagation used to clone plants?
Taking only a tissue culture, sterilising the sample (e.g ethanol) and growing with hormones (auxins and cytokines) first on agar until roots have developed. A callus forms and is split into cells, transferred to a new agar plate. Eventually, plantlets that form are potted in soil.
What are the advantages of micropropogation?
- Rapid production of plants
- creates disease free plants
- can clone genetically modified plants.
- can clone seedless plants
- produce large numbers of rare endangered species
- can grow plants not easy to grow from seed
What are the disadvantages of micropropagation?
- expensive and requires skilled workers
- if the original cells have a viral infection, all the plats produced also will
- Monocultures are grown, reducing gene pool. They are all susceptible to the same diseases
What are a form of natural clones in animals?
Identical twins (monozygotic) originate from one zygote that splits into two or more to form identical offspring.
What is embryo twinning?
The process produces offspring that are clones of each other but not their parents. It has been routine procedure to boost livestock yield and promote desirable characteristics. It involves the purposeful splitting of an embryo from parents of desirable characteristics into many clones. These are inserted into uterus of host mothers.
What is somatic cell nuclear transfer?
-The animal to be cloned donates a somatic (body) cell (eg. from an udder)
- The egg cell is extracted from the egg donor and enucleated (its nucleus is removed by suction and discarded)
- The nucleus from the udder cell is injected into the enucleated egg cell
- The hybrid zygote cell is now treated with a small electrical current to encourage it to divide by mitosis
- The embryo is implanted into the surrogate mother for gestation and birth
What are the advantages of animal cloning?
- Animals with desirable characteristics will produce more offspring than with natural reproduction
- SCNT enables genetically engineered embryos to be cloned.
- Prticular animals can be clones (family pet, race horse)
- It could be used to increase the numbers of rare and endangered animals.
What are the disadvantages of animal cloning?
- SCNT is not efficient. 1 embryo is usually formed from many eggs.
- high miscarriage rate when implanting embryos from SCNT
- Animals produced by SCNT often have a shorter lifespan
What are the advantages of using microorganisms in biotechnology?
- Economic = tiny so can be grown in smaller spaces than animals. Their nutrient requirement is cheaper than animals. Can be grown at low temps, making harvesting cheaper.
- Short life cycle - food production is much faster than waiting for animals to grow
- Growth requirements are basic - warmth, water, oxygen and food. Reduces cost to grow them.
Where are microorganisms used in food production?
- Bread
- Brewing
- Cheese
- Yoghurt
How is bread made using microorganisms?
Yeast used for baking and the CO2 from its respiration makes bread rise
How are microorganisms used in brewing of alcohol?
Anaerobic respiration of yeast produces ethanol which is used to make alcoholic drinks
How is cheese made using microorganisms?
Bacteria uses milk as respiratory substrate, making it into curds (solids) and whey (liquid). Curds used to make cheese.
How is yoghurt made using microorganisms?
Bacteria produce ethanal or lactic acid which result in the milk forming polymers that give yoghurt a thicker and smoother texture.
How are microorganisms involved in medicine production?
Penicillin and insulin. Penicllin is an antibiotic produced by mould. The fungus is grown in fermenters, stirred with oxygen and nutrients and the penicillin produced is harvested and purified
What is bioremediation?
When microorganisms are used to digest pollutants and contaminants. Their growth can be encouraged (providing nutrients) to increase their population size to help break down pollution. E.g oil spillage cleaning
List the advantages of using microorganisms in biotechnology.
- They grow rapidly
- They can be genetically engineered
- They can be flavoured to taste like anything
- There are no ethical concerns about growing microbes
- They are rich in protein and low in fat (beneficial for foods made from them like quorn)
List the disadvantages of using microorganisms in biotechnology.
- Microbes can produce toxins if growing conditions are not carefully controlled
- Microbes must be grown in aseptic conditions
- Some people don’t like the idea of eating them
-Microbes have no natural flavour, so additive have to be used
How are microorganisms grown?
They require a growth medium (liquid nutrient broth or solid agar) that contains water and nutrients. They also require oxygen and are incubated at 25 degrees - warm enough for growth but below optimum temp to reduce risk of pathogens growing in large quantities.
Describe aseptic techniques needed to culture microorganisms.
- Sterilise all equipment to kill microbes - e.g flaming metal equipment in blue flame of busen burner
- Sterilise work surfaces using disinfectant
-Wash hands with soap to remove microbes - Work near a Bunsen burner - convection currents constantly sterilise the air
- Only open the Petri lid slightly and only when needed