B22 - cloning & biotech Flashcards
Natural cloning in plants occurs in:
Bulbs: leaf bases swell w/ stored food; form internally; develop into new shoots
Runners:
lateral stem growth away from parent plant runs; roots develop where runner touches ground
Rhizomes:
Horizontal stem growth underground swollen w/ stored food. Buds develop and form new vertical shoots
Stem tubers:
- Tip of underground stems swell w/ stored food
- forms tuber/storage organ
- buds develop into new shoots
micropropagation in plants
large numbers of genetically identical offspring made from a single parent plant
reasons for micropropagation in plants
- rare
- required to be ‘pathogen free’
- doesn’t readily produce seeds
- doesn’t respond well to natural cloning
micropropagation in plants , steps:
1) remove explant (small sample) FROM MERISTEM
2) sterilise sample in ethanol to avoid contamination by bacteria or fungi
3) Place in sterile culture medium (auxins & cytokinins stimulate mitosis). 4) Cells proliferate & form callus
5) callus split into clumps and transferred into new culture medium containing diff hormones, stimulating development of plantlets
6) Plantlets potted into compost & grow into small plants
micropropagation in plants disadvantages
- creates monoculture (genetically identical plants) = susceptible to same disease & easily wiped out
- expensive process as required skilled workers
natural cloning in invertebrates
- starfish can regenerate damaged fragments
- hydra produce small buds which develop into identical clones
- flatworms & sponges fragment into new identical clones of parent plant
somatic cell nuclear transfer
1) nucleus removed from somatic cell of adult
2) nucleus removed from mature ovum of different female animal in same species
3) nucleus of somatic cell placed into enucleated egg cell & given electric shock so they fuse together and begins to divide
4) Developed embryo transferred into uterus of third animal (surrogate mother)
5) New animal = clone of animal from original somatic cell (although mitochondrial DNA comes from mother, it’s only involved in respiration and doesn’t affect actual phenotype)
define biotechnology
applying biological organisms/ enzymes to the synthesis, breakdown, or transformation of materials IN THE SERVICE OF THE PEOPLE
advantages of microorganisms in food production
- no welfare issues
- can be genetically engineered
- reproduce fast/ rapid growth rate due to short life cycle
- simple/cheap nutrient requirements = saves energy, money, less waste etc.
- low temp conditions, O2 supply, food,
- provide their own catalysts (enzymes) = cheap
disadvantages of microorganisms in food production
- Need ideal conditions to grow, or don’t work efficiently
- Ideal conditions could also be ideal conditions for other microorganisms that cause food to go off and cause disease
- processes must be STERILE
QUORN
- SCP (single-cell protein)
- made from fungus grown in large fermenters
- combined with albumin (egg whites) and compressed into meat substitutes
- high in protein, low in fat = healthy
- V. successful marketing
bioremediation
microorganisms used to break down/neutralise pollutants & contaminants in soil or water
Producing penicillin
- Needs high O2 & rich nutrient medium
- sensitive to temp and pH
- semi-continuous batch process used
- uses smaller fermenters as is easier to maintain high O2
- buffer solution & rich nutrients in growth medium
- penicillin extracted from medium & purified
Inoculating (liquid) broth
1) Make suspension of bacteria to be grown
2) mix known vol w/ sterile nutrient broth
3)stopper flask w/ cotton wool to prevent contamination from air
4) Incubate at suitable temp & shake regularly to aerate broth
Inoculating (solid) agar
STREAKING
- sterilise wire inoculating loop (hold under bunsen flame until red hot)
- Don’t touch to avoid contamination
2) Dip in bacterial suspension
3) remove petri lid and make zig zag patterns on agar
4) avoid loop digging into agar so that agar surface remains intact
5) Replace lid of petri dish, but don’t seal completely so that air can still enter
