cloning and biotechnology

Question 1

what regions of a plant is capable of vegetative reproduction

Answer 1

root and shoot tips
auxiliary buds (where leaves and stems meet)
vascular cambium (between xylem and phloem)

Question 2

outline the steps of taking a cutting

Answer 2

1. using a scalpel, take a cutting of a healthy stem between nodes from parent plant at a slant
2. remove leaves from lower end of cutting
3. dip the lower end in rooting powder
4. place plant in pot containing suitable growth medium
5. provide cutting with warm and moist environment by covering with a plastic bag
6. when roots have formed, place in soil.

Question 3

outline the steps of tissue culture

Answer 3

1. cells from stem and root tip are taken from the original plant
2. cells are sterilised with dilute bleach to kill any microorganisms.
3. cells are placed on a culture medium
4. should be carried out using aseptic conditions
5. cells are left to divide to produce a mass of undifferentiated cells called a callus
6. the mass is subdivided to produce many plants quickly, they are left to divide and grow then placed in soil.

Question 4

what are some advantages of cloning plants

Answer 4

can close plants that don’t easily reproduce or are endangered.
can grow plants with desirable characteristics which are always passed on
can grow plants in any season
less space is required compared to conventional growth methods
time efficient

Question 5

what are some disadvantages of cloning plants

Answer 5

no genetic variability so single disease can kill entire crop
contamination by microorganisms can be disastrous and result in complete loss of crop

Question 6

outline the process of artificial embryo twinning

Answer 6

1. an egg cell is extracted from the animal and fertilised in petri dish
2. fertilised egg is left to divide forming an embryo in vitro
3. individual cells from embryo are separated and each is placed into a separate petri dish. an embryo forms in each dish
4. embryo is then implanted into a surrogate mother where it continues to develop

Question 7

outline the process of somatic cell nuclear transfer

Answer 7

1. from sheep A a somatic cell is taken and the nucleus is extracted and kept.
2. an immature egg cell is taken from sheep B and its nucleus is removed to form an enucleated cell
3. nucleus from sheep A is inserted into the enucleated cell where they fuse together and stimulated to divide eg. by electrofusion
   this produces an embryo
4. the embryo is implanted into a surrogate mother

Question 8

what are some advantages of animal cloning

Answer 8

can test drugs on cloned animals as they are genetically identical therefore genetic variables are controlled.

can be used to increase the number of animals with desirable characteristics

an animal that has been genetically modified to produce a beneficial substance in it’s milk could be cloned.

clones can be used to save endangered animals from extinction

Question 9

what are some disadvantages of animal cloning

Answer 9

animal cloning has low success rates and is time consuming and expensive

no genetic variability therefore all clones are susceptible to disease

clones may have shorter lifespans and more health problems for example dolly the sheep had to be put down at 6 years due to severe arthritis

Question 10

what is biotechnology

Answer 10

the industrial use of living organisms to produce food, drugs ect.

Question 11

why are micro-organisms often used in biotechnology

Answer 11

their ideal growth conditions can be easily created
short life cycle so grow rapidly under right conditions
can grow on inexpensive materials eg. waste
can be grown any time of the year

Question 12

what microorganism is used to make beer

Answer 12

yeast

Question 13

what microorgamism is used in cheese making

Answer 13

bacteria

Question 14

what micro-organism is used to make yoghurt

Answer 14

bacteria

Question 15

what is bioremediation

Answer 15

process of using living organisms to remove pollutants such as oil and pesticides from contaminated sites

Question 16

what are primary metabolites

Answer 16

metabolites needed for growth of microorganisms during log/lag phase

Question 17

what are secondary metabolites

Answer 17

not needed for growth of microbes

Question 18

what is batch fermentation

Answer 18

where micro-organisms are grown in individual batches in a fermentation vessel. When one culture ends it is removed, the vessel is resteralised to avoid contamination. A different batch of microorganisms is then grown.

Question 19

what is continous fermentation

Answer 19

where micro-organisms are continually grown in a fermentation vessel, without stopping. Nutrients is put in and waste products taken out at a constant rate

Question 20

in pencillin production, which is more likely to be used, batch fermentation or continous

Answer 20

batch

Question 21

which type of metabolites are harvested during continous fermentation

Answer 21

primary

Question 22

which factors need to be controlled during fermentation

Answer 22

pH
temperature
oxygen supply
nutrient concentration
contamination

Question 23

what is downstream processing

Answer 23

the purification of the product that has left the fermenter

Question 24

which type of fermentation is there less downstream processing, why is this an advantage

Answer 24

continuous

means there is less time spent with the vessel off therefore product therefore more profit.

Question 25

what phase of a standard growth curve, are secondary metabolites produced

Answer 25

stationary phase - when there is a limiting factor.

Question 26

outline the lag phase of the standard growth curve

Answer 26

population size increases slowly micro-organisms are adjusting to the environment eg. making enzymes reproduction rate is low

Question 27

out line the log (exponential) phase of the standard growth curve

Answer 27

population size is increasing very quickly. conditions are at the most favourable for reproduction number of micro-organisms doubles at regular intervals

Question 28

outline the stationary phase of. the standard growth curve

Answer 28

population size stays level, birth rate = death rate. micro-organisms die as lack of food and waste products build up

Question 29

outline the decline phase of the standard growth curve

Answer 29

population size falls as death rate is greater than birth rate food is very scarce, excess waste products at toxic level.

Question 30

outline how u may set up culturing micro-organisms in a lab

Answer 30

- use a sterile innoculation loop to transfer some of the sample to the plate - using a glass spreader, spread the sample gently across the whole surface of the agar. - plate is incubated + left to grow

Question 31

outline aseptic technique

Answer 31

- regularly disenfect work spaces - work near a bunsen burner- creates an updraft so any micro-organisms in air should be drawn away from the culture - steralise instruments before and after by dipping in ethanol and passing through a bunsen burner - if using broth, briefly pass neck of broth container through flame after its opened and just before its closed - minimise the time the agar plate is open foor, placing lid on as soon as possible - steralise glasswear using an autoclave - wear lab coat and gloves

Question 32

what is the purpose of aseptic technique

Answer 32

used to avoid the contamination of unwanted organisms

Question 33

what is an immobalised enzyme

Answer 33

enzyme which is attached/ trapped into an inert matrix/material which prevents them from being mixed with the products

Question 34

what are the 4 main ways enzymes are immobalised

Answer 34

- entrapment - trapped in a silica gel matrix or cellulose fibres or can be trapped in a liquid eg. alginate beads - semi-permeable. (substrates and products must be small) - enzymes are covelantly bonded to a surface or other enzymes using a cross linking agent - this forms chains. (more expensive less likely to mix with reaction mixture) - adsorbtion - enzyme molecules are bound to a supporting surface by ionic links and hydrophobic interactions (could distort active site)

Question 35

what are the advantages of using immobalised enzymes

Answer 35

enzymes can be washed and reused which reduces cost product isn't mixed with the enzymes so no money/time spent separating them immobalised eznymes are more stable so less likely to denature at high temp/pH

Question 36

what are the disadvantages of using immobalised enzymes

Answer 36

- extra equipment needed - can be more expensive than isolated free enzymes immobilisation can sometimes lead to a reduction in enzyme activity as can't collide and interact with substrate as much

Question 37

what are isolated enzymes

Answer 37

enzymes out of the cell either naturally secreted (Extracellular) or artificially extracted