Mr Dewhurst- cloning and biotechnology

Question 1

what is a clone

Answer 1

genetic copy of other organisms

Question 2

what is tissue culture

Answer 2

grow new tissue, organ or plant from certain tissues cut from sample plants

Question 3

what is micro propagation

Answer 3

growing large numbers of plants from meristem tissue taken from a sample plant

Question 4

when is micro propagation used

Answer 4

when a plant doesn’t produce seeds, rare plants, selectively breed plants/ genetically modify, if plant is pathogen free.

Question 5

what is the process of micropropagation

Answer 5

cells taken from meristem- shoot (explant)
cells sterilised before being placed onto nutrient medium
explant forms callus which divides to produce lots of small clumps of undifferentiated cells
plant hormones added to differentiate clumps into small plantlets
when plantlets are strong enough they are then transferred into compost

Question 6

what are some advantages of cloning plants

Answer 6

seedless fruits produced
rapid compared to seeded growth
disease free plants
increased number of rare plants
naturally infertile plants can be grown

Question 7

what are some disadvantages of cloning plants

Answer 7

monoculture- susceptible
to disease/growing conditions
expensive - skilled workers
explants and plantlets are vulnerable to mould
if source is infected less is.

Question 8

what is an advantage of asexual reproduction

Answer 8

don’t need a mate
pass on advantageous alleles
rapid conditions for parents are good for offspring

Question 9

what are disadvantages of asexual reproduction

Answer 9

lack variation- susceptible to disease
change in conditions- cannot adapt to new environment
selection not possible
offspring may be overpopulated

Question 10

what is vegetative propagation

Answer 10

plants that reproduce asexually e.g., strawberry’s have runners that go underground creating daughter plants that sprout out

Question 11

what are the different types of vegetative propagation

Answer 11

suckers- old branch dies-new branch replaces
tubers- stem underground
spider plants
corms
bulbs
leaves- clones grow in leaf margins

Question 12

what is biotechnology

Answer 12

using microorganisms to make products

Question 13

what are advantages of using microorganisms

Answer 13

no welfare issues, make variety of nutritious foods( less fat), less waste, quick, can be made anywhere, production can meet demand

Question 14

what are disadvantages to using microorganisms

Answer 14

needs to be specific conditions, contamination- bacteria not meant to be growing has the perfect conditions. protein needs to be separated, some people don’t like taste/texture

Question 15

what is the brewing process

Answer 15

yeast respires anaerobically to produce ethanol and co2
malting-enzyme from barely breaks down yeast
mash, ferment, mature then filter

Question 16

how is yeast used for baking

Answer 16

glucose +oxygen= carbon dioxide and water
carbon dioxide produced makes bread rise
hot oven causes the coz to rise and yeast expands

Question 17

what is the cheese making process

Answer 17

bacteria are fed on lactose which is a sugar found in milt to produce lactic acid
lactose- lactic acid which lowers PH
pasteurised ( heated milk)- kill bacteria
bacterial chymosin added to separate milk causing it to curdle

Question 18

how is yogurt produced

Answer 18

lactose broken down to lactic acid
pasteurise milk. add lactobacillus , incubate
add flavours and colouring.

Question 19

outline penicillin production

Answer 19

produced by batch culture - only produced when population reaches certain size - secondary metabolite
fermenters run for 6 days
filtered to remove cells
potassium compounds added and penicillin precipitated as crystals

Question 20

outline insulin production

Answer 20

previously extracted from a pig but now synthetic insulin is produced by genetically modified bacteria and gene for insulin inserted into plasma of vector

Question 21

what us bioremediation

Answer 21

use of microorganisms to clear polluted sites - converts toxic substances into less harmful ones
has to have suitable conditions such as water, temp, PH, oxygen at correct levels if not ex situ treatment will take place

Question 22

explain what singe cell proteins are

Answer 22

microorganisms produce proteins for human consumption e.g., Quorn
many different fungi can be used to create proteins with similar amino acid profiles as plants/animals

Question 23

what is the first stage of bacterial growth curve

Answer 23

lag phase- slow growth where yeast has to synthesis enzymes to break sucrose into glucose+ fructose

Question 24

what is the second stage of bacterial growth curve

Answer 24

exponential /log phase- all nutrients etc. in plentiful supply so is fastest

Question 25

what is the third stage of bacterial growth curve

Answer 25

stable/stationary state where resources become the limiting factor and there is a build up of waste products

Question 26

what is the fourth stage of bacterial growth curve

Answer 26

death where resources are all used up and waste is built up to a toxic level

Question 27

what are some examples of limiting factors which prevent exponential growth in a culture of bacteria

Answer 27

nutrients- used up with increase amount of microorganisms oxygen levels- pop rises so does need for respiratory oxygen temperature- enzyme controlled reaction build-up of waste- may inhibit growth change in PH- effects enzyme activity

Question 28

what is batch fermentation

Answer 28

microorganisms are inoculated (added) nutrients used up- waste builds up when stationary phase is hit, growth of microorganisms stop but microbes carry out biochemical processes to produce desired products (secondary metabolite) process stopped at death phase

Question 29

what are some advantages of batch fermentation

Answer 29

less monitored only loose one batch if contaminated most time in expediential growth

Question 30

what is continuous fermentation

Answer 30

sterile nutrients added continuously at stationary phase waste removed only really making primary metabolites

Question 31

what are some disadvantages to continuous fermentation

Answer 31

more expertees, more likely to get contamination by adding new nutrients in constanlty if whole batch ruined it is expensive most time in stationary phase

Question 32

what are primary metabolites

Answer 32

made at any point of process

Question 33

what are secondary metabolites

Answer 33

made at certain stages

Question 34

what are immobilised enzymes

Answer 34

enzymes that don't move as they are attached to a substrate to hold it in place.

Question 35

what are some advantages o immobilising enzymes

Answer 35

saves money- reuse enzyme milk not contaminated with enzyme less effected by fluctuations in pH and temp

Question 36

what is the absorption method of immobilising enzymes

Answer 36

ionic and hydrophobic interactions hold enzyme in place which is bound to supporting surface

Question 37

what are some advantages and disadvantages of the absorption method

Answer 37

adv- active sites are accessible to substrate -- can distort active site- reducing activity -- bonding forces may not be strong enough so enzymes wash into milk

Question 38

what is the covalent bonding method of immobilising enzymes and advantages and disadvantages

Answer 38

strong bonds to bind enzyme to supporting surface e.g., clay stays in place- less likely to wash off/ active sites accessible -- expensive and can distort active site

Question 39

what is entrapment method of immobilising enzymes and some advantages and disadvantages

Answer 39

enzyme is trapped in gel +- less chance of active site being distorted - remains active - active sites are less accessible so takes longer for substrate to diffuse in and out of gel

Question 40

what are good about immobilized enzymes in terms of PH and temp

Answer 40

temp- work at higher temperatures before denaturing which means they are more tolerant to temp changes PH- can be less concerned about PH fluctuations so less control is needed