6.4 cloning and biotechnology

Question 1

define clone

Answer 1

genetically identical organism or cell produced by asexual reproduction and mitosis

Question 2

advantages of natural cloning

Answer 2

if conditions for growth are good for the parent theyll be good for the offspring
cloning is rapid
reproduction can occur if only one parent available

Question 3

disadvantages of natural cloning

Answer 3

offspring may become overcrowded
no genetic diversity (unless mutation)
little variation in population
selection is not possible
if the environmental conditions change the whole population is susceptible

Question 4

define vegetative propagation

Answer 4

process of reproduction through vegetative parts of a plant to produce natural clones

Question 5

name the different forms that a plant can reproduce to make natural clones

Answer 5

runners / stolons - horizontal stems that form from roots
rhizomes - horizontal stem but underground
suckers - new stems that grow from the roots of a plant
bulbs - over wintering mechanism, underground stem where new fleshy bases grow
corns - solid underground stem with scaly leaves and buds
leaves - clones grow on leaf margins (kalanchoe plant)
tubers - another type of underground stem (potato)

Question 6

name a simple cloning technique

Answer 6

plant cuttings (between two nodes)

Question 7

how to take plant cuttings

Answer 7

stem is cut between two leaf joints (nodes)
placed into moist soil
new roots will grow from the tissues in the stem

Question 8

name ways of artificially producing clones in plants

Answer 8

tissue culture
micropropogation

Question 9

define tissue culture

Answer 9

growing new tissues, organs or plants from a small sample of cells or tissue

Question 10

why is tissue culture used

Answer 10

commercially to increase the number of new plants in micropropagation

Question 11

define micropropagation

Answer 11

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

Question 12

steps of micropropagation

Answer 12

plant material is selected and cut into small pieces (called explants)
explants are sterilised
placed onto a sterile growth medium containing suitable nutrients and plant growth hormones
stimulates cells to divide by mitosis to form a callus
callus is divided and the small clumps are stimulated to differentiate into different plant tissues
stimulates shoots to form which is then transferred to a greenhouse

Question 13

advantages of artificial cloning

Answer 13

rapid method
carried out where sexual reproduction is not possible
displays same desirable characteristics
combination of characteristics retained as not lost through sexual reproduction
easier to grow and harvest
apical bud (meristem) used so free from virus

Question 14

disadvantages of artificial cloning

Answer 14

tissue culture is labour extensive
expensive to set up facilities to perform it successfully
can fail due to microbial contamination
all cloned offspring are genetically identical

Question 15

what type of cells are used in artificial cloning in animals

Answer 15

totipotent cells from embryos

Question 16

name the techniques used for artificial cloning in animals

Answer 16

embryo twinning
somatic cell nuclear transfer

Question 17

explain how embryo splitting works

Answer 17

a zygote (fertilised egg) is produced by IVF
divides by mitosis into a small ball of cells
cells are separated and allowed to continue dividing
placed into a surrogate mother

Question 18

what is somatic cell nuclear transfer works

Answer 18

the cloning of an adult

Question 19

explain how somatic cell nuclear transfer occurs

Answer 19

an egg cell is obtained and the nucleus is removed (enucleation)
normal body cell from the adult being cloned is enucleated
the nucleus is fused with the egg cell by applying an electric shock
the shock triggers the egg cell to start developing
the cell undergoes mitosis to produce a small ball of cells
young embryo is placed into the uterus of a surrogate mother

Question 20

define non reproductive cloning

Answer 20

production of cloned cells and tissues for purposes other then reproduction

Question 21

uses of artificical cloning

Answer 21

therapeutic cloning - new tissues and organs can be grown
scientific research - into action of genes that control differentiation

Question 22

arguments for artificial cloning in animals

Answer 22

can produce a whole herd of animals with a high yield
produces genetically identical copies that retain characteristics
useful for scientific research as genotypes are the same
testing medicinal drugs on animals
can medically repair damaged tissues
increases numbers of endangered animals

Question 23

arguments against artificial cloning in animals

Answer 23

lack of genetic variation = exposed to diseases
success rate is poor
expensive
ethical issues with regards to embryo use

Question 24

advantages of using microorganisms in biotechnology

Answer 24

cheap and easy to grow
production takes place at lower temps = saves costs and fuels
can take place at normal atmospheric pressure
production is not dependant on the climate
microorganisms can be fed by products from other food industries
have a short life cycle and can reproduce quickly
can be easily genetically modified
fewer ethical considerations
product easy to harvest

Question 25

define biotechnology

Answer 25

the use of living organisms in industrial processes

Question 26

examples of what microorganisms can be used to make in biotechnological processes

Answer 26

yoghurt cheese baking bread alcoholic beverages proteins

Question 27

advantages of using microorganisms in food production (protein)

Answer 27

production of protein is quicker then in plants/animals biomass produced has a higher protein content production can be increased due to demand no animal welfare issues no animal fat or cholesterol

Question 28

disadvantages of using microorganisms in food production

Answer 28

eating fungal protein or food is unpopular protein needs to be isolated - uses larger fermenters protein needs to be purified may contain different amino acids to normal may become infected doesnt taste of traditional protein sources

Question 29

what are fermenters used for

Answer 29

commercial drug production uses large stainless steel containers to control growing conditions and ensure the best yield of product

Question 30

what conditions are controlled in a fermenter

Answer 30

temperature nutrient availability oxygen availability pH product concentration

Question 31

explain the difference between batch and continuous culture

Answer 31

continuous - product is produced and removed regularly as the broth is continually topped up with nutrients etc. batch - culture set up with a limited amount of nutrients and is left to ferment and after the fermenter is emptied and product is extracted

Question 32

explain the importance of asepsis in fermenters

Answer 32

sterile conditions maintained as unwanted microorganisms would compete with the cultured microorganisms for nutrients and space reduces the yield of the useful products and spoil them produce toxic chemicals and potentially destroy the cultured microorganism

Question 33

name the different types of growth mediums

Answer 33

broth agar

Question 34

define aseptic techniques

Answer 34

sterile techniques used in culturing and manipulating microorganisms

Question 35

procedure of aseptic techniques

Answer 35

wash hands disinfect work area use a bunsen burner to create convection to prevent air bourne microorganisms, create area of sterile air pass neck of open bottles through the flame and as its closed don't lift the lid of the petri dish completely pass equipment through flame

Question 36

name the steps involved in growing microorganisms on agar plates

Answer 36

sterilisation inoculation incubation

Question 37

explain the process of sterilisation

Answer 37

autoclave used to sterilise agar medium and equipment and use heat from bunsen burner flame during

Question 38

explain the process of inoculation

Answer 38

the way of introducing microorganisms to a sterile medium streaking - wire inoculating loop to transfer liquid seeding - sterile pipette spreading - a glass spreader used to spread out the microorganism

Question 39

explain the process of incubation

Answer 39

petri dish labelled and taped lightly placed in an incubator upside down

Question 40

explain how serial dilutions can be used with liquid broth

Answer 40

serial dilutions reduce the population density of microorganisms by diluting the solution by a factor of ten in a liquid broth to make them easier to count colonies

Question 41

define serial dilution

Answer 41

a sequence of dilutions to reduce the concentration of a solution or suspension

Question 42

define closed culture

Answer 42

a culture which has no exchange of nutrients or gases with the external environment

Question 43

explain the shape of the growth curve

Answer 43

lag phase - flat at the beginning exponential phase/ log phase - line begins to curve/ gets steeper stationary phase - line plateaus again death/ decline phase - line declines

Question 44

explain each phase of the growth phase

Answer 44

lag = early population growth is slow as the micro. are adjusting to the new environment log = micro. have adjusted to the environment, population grows rapidly stationary = rate of pop. growth begins to equal death rate decline = nutrients run out, waste products may become lethal. pop. declines

Question 45

explain the difference between primary and secondary metabolites

Answer 45

p = produced during normal activities, collected from a fermenter during the log phase s = produced in the secondary phase, collected at the end or during decline

Question 46

define immobilised enzymes

Answer 46

an enzyme that is held in place and not free to diffuse through the solution

Question 47

advantages of using immobilised enzymes

Answer 47

extraction costs are lower as they don't mix with the product enzymes can be reused continuous production is easier enzymes are surrounded by a matrix so they are protected from extreme environments

Question 48

explain the 3 ways of immobilising enzymes

Answer 48

adsorption - bound to a supporting surface by hydrophobic and ionic links covalent bonding - bonded to a supporting surface using strong covalent bonds entrapment - trapped in a matrix and the substrate and product diffuses in and out

Question 49

name industrial uses of immobilised enzymes

Answer 49

glucose isomerase - converting glucose to fructose lactase - converting lactose to glucose and galactase for lactose free milk formation of semi synthetic penicillins