Chapter 22-Cloning Biotechnology

Question 1

How do plants reproduce?

Answer 1

Both sexually and asexually

Question 2

What are meristems

Answer 2

due to their natural asexual reproduction, there are parts of plants that replicate by mitosis from stem cells, these are known as meristems

Question 3

Strawberries form runners, what are runners?

Answer 3

horizontal stems that branch away from the plant, then form roots to reproduce asexually and form a clone.

Question 4

in some plants, the horizontal stem grows underground.
what is this called?

Answer 4

Rhizome

Question 5

how has natural cloning in plants been made use of in horticulture?

Answer 5

it means new plants can be made for free ( as it is natural) and quickly (as they are not germinating from seeds).
Another reason is that farmers can clone plants that have desirable characteristics.

Question 6

Outline the method of taking plant cuttings.
plant cuttings is an example of natural plant cloning.

Answer 6

cut off a non flowering stem from budding plant
dip it in plant hormone root powder (to encourage growth) and fungicide to prevent infection.
grow into soil

Question 7

Micropropagation is an artificial plant cloning technique. It is used to produce plants when a desirable plant:

Answer 7

-does not readily produce seeds
-is very rare
-doesn’t respond well to natural cloning
-genetically modified or selectively bred
-pathogen free ( eg strawberries, potatoes and bananas)

Question 8

Outline the process of Micropropagation?
(artificial plant cloning)

Answer 8

Take a tissue culture
sterilise the sample (eg with ethanol)
Grow with hormones (auxins and cytokines) on agar first until roots have developed.
A callus forms
This callus splits into cells and is transferred to a new agar plate
The small plantlets that form are plotted into the soil where they grow into small plants.
the young plants are planted out to grow and produce a crop.

Question 9

List advantages of Micropropagation?
(six)

Answer 9

-Rapid production of plants
-creates disease free plants
-can clone genetically modified plants
-can clone seedless plants such as seedless varieties of grapes
-produce a larger number of rare or endangered plants
-can grow plants that do not grow from seed easily

Question 10

List disadvantages of Micropropagation
(six)

Answer 10

1) expensive and requires skilled workers
2)if original cells have viral infections, all the plants produced will have a virus too.
3) Monocultures are grown and gene pool is reduced so all plants are susceptible to the same diseases
4) reduced gene pool, reduced genetic diversity of the cloned plants (reduces likelihood of survival)
5) in some cases, large number of new plants are lost in the process
6) explants and plantlets vunerable to infection by moulds and other diseases during production process.

Question 11

Identical twins (monozygotic) are a form of natural cloning in animals.
outline how.

Answer 11

from one original zygote, an embryo forms which splits into two or more embryos to form identical offspring.

Question 12

Give an example of natural cloning in invertebrates.

Answer 12

entire starfish can can regenerate from fragments of original starfish

Question 13

Embryo Splitting, artificial animal cloning can be used to maintain desirable characteristics in offspring.
Outline this process

Answer 13

-two parents with desirable characteristics such as two healthy cows with a female that produces nutrient rich milk, are selected.
-The female is given hormones to produce many eggs.
-samples of their egg and sperm are used in in vitro fertilisation in the lab.(sometimes the eggs are naturally fertilised)
when an egg cell is fertilised and an embryo forms , the embryo is split apart into many single,identical cells
-the identical cells are inserted into the uterus of different host mothers, all the offspring will be clones of each other but not of the parents.

Question 14

A second method to artificially clone animals is called somatic cell nuclear transfer.
SCNT
Outline this process

Answer 14

A somatic cell (body cell) is taken from animal that you wish to clone.
An egg cell is taken from a female and the nucleus is removed and discarded.
The nucleus is removed from the somatic cell and inserted into empty egg cell.
A small electrical current is applied to make the egg cell start to divide to form an embryo.
Once the embryo is a bundle of cells, the cells are separated and inserted into the uterus of different host mothers
Each of these inserted cells is genetically identical to the other and also to the animal that the nucleus came from.

Question 15

what was the first animal to be produced by SCNT

Answer 15

Dolly-
healthy but had a shorter life span.
unknown why SCNT animals have a shorter life span but linked to fact that they have been created from older adult DNA which has already aged.

Question 16

List the advantages of animal cloning.
(four reasons)

Answer 16

-Animals with desirable characteristics will produce more offspring than with natural reproduction
-SCNT enables genetically engineered embryos to be cloned.
-Animals can be cloned e.g family pets, race horses
-used to increase number of rare or endangered animals

Question 17

disadvantages of Animal cloning
(three reasons)

Answer 17

-SCNT not very efficient as usually one embryo is formed from many eggs.
-high miscarriage rate when implanting embryos from SCNT.
-animals produced from SCNT have shorter lifespans.

Question 18

Human population is continuously increasing, demand for food is increasing at a rate that cannot be matched by space and time for farming animals.
microbes such as bacteria and fungi can be used to help meet this increased demand in food.
(list reasons why)

Answer 18

1) economical advantage-microbes are very tiny so can be grown in smaller spaces than animals. cheaper nutrient requirements than animals. grow at low temperatures making harvesting them cheaper.
2) microbes have a very short life cycle, bacteria reproduce every 20 minutes so food production much faster than waiting for animals to grow.
3) basic growth requirements- only need warmth, water, food and oxygen . reduces costs making them easier to grow.

Question 19

what have micro-organisms been used in food production to make

Answer 19

-bread- yeast used for baking, when yeast respire, they produce carbon dioxide which makes bread rise
-brewing-yeast respiring anaerobically produce ethanol
-cheese- bacteria use lactose in milk as respiratory substrate. this causes milk to separate into curds (solids) and whey (liquids). the curds are used to make cheese
-yoghurt- bacteria produce ethanal or lactic acid which results in the milk forming polymers that give yoghurt thicker and smoother texture.
-mycoprotein (quorn fungus fusarium venetatum is grown and used to make quorn)

Question 20

How are microorganisms used in medicine?
(three ways)

Answer 20

-penicillin
-insulin
-bioremediation

Question 21

what is penicillin

Answer 21

an antibiotic produced by the mould penicillin notatum, but penicillin chrysogenum produces a higher yield of penicillin. the fungus is grown in fermenters, stirred with oxygen and nutrients and the penicillin produced is harvested and purified.

Question 22

what is insulin

Answer 22

produced by genetically modified bacteria which have the human gene for insulin inserted into one of their plasmids.

Question 23

what is bioremediation

Answer 23

microorganisms are used to digest pollutants and contaminants. naturally occurring microbes break down crude oil and sewage (pollutants) .
microbial growth can be encouraged by providing them with nutrients to increase their population size to help break down pollution. this is a common technique for contamination sites such as oil spillages. genetically modifying bacteria to increase the range of pollutants they break down.

Question 24

Advantages of using Micro-organisms in biotechnology
(five reasons)

Answer 24

-microbes grow rapidly
-microbes can be genetically engineered
-microbes can be flavoured to taste like anything
-no ethical concerns about growing microbes
-microbes are rich in protein but low in fat (quorn)

Question 25

Disadvantages of using microbes in biotechnology

Answer 25

-microbes can also 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 microbes
-microbes have no natural flavour, so additives have to be used.

Question 26

how are microorganisms cultured

Answer 26

microbes must be grown in a growth medium (solid agar, nutrient broth) contains water and nutrients, require oxygen and at schools incubated at 25,must work aseptically.

Question 27

what does aseptic techniques mean?

Answer 27

working in sterile conditions to prevent contamination and infection of others

Question 28

List six aseptic techniques

Answer 28

-sterilise all equipment to kill microbes (use autoclave)
-sterilise work surfaces with disinfectants to kill microbes
-wash hands with soap to remove any microbes
-work near a bunsen burner as convection currents continually sterilise the air
-only open the petri dish lid slightly and only when necessary.
sterilise all equipment to kill microbes (flaming metal equipment through the blue flame of a bunsen burner)

Question 29

topic standard growth rates:
bacteria reproduce rapidly (every 20 minutes), large quantities are obtained rapidly
we use a log scale when we have a very large range of values
what is the formula to work out number of individual organisms.

Answer 29

N=N(0) x 2^n
N(0)= initial number of bacteria
n= number of divisions or generations

Question 30

list the four stages of a standard growth curve

Answer 30

stage 1:Lag phase
stage 2: Exponential Phase
stage 3: Stationary phase
stage 4: Death phase

Question 31

Describe the lag Phase

Answer 31

1) number of bacteria is lower, while bacteria are adjusting to their new environment

Question 32

Describe the exponential Phase

Answer 32

once the bacteria are reproducing at their maximum rate, the increase in the number of bacteria is represented by the exponential phase.

Question 33

Describe the stationary phase

Answer 33

reaches a point where the number of bacteria from growth is equal to number of bacteria that dies, resulting in a constant population size.

Question 34

Describe the death phase

Answer 34

number of bacteria decreases because number of deaths exceeds the reproductive rate, this could be because toxins build up or resources are running out.

Question 35

How can the death phase be prevented

Answer 35

manipulating growing conditions to remove limiting factors.
1)ensuring plenty of nutrients are available and constantly added.
2)increasing oxygen available to ensure that aerobic respiration continues
3)maintaining the temperature- as the population of respiring bacteria increases, temperature will increase leading to enzymes denaturing.
4) buffering PH
5) removing toxins such as ethanol

Question 36

whats an alternative to using micro-organisms

Answer 36

-immobilising enzymes
-isolate enzymes within microorganisms and isolate them

Question 37

whats the advantage of immobilising enzymes compared to using microorganisms

Answer 37

-immobilising enzymes is more efficient, more specific and no growth mediums are required.

Question 38

what are immobilised enzymes

Answer 38

enzymes required is fixed to an inert substance and the substrate is passed over it.

Question 39

how is the process of immobilising enzymes beneficial

Answer 39

dont need to purify the enzyme from the end product as it remains attached to the inert object.
they can easily be reused which saves money.
having the enzymes fixed also decreases sensitivity to temperature changes so high temperatures can be used to increase the rate of reaction without enzymes denaturing.

Question 40

whats the disadvantages to immobilising enzymes

Answer 40

upfront costs for materials and bioreactors and is more technical

Question 41

list some uses of immobilised enzymes in biotechnology?

Answer 41

glucose isomerase for the conversion of glucose to fructose
lactase for hydrolysis of lactose to glucose and galactose
amino acylase for the production of pure samples of L amino acids.
penicillin acylase for the formation of semi synthetic penicillins (to which some penicillin resistant organisms are not resistant)
glucoamylase for the conversion of dextrins to glucose.

Question 42

immobilised aminoacylase definition

Answer 42

immobilised enzyme used to produce pure samples of L amino acids

Question 43

immobilised glucoamylase definition

Answer 43

immobilised enzyme used to break down dextrins into glucose

Question 44

immobilised glucose isomerase definition

Answer 44

an immobilised enzyme used to convert glucose into fructose

Question 45

immobilised lactase definition

Answer 45

an immobilised enzyme that hydrolyses lactose into glucose and galactose in the production of lactose free milk.

Question 46

immobilised penicillin acylase

Answer 46

an immobilised enzyme used to produce semi synthetic penicillin from natural penicillin. (some penicillin resistant bacteria are not resistant to semi synthetic penicillin)

Question 47

immobilised enzyme definition

Answer 47

enzymes which are isolated from microorganisms, they are attached to an inert insoluble substance and the substrate is passed over it and the reaction takes place.

Question 48

Advantages of using yeast to produce ethanol

Answer 48

-waste products can be used as substrate
- does not use up oil reserves fossil fuels
- carbon neutral process
- requires less energy
Does not need high pressures or high temperatures

Question 49

Disadvantages of using yeast to produce ethanol

Answer 49

Product needs to be purified
Time consuming
Requires aseptic conditions
Only produced via batch method

Question 50

The differences between taking plant cuttings and micropagation

Answer 50

Micropropagation is more expensive requires more equipment
Micropropagation produced more clones
Micropropagation is more time consuming.

Question 51

Advantages of immobilised enzymes

Answer 51

No downstream processing
Less heat sensitive as they are attached to surfaces