Cloning And Biotechnology

Question 1

Define natural plant cloning

Answer 1

Clones are cells or individuals that are genetically identical. Plants naturally produce clones with vegetative propagation using non- reproductive organs

Question 2

A strawberry plant is formed as a genetic clone of the original. State the name of this type of reproduction and describe 2 benefits to the species

Answer 2

Asexual reproduction. Advantageous because, if the conditions are good for the parent plant, condition will also be good for the offspring. Reproduction is very fast, population can increase quickly which is an excellent competitive advantage

Question 3

State the type of cell division that produces clones

Answer 3

Mitosis

Question 4

Define micro propagation

Answer 4

Large scale production of clones from explants,which are cuttings containing meristems cell. Growth hormones are often applied.

Question 5

State 2 tissues or organs that can be used as plant cuttings in horticulture and describe what else is needed to encourage their growth

Answer 5

Root cuttings to plant in new soil

Applying plant hormone to cutting encourages growth of new plant

Question 6

Describe the process of micro propagation

Answer 6

Explant is taken from the plant in sterile condition, from the apical meristems, usually virus free. Sample is then sterilised using ethanol to kill any bacteria or fungi present. Sterilised sample is grown on a growth medium such as agar with nutrients and hormones like auxin. Cell undergo mitosis to form a callus of undifferentiated cells. Tiny plantlets form, transferred to compst/soil to grow.

Question 7

What is the advantages and disadvantages of artificial plant cloning

Answer 7

ADV- cloning can produce large yields of identical planes with desirable traits and allows uniform growth patterns
DIS- clones are susceptible to the same diseases, labour intensive

Question 8

Describe how clones are formed naturally in vertebrates

Answer 8

Clones are formed when a zygote splits to form 2 separate cells

Question 9

Explain the Process of embryo splitting

Answer 9

1) embryo is made from IVF
2) Ball of dividing cells is split
3) Each cell cam form a clone of the embryo

Question 10

Explain the process of SCNT

Answer 10

1) somatic cell nucleus is obtained
2) egg cell nucleus is removed (enucleated)
3) fusion via electric shock
4) cell grows into embryo in surrogate

Question 11

State 2 arguments for artificial cloning in animals and one against

Answer 11

Provides genetically identical organisms for scientific research.
Produce genetically identical coples of high - value individuals
Cloned animals may be less healthy and have shorter life spans

Question 12

Define Microbes in biotechnology -

Answer 12

Microorganisms are preferable to use in biotechnology compared to other organism to other organisms due to number of reasons.
Cheap, low temperature, normal pressures, short life cycle

Question 13

Describe the advantages of using microorganisms to produce drugs

Answer 13

Microorganisms are cheap/easy to grow. Reactions can take place at a lower temperature and pressure as they are catalysed by enzymes, which saves energy. Often, microorganisms can be fed on by - products from the food industry, which keeps cost low. Microorganisms are often easy to separate from the products

Question 14

Explain why lactic acid is formed during fermentation and why it is usually transformation of milk into cheese

Answer 14

Conversion of lactose to lactic acid occurs due to the metabolism of the added bacteria. Lactose decreases, lactic acid increases in concentration in the substrate. Acidity denatures the milk protein, causing it to coagulate

Question 15

Suggest 2 reasons why the public are fearful of the idea of bacterially produced milk

Answer 15

They may not know OR have thought about the role of bacteria in cheese production
Specially worried about using GM bacteria in food production rather than non GM bacteria

Question 16

Define a fermenter

Answer 16

Containers that optimise the conditions for growth of microbes in large scale drug productin

Question 17

Explain why it is necessary to have an outer shell of cooling water in fermenters

Answer 17

Mould that produces penicillin is sensitive to temperature. Water cooler exist to maintain optimal temperature for enzyme function and to ensure the enzymes do not denature

Question 18

Suggest the function and reason behind the pump of hot steam in steam inlet

Answer 18

Sterilise the fermenter before use allowing it to take place in aseptic conditions
Important as the environment in fermenter make a perfect medium for the growth of other microorganisms that could contaminate the product

Question 19

Define continuous culture

Answer 19

Continuous cultures regularly replace nutrients and remove waste products keeping microbes at a constant growth rate

Question 20

Define batch culture

Answer 20

Batch cultures grow organisms until they reach times of stress or overpopulation and product is harvested at the end

Question 21

What is primary and secondary metabolites

Answer 21

Primary - metabolites are harvested produced as part of the normal cell cycle
Secondary - metabolites produced when cells are under stress or the population is too large

Question 22

Explain the difference between batch and continuous culture

Answer 22

Continuous culture, sterile nutrient medium is continuously added, whereas in batch culture there is a fixed quantity of the medium. Continuous culture, products and waste are continually removed, batch culture removed at the end of each fermentation.
Batch culture, fermenter is sterilised between each fermentation which is not necessary for continuous culture

Question 23

Explain how bacteria can be introduced to a Petri dish containing agar with an aseptic technique

Answer 23

Equipment used to introduce the bacteria can be sterilised over a Bunsen flame to kill unwanted organisms
Petri dish only needs to be slightly opened for the instrument to prevent other bacteria in the air entering it
Bacteria introduced in inoculation using a spreading technique with a glass spreader

Question 24

Explain how a serial dilution can be formed for a bacterial broth solution

Answer 24

Take 1ml of broth solution from the original container and place into a test tube. Add 9ml of distilled water to the test tube p, 1:10 dilution.

Question 25

Explain why broth containing high concentration of bacteria cannot be directly added to agar jelly experiment

Answer 25

Concentration of bacterial cells in the broth very high, means colonies that grow on the agar will likely merge together and be difficult to count.
Creating serial dilution ensures the concentration is reduced and colonies will be discrete and countable

Question 26

Explain the bacterial growth curve

Answer 26

Lag phase - bacteria adjusting to the environment by expressing genes and taking up water
Log phase - bacteria have sufficient nutrients and space to grow and reproduce
Stationary phase - rate of bacteria being made = the rate of those dying
Death phase - more organism are dying then produced

Question 27

Describe why bacterial cell population increase is represented by logarithmic scale

Answer 27

Short period of time, large increase in the bacterial cell population by several orders of magnitude. Growing exponentially. Logarithmic graphs are used to represent large ranges in numbers

Question 28

Suggest why many bacterial cells die during the death phase of the growth curve

Answer 28

Decrease in the amount of agar (food substrate) available, limiting factor due to intraspecfic competition

Question 29

Explain enzyme immobilised by covalent bonding

Answer 29

Covalently binding enzyme to a solid surface

Question 30

Explain 2 limitations of enzyme immobilisation by adsorption

Answer 30

active site of the enzyme may be slightly distorted due to the interactions the enzyme has with the supporting surface. Distortion of active site can reduce enzyme activity, meaning less substrate is converted to product.
Enzymes can easily detach from supporting surfaces and mix with the solution

Question 31

What are perennating organs and how are they involved in cloning and survival

Answer 31

Organ which contains stored food from photosynthesis e.g potato
Allows plants to survive adverse conditions and produce a new shoot

Question 32

Explain the advantages and disadvantages of propagating crop plant by cuttings over using seeds

Answer 32

Cuttings - genetically identical to parent so likely to produce good crops, often shorter time from planting to crop, reliable, can use own plants
Seeds - have genetic variation so more variability in quality of crop, more likely to withstand disease of changes in circumstances

Question 33

Suggest why it is important to describe clones as genetically identical to their parent rathe than simply identical

Answer 33

Genetically identical because parts of the same plant, but eventually will depend on growing conditions

Question 34

What are the main advantage of micro propagation of crop plants

Answer 34

Reliable way of increasing numbers of endangered plants which will help towards maintaining biodiversity of ecosystems
Allows for rapid production of large number of crops which is valuable for countries where there are food shortages

Question 35

Explain why plants are more able to form natural reproductive clones than animals

Answer 35

most plant cells retain ability to differentiate because it is totipotent
plant have meristems
can differentiate into different cell type

Question 36

Evaluate the use of immobilised enzymes

Answer 36

+ product is not contaminated by enzymes do does not need to be purified
+ enzymes can be re used
+ enzymes are protected from harsh environment
- reaction rate is slower as enzymes cannot move

Question 37

Give use of immobilised enzymes

Answer 37

Glucose to fructose conversion
Semi synthetic penicillin production
Lactose to glucose/galactose conversion

Question 38

Give methods of immobilising enzymes

Answer 38

Bonding - enzymes binds with support ionically(adsorption) or covalently
Entrapment - enzyme placed in a semi permeable material that allows diffusion of the substrate and product
Membrane separation- partially permeable membrane separates enzyme from substrate

Question 39

Differentiate between batch and continuous fermentation

Answer 39

Batch = closed environment, competition for resources, less efficient, easy to set up
Continuous - products continually removed, maintains culture in log phase,difficult to set up, more efficient

Question 40

Define both primary and secondary metabolites

Answer 40

Metabolite - intermediates and products of metabolism
Primary metabolite - directly involved in normal growth,development and reproduction
Secondary - not directly involved in the process, important ecological function,e.g antibiotics and pigments

Question 41

Identify aseptic techniques

Answer 41

Ensuring all fermenters and attachments are sterile before microorganisms or substrate added
Sterilising all liquid ,solids and gas enter
Ensuring workers do not introduce unwanted microorganisms
Steady airflow

Question 42

Define the process of brewing

Answer 42

Yeast respires anaerobically to produce ethanol