Cloning and Biotechnology

Question 1

How can we produce natural clones of plants ?

Answer 1

Vegetative propagation. Part of the plant is separated, which then develops into a new plant genetically identical to the original. For Example - English Elm does not produce viable seeds, so naturally self-propagates using its roots

Question 2

How should a plant cutting be taken for cloning ?

Answer 2

Stem is cut between the leaf and nodes. It is dipped in rooting hormones, stimulating the growth. The plant is then replanted in solid

Question 3

How can we produce artificial clones of plants ?

Answer 3

• Tissue culture; sample paced on various nutrients-containing mediums to encourage cell division and shoot growth
• Micropropagation; material produced from tissue culture is rapidly multiplied to produce large numbers of plants

Question 4

Evaluate the use of artificial plant cloning in agriculture

Answer 4

+ Large number of plants can be produced regardless of weather conditions
- Reduces genetic variation, making them susceptible to disease

Question 5

Give an example of natural cloning in Animails

Answer 5

Monozygotic twins; embryo splits during development to produce two genetically identical individuals

Question 6

How can we produce artificial clones in animals ?

Answer 6

• Somatic Cell nuclear transfer; differentiated cell from parent fused with an enucleated egg cell. The cell develops into an embryo and can be implanted into a womb
• Embryo splitting; Same process by which twins form, performed artificially

Question 7

Give arguments surrounding cloning in animals

Answer 7

+ Quick process suited to the growing population of earth
+ Can preserve endangered species
- Cloned animals often suffer from health problems
- Low genetic diversity

Question 8

Why are microorganisms suited for use in biotechnical processes ?

Answer 8

• Rapid growth in a variety of environmental conditions
• Can be genetically engineered
• Reduces use of chemicals, beneficial to the environment

Question 9

Give some ways microorganisms are used in biotechnological processes

Answer 9

• Food; baking, brewing, yogurt, cheese
• Medicine; penicillin, insulin
• Environmental; removing pollution (bioremediation)

Question 10

Give advantages of using microorganisms to produce food for human consumption

Answer 10

+ Production rate easily varied
+ Not dependent on climate
+ Long-Lasting
+ Uses waste products

Question 11

Give disadvantages of using microorganisms to produce food for human consumption

Answer 11

• Lack of flavour
• Proteins must be isolated and purified
• Contains different amino acids to animails proteins

Question 12

Describe the technique that should be used to culture microorganisms

Answer 12

Aseptic technique; everything must be kept completely sterile so that no unwanted microorganisms are present in the culture

Question 13

Summarise the three steps of growing microorganisms

Answer 13

1. Sterilisation; part of the aseptic technique
2. Inoculation; microorganisms introduced to agar plate by streaking, seeding or spreading
3. Incubation: placed in warm environment for 24-48 hours to grow

Question 14

Differentiate between batch and continuous fermentation

Answer 14

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

Question 15

How are growth conditions manipulated to maximise yield ?

Answer 15

• Temperature maintained at optimum
• Sufficient nutrient supply
• Aerobic conditions to prevent product of anaerobic respiration
• pH kept constant to maximise enzyme activity

Question 16

Describe the phases of a growth curve of a microorganism in a closed culture

Answer 16

• Lag = cells increase in size and take water in.Population constant
• Log = cells divide. Population increases exponentially
• Stationary = nutrient levels decrease, slowing growth rate. Population stabilises
• Death = toxic metabolites increase to a point that kills cells. Population declines

Question 17

What is an immobilised enzyme ?

Answer 17

An enzyme attached to an inert material in order to restrict its movement and hold it in palace during a reaction so that it can be reused

Question 18

Give Methods of immobilising enzymes

Answer 18

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

Question 19

Give uses of immobilised enzymes

Answer 19

• Glucose
• Semi-Synthetic penicillin production
• Lactose to glucose/galactose conversion
• Pure samples of amino acids
• Dextrins to glucose conversion

Question 20

Evaluate the use of immobilised enzymes

Answer 20

+ Product is not contaminated by enzymes, so does not need to be purified
+ Enzyme can be reused
+ Enzymes are protected from harsh environment
- Expensive
- Reaction rate is slower as enzymes cannot move