6.2.1: Cloning and biotechnology

Question 1

How can we produce natural clones of plants?

Answer 1

Vegetative propagation. Part of a plant is
separated, then develops into a new plant
genetically identical to the original. English
Elm does not produce viable seed, 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.
Replanted and allowed to grow,
sometimes with the use of plant
hormones.

Question 3

How can we produce artificial clones of plants?

Answer 3

● Tissue culture; sample placed on various
nutrient-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 animals.

Answer 5

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

Question 6

How can we produce artificial clones of 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

biotechnological 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
  animal 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; microorganism 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 the growth conditions manipulated to

maximise yield?

Answer 15

● Temperature maintained at optimum.
● Sufficient nutrient supply.
● Aerobic conditions to prevent products 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 in water. Population
constant.
● Log= cells divide. Population increases exponentially.
● Stationary= nutrient levels decrease, slowing growth
rate. Population stabilizes.
● Death= toxic metabolites increase to a point that kills
cells. Population declines.

Question 17

Give the formula for bacterial growth.

Answer 17

N = N0 x 2n
● N = number of bacteria currently in the
population
● N0 = number of bacteria in the population at
the beginning
● n = number of divisions

Question 18

What is an immobilised enzyme?

Answer 18

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

Question 19

Give methods of immobilising enzymes.

Answer 19

1. Bonding= enzyme binds with support ionically
   (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 enzyme from substrate.

Question 20

Give uses of immobilised enzymes.

Answer 20

● Glucose to fructose conversion.
● Semi-synthetic penicillin production.
● Lactose to glucose/galactose conversion.
● Pure samples of amino acids.
● Dextrins to glucose conversion.

Question 21

Evaluate the use of immobilised enzymes.

Answer 21

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