biotechnology

Question 1

Describe how to clone a plant by taking a cutting.

Answer 1

use a healthy shoot / cut
shoot from healthy plant ✓
2 cut (stem) at a slant ✓
3 between nodes ✓
4 (dip in) rooting powder /
plant hormone / auxin ✓
5 place in, soil / compost,
and add water ✓

Question 2

Identify three advantages of vegetative propagation in agriculture.

Answer 2

some crop plants cannot
reproduce, sexually / from
seed ✓
2 young seedlings, less likely
to survive / AW ✓
3
quicker than, growing from
seed / sexual reproduction
✓
4
uniform / predictable,
shape / size / quality / yield
✓
5 idea of easier to harvest ✓
6
(propagation) can be done,
at any season / time of year

1 ALLOW seedless / hard to germinate,
plants can be grown
4 ALLOW always get a good yield
4 IGNORE many copies

Question 3

17(a). Tissue culture greatly increases the number of cloned plants that can be produced from a single
parent plant.
Outline how it is possible to produce many clones from a single original parent plant.

Answer 3

many / AW, explants taken
from , original / parent , plant ✓
calluses subdivided ✓
(meristems from) plantlets can
be subdivided

Question 4

What is biotechnology?

Answer 4

Biotechnology is the industrial use of living organisms, or parts of living organisms, to produce food, drugs or other products.

Question 5

What is natural cloning in plants?

Answer 5

Natural cloning in plants is a form of asexual reproduction where the offspring is genetically identical to the parent.

Question 6

What is vegetative propagation?

Answer 6

Vegetative propagation is an example of plant natural cloning where a plant body part is separated and develops into a new plant.

Question 7

How can the English Elm be propagated?

Answer 7

The English Elm can be propagated by removing suckers from the tree during autumn and subsequently growing them in a nursery bed.

Question 8

What are plant cuttings?

Answer 8

Plant cuttings are a simple cloning technique where a section of the stem is cut and encouraged to grow with plant hormones.

Question 9

What is an example of natural cloning in animals?

Answer 9

An example of natural cloning in animals is the formation of twins by embryo splitting.

Question 10

What is tissue culture?

Answer 10

Tissue culture is an example of artificial plant cloning where an explant is taken from the shoot tip and placed on a nutrient-rich growth medium.

Question 11

What happens during tissue culture?

Answer 11

In tissue culture, cells divide by mitosis to form a callus, which can then be stimulated to grow into shoots.

Question 12

What is micropropagation?

Answer 12

Micropropagation is an artificial plant cloning method where a callus is produced and then transferred to a medium with growth regulators.

Question 13

What are the advantages of artificial plant cloning?

Answer 13

Advantages include the ability to produce a large number of plants easily and independently of season or weather.

Question 14

What are the disadvantages of artificial plant cloning?

Answer 14

Disadvantages include lack of variation and difficulty in growing plants compared to sowing seeds.

Question 15

What is nuclear transfer in animal cloning?

Answer 15

Nuclear transfer is a method where a differentiated cell is fused with an enucleated egg cell to produce genetically identical offspring.

Question 16

What is embryo splitting in animal cloning?

Answer 16

Embryo splitting is a method where cells from a developing embryo are separated to produce two genetically identical organisms.

Question 17

What are the advantages of artificial animal cloning?

Answer 17

Advantages include quick cloning of beneficial animals and preservation of endangered species.

Question 18

What are the disadvantages of artificial animal cloning?

Answer 18

Disadvantages include lack of genetic variation and concerns about the health and welfare of cloned animals.

Question 19

Why are microorganisms used in biotechnology?

Answer 19

Microorganisms are easy to grow, can be genetically engineered, and are used in various processes such as brewing and insulin production.

Question 20

What is a pure culture?

Answer 20

A pure culture initially contains only a single microorganism.

Question 21

What is a mixed culture?

Answer 21

A mixed culture is a combination of different species of microorganisms.

Question 22

What is the lag phase in microorganism growth?

Answer 22

The lag phase is when microorganisms adjust to the environment before starting to reproduce, resulting in a constant population.

Question 23

What occurs during the log phase of microorganism growth?

Answer 23

During the log phase, the population size grows exponentially as long as there are sufficient nutrients.

Question 24

What happens in the stationary phase of microorganism growth?

Answer 24

In the stationary phase, the population size reaches its maximum due to decreasing nutrient levels and toxic substance buildup.

Question 25

What is the decline phase in microorganism growth?

Answer 25

The decline phase occurs when lack of nutrients and increased toxic products cause the death of organisms.

Question 26

What is batch culture?

Answer 26

Batch culture is a fermentation process carried out in a closed fermenter where microorganisms and nutrients are added and left to grow for a set time.

Question 27

What is continuous culture?

Answer 27

Continuous culture takes place in an open fermenter where nutrients are continuously added and products are removed at a steady rate.

Question 28

What are the conditions needed to maximize product yield in microorganism culture?

Answer 28

Conditions include maintaining optimum temperature, sufficient nutrient supply, aerobic conditions, and constant pH.

Question 29

What is aseptic condition in microorganism culture?

Answer 29

Aseptic conditions are where unwanted organisms are absent to prevent contamination that can reduce product yield.

Question 30

What are the methods of enzyme immobilisation?

Answer 30

Methods include adsorption, covalent bonding, entrapment, and membrane separation.

Question 31

What is an example of an immobilised enzyme?

Answer 31

Examples include glucose isomerase for converting glucose to fructose and lactase for hydrolyzing lactose.

Question 32

What are the advantages of using immobilised enzymes?

Answer 32

Advantages include preventing product contamination with enzymes and increased stability against temperature changes.

Question 33

what are the main adcantages of using microorganisms in biotechnological processes

Answer 33

1 Points can include: no welfare issues (1); big range of microorganisms available to suit different reactions (1); can genetically manipulate microorganisms to carry out required synthesis reactions e.g., human proteins (1); microorganisms have a very short life-cycle and rapid growth rate so can produce large manufacturing volumes in short time space (1); nutrient requirements of microorganisms often relatively cheap (1); can be genetically manipulated some microorganisms can be modified to utilise materials which would otherwise be wasted (1); microorganisms produce own enzymes so catalyse the reactions (1); processes using microorganisms use relatively low temperatures and pressures (1). Any other sensible points, max 6.

Question 34

cheese making vs yogurt making

Answer 34

c Cheese whole milk used (1); bacteria used to separate the curds from the whey (1); changing texture, and bacteria ripen or mature the cheese in controlled slow reactions at low temperatures to change taste (1); out-compete bacteria that would make the cheese go bad (1); takes weeks, months or years (1); can last for years (1). Yoghurt skimmed milk powder added to milk to enrich it (1); specific bacteria added and incubated at 45°C for 4–5 hours to produce extracellular polymers that give the texture to yoghurt (1); lasts 2–3 weeks in a fridge (1) (1 mark per difference, 2 marks max).

Question 35

why is milk paserised

Answer 35

To destroy bacteria that would make it go bad rapidly (1); or cause diseases such as TB (1)

Question 36

why is milk homogenised

Answer 36

The fat droplets are spread evenly through milk so cream doesn’t separate out (1); and creates a uniform product (1).

Question 37

what is bioremedeation and why is it carried out on site

Answer 37

Use of microorganisms or plants to break down pollutants and contaminants in soil or water (1); often carried out on site (1); because area of contamination may be very large so not practical to remove contaminated material/too expensive to remove contaminated material (1); organisms involved in bioremediation grown and break down contaminants in situ (1); living organisms so they grow and spread (1); may be harvested and contaminants retrieved (1). Any other sensible points.

Question 38

outline the differneces between reproductive and theraputic cloning

Answer 38

Reproductive cloning fertilised egg placed into surrogate; cloned animal allowed to develop; therapeutic cloning fertilised eggs / embryos, remain in lab; e.g. stem cells collected;

Question 39

Describe what is meant by somatic cell nuclear transfer

Answer 39

Nucleus removed from adult (somatic cell); nucleus removed from egg cell of different animal; nucleus from somatic cell placed into (enucleated) egg cell; electric shock to stimulate division; embryo placed into surrogate;

Question 40

define explant and callus

Answer 40

Explant tissue removed, from, plant / animal; transferred to nutrient medium as starting culture; callus undifferentiated, mass of cells; idea of large number of cells that can be split into many cultures;

Question 41

outline the differnces between using graticle counting and dilution plating to count bacteria and state name of a simpler technique

Answer 41

Graticule total count; bacteria not necessarily alive; dilution plating viable count; only live bacteria can form visible colonies; Colorimetry

Question 42

Compare the equipment and techniques of taking cuttings with those used for micropropagation.

Answer 42

cutting needs less / micropropagation needs more, (expensive) equipment (1) cutting needs less / micropropagation needs more, (expensive) skills / staff / AW (1) cutting produces less / micropropagation produces more, clone offspring (1)