Cloning and biotechnology -

Question 1

Natural plant cloning is exploited by?

Answer 1

Horticulture in farmers. Produce young plants and the new plants have exactly the same genetic characteristics as their parents. Also possible to take many cuttings of plants of short sections of stems and planted directly into the ground.

Question 2

Vegetative propagation -

Answer 2

Perennating organs, which enables plants to survive adverse conditions. Often a means of asexual reproduction and there a few examples.

Question 3

Vegetative propagation examples -

Answer 3

Runners - Lateral stem grows away from the parent plant and roots develop where the runners touch the ground, new plant develops.
Rhizomes - Specialised horizontal stem running underground, buds develop from it and become independent plants.
Stem tubers - Tip of an underground stem becomes swollen with stored food to form a tuber or storage organ like a potato.

Question 4

Micropropagation is artificial cloning of plants -

Answer 4

• Makes large numbers of genetically identical offspring from a single parent plant, useful when they don’t produce seeds, rare and doesn’t respond well to natural cloning.

Question 5

Basic principles of micropropagation -

Answer 5

1. Small sample of tissue is taken from meristem tissue with totipotent cells. (called an explant)
2. The sample is sterilised to reduce contamination (bleach)
3. The explant is placed in a sterile culture containing plant hormones (auxins), stimulate mitosis. Makes a mass of cells called callus.
4. The callus is then divided up and place in a culture medium containing different mixes of hormones and nutrients
5. They then form plantlets and are potted into compost and then are planted out to grow into small plants.

Question 6

Advantages of micropropagation -

Answer 6

• Produce good crop yield of one individual plant
• Useful for seeds that are difficult to grow
• Allows plants to grow any kind of year.

Question 7

Disadvantages of micropropagation -

Answer 7

• Monoculture meaning the genetically identical plants can be killed off by one disease
• Expensive and requires skill

Question 8

Natural cloning is more common in invertebrates compared to vertebrates like a starfish -

Answer 8

Can regenerate entire animals from fragments of the original if damaged.

Question 9

Cloning in vertebrate of humans is seen most common in monozygotic twins -

Answer 9

Formation:
Early embryo splits to form a separate embryo or even multiple times for triplets it it still deeply misunderstood for how it happens and its causes.

Question 10

Artificial cloning in animals can be done two ways in highly farmed animals of vertebrates -

Answer 10

Artificial twinning and somatic cell nuclear transfer.

Question 11

Artificial twinning basic points -

Answer 11

After an egg is fertilised, it divides to form a ball of cells which are totipotent (form a whole new animal), the split in the early embryo is done manually and may be split more than twice. Done in the farming community to maximise offspring with desirable characteristics.

Question 12

Summarised stages of artificial twinning -

Answer 12

• Early embryo from the cow with desirable characteristics, the embryo from ovulation happens early through hormones
• Where the mature eggs are removed they are fertilised by top-quality bull semen
• After when the cells are totipotent the cells of the embryo are split to produce smaller embryos where they are grown in the lab
• Planted in the surrogate mother
• The embryos develop into foetuses and develop naturally, so a number of identical clones are produced from mothers.
• Where the embryos have 100% genetic identity as the embryo developed from with the desirable trait.

Question 13

Somatic cell nuclear transfer -

Answer 13

SCNT is different as it isn’t involved of the embryo, by taking the nucleus of a somatic body cell and transferring it to an enucleated egg cell with a tiny electric shock to fuse them together, stimulating the combined cell to divide and form an embryo.

Question 14

Stages of SCNT -

Answer 14

1. Nucleus is removed from the somatic cell of an adult animal
2. Nucleus is also removed from a mature ovum harvested from a different female animal (enucleated)
3. The somatic nucleus is placed into the enucleated ovum and given a mild electric shock so it fuses and begins to divide
4. The embryo that develops from this is transferred into the uterus of a third animal.
5. The animal is derived from the original somatic cell but the mitochondrial DNA comes from the egg cell.

Question 15

Arguments for cloning of animals -

Answer 15

• Higher yield of offspring than normal reproduction (AT)
• SCNT has the potential to enable rare or even extinct species of animals to be reproduced
• SCNT allows the meetings of higher yield and allow products and goods to be used at a much sustainable rate.

Question 16

Arguments against animal cloning -

Answer 16

SCNT is very inefficient and takes many animal eggs to a single cloned offspring
Many cloned offspring have shortened lifespans
SCNT has also been unsuccessful in increasing population of rare organisms.

Question 17

Biotechnology definition -

Answer 17

Involves applying biological organisms or enzymes to the synthesis/breakdown or transformation of material in the service of people.

Question 18

The use of microorganisms in biotechnology -

Answer 18

• Mainly use biological catalysts in a manufacturing process
• Microorganisms have a very short life cycle and rapid growth rate. As a result, given the conditions of food, oxygen and temperature are right large quantities can be produced in short periods.
• Nutrient requirements of microorganisms are relatively simple and therefore cheap, genetic manipulation can be useful so we can modify materials that would indeed be wasted.

Question 19

Indirect food production -

Answer 19

Microorganisms have an indirect effect on food, its there actions on the food that is important.

Question 20

Indirect food use of microorganisms such as yeast (fungus) -

Answer 20

Baking and brewing where yeast respires aerobically and anaerobically

Question 21

Microorganisms and the use of bacteria in?

Answer 21

cheese making and yoghurt.

Question 22

Direct food production -

Answer 22

Best known is fungus in a wide variety of mushrooms directed by microorganisms. Also a big wide introduce is Quorn and is made of fungus and is grown in large fermenters and made into meat substitutes.

Question 23

Bioremediation -

Answer 23

Microorganisms are used to break down pollutants and contaminants in the soil or water.
Can use natural organisms or GM organisms, can take place on the site of contamination useful in neutralising many contaminants.

Question 24

Culturing microorganisms -

Answer 24

Need food, temperature, oxygen and pH, best known as nutrient medium, can be as liquid broth or solid as agar

Question 25

Broth inoculating -

Answer 25

Suspension of broth to be grown, mix with a volume of sterile nutrients in the flask. Incubate a stable temperature.

Question 26

Inoculating agar -

Answer 26

The wire inoculating group must be sterilised holding it in the Bunsen burner , not touch any surfaces to avoid contamination.

Question 27

Isolated enzymes advantages of use -

Answer 27

Less wasteful - whole microorganisms use up substrate growth whilst isolated enzymes do not.
More efficient - isolated enzymes work at much higher concentrations than is possible when they are part of the whole microorganism.
Specific reactions result in no wasteful side reactions to take place.

Question 28

Most isolated enzymes are extracellular and have many benefits -

Answer 28

Extracellular enzymes are secreted meaning they are easier to use.
Extracellular enzymes are adapted to deal with such conditions outside the cell so they can deal with temperature change and when pH varies.

Question 29

Immobilised enzymes -

Answer 29

Increasingly enzymes used in industrial practices are immobilised and are attached to an inert support system over which the substrate passes and is converted into product.

Question 30

Advantages of immobilised enzymes -

Answer 30

Can be reused which is cheaper and are easily separated from the reactants and products of the reaction. Ease of manipulation - the catalytic properties of immobilised enzymes can be fit to a particular process more easily than free enzymes such as glucose isomerase.

Question 31

Disadvantages of immobilised enzymes -

Answer 31

Reduced efficiency - immobilising an enzyme may reduce its reactivity rate.
Genuinely more expensive than free enzymes of microorganisms, however they don’t need to be replaced as often.

Question 32

How do enzymes become immobilised?

Answer 32

Surface immobilisation - adsorption to inorganic carriers or covalent or ionic bonding to inorganic carriers
Entrapment - in the matrix/membrane entrapment in microcapsules (encapsulation)

Question 33

Using immobilised enzymes -

Answer 33

Immobilised lactase used to produce lactose-free milk, immobilised enzymes lactase hydrolyses lactose to glucose and galactose giving lactose free milk.
Immobilised glucose isomerase - used to produce fructose from glucose, glucose is produced cheap, glucose isomerase then turns to cheap glucose into very marketable fructose.

Question 34

Controlling Bioreactors -

Answer 34

Temperature should not be too low or high due to microorganisms and enzymes denaturing.
Oxygen and nutrients can be added in controlled amounts to the broth, when probes or sample tests indicate the levels are dropping.
Asepsis - if the process is contaminated by microorganisms from the air, it can affect yield, to solve this most bioreactors are sealed, if they are genetically engineered organisms in there, then it is a legal requirement.