Module 6: Cloning And Biotechnology

Question 1

What is cloning?

Answer 1

Creating a genetically identical copy of an organism or cell.
Produced by asexual reproduction so no gametes are involved.

Question 2

True or False: Cloning can occur naturally.

Answer 2

True

Question 3

Plant cloning

Answer 3

Many plants can reproduce asexually using meristem cells, in a process called vegetative reproduction

Vegetative organs of plants include:
Root and shoot tips
Axillary buds (where leaves and the stem meet)
Vascular cambium (between xylem and phloem)
Naturally, over time a young, miniature plant (a plantlet) forms at these locations and remains attached to its parent plant

These plantlets are clones of their parent (as no other DNA has been introduced)

At maturity, the plantlet becomes detached from its parent and can live independently, when it is capable of photosynthesizing by itself

The new plants all have the same phenotype, so are uniform, making growing and harvesting easier

Plants that are hard to grow from seeds can be propagated, eg. orchids for the horticulture industry

Some plants have horizontal stems or runners that form over the soil surface, pointing sufficiently far away so that a new plant at that location will not be overshadowed by its parent, or in competition for water or soil nutrients

Roots form under the nodes of runners, called adventitious roots

The runner dies when the plantlet is self-sustaining

Strawberries, peppermint and spider plants reproduce in this way

Question 4

Vegetative propagation.

Answer 4

Many methods of propagation do not require seeds as it is not sexual reproduction that is occurring, it is asexual reproduction

A well as runners, plants can propagate asexually using tubers, rhizomes, bulbs, suckers, and offsets

All modes of vegetative propagation contain modified stems that can generate meristematic tissue

Potato tubers are swollen modified roots that form eyes on their surface

Eyes can sprout new growth (called ‘chitting’)

The starch stored in the tuber fuels the early growth of the new plant

Ginger forms rhizomes, a modified stem that grows horizontally underground

New growth stems from nodes in the rhizome, forming new stems and adventitious roots

The section used in cookery is the rhizome

Onions and garlic form bulbs that can grow adventitious roots underground and leafy shoots above ground

Suckers are growths that appear from the root systems of many trees and shrubs, which can provide meristematic tissue for vegetative propagation

Examples are poplars, cherries and plums

Offsets are small, virtually complete daughter plants that have been asexually produced on the mother plant

Examples are tulips and lilies

Gardeners and horticulturalists can use these techniques to propagate desirable species asexually, effectively and at less cost than utilising sexual reproduction techniques

This is done by taking cuttings and dividing up plants into different clumps or sections

Question 5

What is the primary purpose of biotechnology?

Answer 5

The primary purpose of biotechnology is to manipulate living organisms or their components to develop products and technologies.

Question 6

Fill in the blank: The process of creating a genetically identical organism from a somatic cell is called __________ cloning.

Answer 6

somatic cell

Question 7

What is a stem cell?

Answer 7

A stem cell is a unique type of cell that can develop into many different cell types in the body.

Question 8

What technique is commonly used to produce genetically modified organisms (GMOs)?

Answer 8

Recombinant DNA technology

Question 9

What is the main ethical concern associated with cloning?

Answer 9

The main ethical concern is the potential for loss of genetic diversity and the welfare of cloned animals.

Question 10

True or False: All cloned organisms are genetically identical to their donors.

Answer 10

False

Question 11

What is the term for the technique where a nucleus from a somatic cell is inserted into an egg cell?

Answer 11

Nuclear transfer

Question 12

List one application of cloning in agriculture.

Answer 12

Cloning can be used to produce genetically identical plants with desirable traits.

Question 13

What is gene therapy?

Answer 13

Gene therapy is the technique of altering the genes inside an individual’s cells to treat or prevent disease.

Question 14

Fill in the blank: __________ is a method of cloning that involves creating a copy of a DNA sequence.

Answer 14

Polymerase chain reaction (PCR)

Question 15

What is a clone?

Answer 15

A clone is an organism or cell that is genetically identical to another organism or cell.

Question 16

True or False: Cloning is only performed on animals.

Answer 16

False

Question 17

What is the significance of Dolly the sheep in the context of cloning?

Answer 17

Dolly was the first mammal to be cloned from an adult somatic cell, demonstrating that specialized cells could be used to create a clone.

Question 18

What is a transgenic organism?

Answer 18

A transgenic organism is one that has had a foreign gene deliberately inserted into its genome.

Question 19

Fill in the blank: __________ is a technique used to create a population of genetically identical plants from a single parent plant.

Answer 19

Tissue culture

Question 20

True or False: Cloning can be used to produce organs for transplantation.

Answer 20

True

Question 21

What is the role of plasmids in genetic engineering?

Answer 21

Plasmids are used as vectors to transfer genetic material into host cells.

Question 22

What is the term for the process of using living organisms to produce useful products?

Answer 22

Bioprocessing

Question 23

What is somatic cell nuclear transfer (SCNT)?

Answer 23

Cloning technique where the nucleus of a somatic cell (any cell apart from reproductive cell) is transferred to an enucleated (got nucleus removed) egg cell.

Question 24

Fill in the blank: __________ refers to the use of microorganisms to break down pollutants in the environment.

Answer 24

Bioremediation

Question 25

What is one potential benefit of cloning endangered species?

Answer 25

Cloning endangered species may help increase their population and prevent extinction.

Question 26

What is the term for the DNA sequence that is recognized and cut by restriction enzymes?

Answer 26

Restriction site

Question 27

True or False: Cloning can only be performed in a laboratory setting.

Answer 27

False

Question 28

How should a plant cutting be taken for cloning?

Answer 28

Stem is cut between leaf and nodes. Replanted and allowed to grow, sometimes using plant hormones too.

Question 29

How can we produce artificial clones of plants?

Answer 29

1. Tissue culture - sample placed on various nutrient containing mediums to encourage cell division and shoot growth. 2. Micropropagation - material produced from tissue culture is rapidly multiplied to produce a large no. plants.

Question 30

Evaluate the use of artificial cloning in plants.

Answer 30

Large no. plants can be produced regardless of weather conditions. Reduces genetic variation, making them susceptible to disease.

Question 31

Evaluate the use of artificial cloning in plants.

Answer 31

Large no. plants can be produced regardless of weather conditions. Reduces genetic variation, making them susceptible to disease.

Question 32

Example of natural animal cloning?

Answer 32

Monozygotic twins - embryo splits to produce 2 genetically identical individuals.

Question 33

2 ways to produce artificial clones for animals?

Answer 33

1. Somatic cell nuclear transfer - adult somatic cell fuses with enucleated egg cell. This cell develops into an embryo which is inserted back into womb. 2. Embryo splitting - same processes where twins form, but artificially.

Question 34

Describe the technique used to culture organisms.

Answer 34

Aseptic technique - everything must be sterile to prevent unwanted microorganisms in culture.

Question 35

Summarise 3 steps of growing microorganisms.

Answer 35

1. Sterilisation- part of aseptic technique. 2. Inoculation - microorganisms spread in agar by spreading in lines. 3. Intubation - placed in warm environment to grow for 24-48 hours.

Question 36

What is asexual reproduction?

Answer 36

Offspring arise from a single organism so they are genetically identical. Doesn’t involve fusion of gametes.

Question 37

Describe some examples of asexual reproduction.

Answer 37

Binary fission - parent cell simply divides into two like bacteria. Spores - special cells released by the parent become new organisms. Fungi. Fragmentation - severed body parts grown into new organisms. Sea stars.

Question 38

Explain the method to produce natural plant clones.

Answer 38

Vegetative propagation - new plant grows from sections of roots stems or leaves which are cut off from parent.

Question 39

List the advantages of vegetative propagation.

Answer 39

The plants cultivated are genetically identical to their parents. Plants can be cultivated faster as compared to growing them from seeds.

Question 40

Cons of vegetative propagation?

Answer 40

Vegetative propagated plants are short-lived, small compared to seed propagated plants No new varieties can be produced Skilled persons are required and often expensive compared to seed propagation More susceptible to diseases as the entire plant may get affected as there is no genetic variation

Question 41

Pros and cons of sexual and asexual reproduction?

Answer 41

Sexual - high genetic variability, adaptation. Courtship is time/resource consuming. Asexual - saves energy, courtship is non issue. Low genetic variability, adaptation to environment is difficult.

Question 42

Immobilised enzymes

Answer 42

An immobilised enzyme is an enzyme that is attached to an insoluble material to prevent mixing with the product Enzymes can be immobilised in several ways: Attached to an inert substance Enclosed in a capsule Contained within a partially permeable membrane

Question 43

Advantages of immobilised enzymes There is no enzyme in the product (the product is uncontaminated) and therefore there is no need to further process or filter the end product The immobilised enzyme can be reused multiple times which is both efficient and cost-effective (enzymes are expensive) Immobilised enzymes have a greater tolerance of temperature and pH changes (immobilisation often makes enzymes more stable) Disadvantages of immobilised enzymes Specialist expensive equipment is required Immobilised enzymes are more costly to buy, so are unlikely to be financially worthwhile for smaller industries The rate of reaction is sometimes lower when using immobilised enzymes as the enzymes cannot freely mix with the substrate Immobilised enzymes in industry There are many industrial and medical applications of immobilised enzymes, including production of the following: Lactose-free dairy products such as milk Enzyme: Lactase Converts lactose to glucose and galactose Semi-synthetic penicillin which overcomes issues of penicillin resistance Enzyme: Penicillin acylase Converts the original form of penicillin into one which is effective against penicillin-resistant organisms

Answer 43

Enzymes are often immobilised for use in industrial processes as it means the enzyme can be reused in future processes rather than being discarded after it has been used once Reusing the enzyme also avoids the need to separate the enzyme from the product in downstream processing The immobilised enzymes are contained within a column through which the substrate is filtered in solution As the substrate runs through the column, enzyme-substrate complexes are formed and products are produced These products then flow out of the column, leaving the enzymes behind to catalyse the reaction again

Question 44

Production of Artificial Clones in Plants

Answer 44

Micropropagation and tissue culture Many plant cells are totipotent, unlike animal cells, and therefore an entire plant can be reproduced from any of these cells Creating clones of cauliflowers is used to demonstrate totipotency through the production of tissue culture Cauliflower is used because it is comprised mostly of actively dividing cells and can withstand being handled A small piece of the plant is cut, this is called an explant, which is then grown into a new clone of the original plant Care must be taken to disinfect the explant and to use aseptic techniques to avoid fungi from colonising the growth medium and causing the micropropagation to fail This technique is used by scientists to reproduce endangered species of plants where relatively little source material exists

Question 45

METHOD: Micropropagation and tissue culture

Answer 45

Equipment: goggles, disinfectant (usually a bleach solution), scalpel, gloves, forceps, cauliflower, agar growth medium containing sterilant, container, marker pen. Wipe all surfaces with disinfectant and soak all apparatus in sterilant It is important to ensure a sterile environment so that no fungi contaminate the experiment, which would result in seeing a fungal growth rather than an explant growth Break off a small floret of cauliflower from the plant then using a scalpel, cut a thin section of the floret (about 5-10mm long) This thin section is the explant Sterilise the explant by soaking it in sterilising solution for 15 minutes, swirling the explant around within the solution every 5 minutes This ensures that the explant is sterile and therefore only cauliflower cells are present Take out the explant using sterilised forceps and add it to a container of agar growth medium The growth medium contains all the nutrients that the plant needs for growth and also contains a sterilant to ensure no contamination occurs throughout the experiment Leave the container holding the agar growth medium and the explant on a sunny windowsill for 3 weeks

Question 46

Results for this experiment?

Answer 46

The result of this experiment is to grow a complete cauliflower clone from an explant This shows that the cells in the explant have the capability to produce all the different cell types that make up a full cauliflower plant, hence they are totipotent The complete cauliflower plant can then be distributed to commercial growers/garden centres in large numbers

Question 47

Micropropagation via plant tissue culture has several applications

Answer 47

It enables the rapid and large-scale propagation of plants that naturally reproduce slowly or are rare or endangered. It is used for producing disease-free clones of crops and preserving valuable genetic resources. It allows the mass production of genetically modified plants, such as those engineered for herbicide resistance. It can be used to produce seedless plants or those that are difficult to cultivate from

Question 48

micropropagatuon.

Answer 48

Small tissue samples called explants are taken from a parent plant to start the micropropagation process. Explants are typically taken from the stem and root tips as they have meristem cells. Meristem cells are totipotent so can differentiate into any type of plant cell. The explant's cells are sterilised to remove and inhibit the growth of contaminants such as bacteria and fungi. This reduces the risk of widespread infection and helps to produce healthier crops. Culture The sterilised explant cells are then cultured on a nutrient-rich medium. The medium supplies minerals, sugars, vitamins, and growth hormones like auxins that support rapid cell division and growth The cells in each explant divide to form an undifferentiated mass of cells called a callus. The callus cells are transferred to a new medium with specific conditions to encourage shoot and root formation. This allows the callus cells to differentiate and develop into plantlets. Fully formed plantlets, complete with shoots and roots, are moved to a growth medium like soil. There, they can develop into mature plants that are identical to the parent plant.