Genetic Engineering & GMO'S (1.7)

what is the organism that receives a new gene called (2)

genetically modified OR transgenic organism

what are the two things the process of genetic engineering does?

1.) gives organisms new traits (eg. pest resistant crops)

2.) replaces faulty/missing genes that cause disorder, ensuring the correct proteins is made

explain the process of genetic engineering (4)

1.) a useful gene is identified in a healthy cell and cut out of the DNA

2.) the gene is inserted into the target cell using a vector

3.) the gene becomes integrated into the organism’s genome

4.) the cell now produces the correct protein, and the desired trait is expressed in the phenotype

what are two examples of common vectors used

plasmid or virus

what is the result of genetic engineering? (2)

creates a new DNA sequence in the recipient cell called recombinant DNA that can now produce protein coded for by the new gene and GMO’S

what is the goal of GMO’s?

to improve quality of life and productivity

what are three examples of GMO’S?

microbes, plants, or animals

what are GMO’s used and important in? (4)

• producing medicinal drugs (eg. insulin from bacteria)

• developing new crop varieties with useful traits

• stem cell research

• cloning

explain the six steps of insulin production

1.) the insulin gene is cut from human DNA using restriction enzymes

2.) plasmids are removed from E. coli and cut open with restriction enzymes

3.) the insulin gene is inserted into the plasmid, DNA ligase seals it, forms recombinant DNA.

4.) the recombinant plasmid is placed into the host E. coli cell (transformation)

5.) the bacteria multiply rapidly and produce human insulin

6.) large amounts of insulin are extracted and purified for medical use

what are plasmids?

small circular DNA found in bacteria that carry extra genes

what are restriction enzymes?

an enzyme isolated from bacteria that cuts DNA molecules at specific sequences

what is transformation?

genetic engineering technique where DNA is introduced into cells, allowing them to produce new proteins

what’s used to to create viral antigens?

some bacteria and plants that are genetically modified

what are viral antigens?

a toxin or other substance given off by a virus which causes an immune response in its host

how are antigens used in vaccines?

they trigger an immune response where the body recognizes the antigens as foreign and produces antibodies which provide immunity against future infections

how do GM crops work?

genes for desirable traits are identified and isolated then inserted into plant cells which grow into adult plants with the new trait

what are the two way genes can be transferred?

1.) Gene gun: tiny metal pellets coated with DNA that are shot into plant cells

2.) Bacterial vector: a soil bacterium transfers recombinant plasmids into plant tissue

name five disadvantages of GM crops

1.) some GMO’s may cause allergies in humans

2.) biodiversity decreases when natural habitats are cleared for GM crops

3.) unintended effects can occur, which are unpredictable and uncontrolled

4.) modified seeds can be very expensive

5.) biotechnology costs are high due to the specialized equipment required

Why do bacteria naturally have restriction enzymes?

they evolved as a defence mechanism to cut up viral DNA entering the bacterial cell

What is DNA ligase?

DNA ligase is an enzyme that joins DNA fragments together by forming phosphodiester bonds between nucleotides

How is a gene inserted into DNA using enzymes?

the target gene and plasmid are cut using the same restriction enzyme to create complementary sticky ends, and DNA ligase joins the gene into the plasmid

How is this related to mutations?

artificial genetic modification mimics mutation by changing DNA sequences, but it is directed and controlled rather than random

Why are plasmids useful in genetic engineering?

They act as vectors that carry foreign genes into bacterial cells.

Why are bacteria suitable for hormone production?

They reproduce rapidly, are cheap to culture, and can express foreign genes reliably.

Give two medical uses of plasmids.

Production of insulin and growth hormone.

What is the aim of gene therapy?

To correct the underlying genetic cause of disease rather than just treating symptoms.

What is a vector in gene therapy?

A vector is a carrier used to deliver a therapeutic gene into target cells.

Why are viruses used as vectors?

Viruses naturally inject their genetic material into host cells.

What are bacterial vectors?

Genetically modified bacteria that deliver genes into host tissues.

Difference between somatic and germline gene therapy?

Somatic affects body cells only; germline affects gametes and can be inherited.

: What is plant tissue culture?

A technique where plant cells or tissues are grown in sterile nutrient media to produce clones.

Define cloning in plants.

The production of genetically identical plants from a single parent.

Steps in plant tissue culture.

Explant removed → sterilised → placed in growth medium → cell division → plantlets → transferred to soil.

What is polyploidy?

The condition of having more than two sets of chromosomes.

Why is polyploidy useful in plants?

It increases size, vigour and sometimes fertility or disease resistance.

Positive and negative impacts of GM crops

Positive: higher yield, pest resistance, food security
Negative: reduced biodiversity, dependency on corporations

What is genetic counselling?

A process where individuals receive advice about inherited disorders and their probability of transmission.

Who benefits from genetic counselling?

Carriers of genetic diseases and families with inherited conditions.

How does genetic knowledge affect marriage and child-bearing?

It influences reproductive choices such as IVF, adoption or prenatal screening.

Ethical issue of genetic counselling?

Risk of discrimination or pressure to avoid reproduction.

What is Indigenous Knowledge in agriculture?

Traditional methods such as selective breeding and seed saving.

Argument that genetic engineering is modern.

Uses molecular tools unavailable historically.

Argument that it is based on Indigenous Knowledge.

Builds upon selective breeding and domestication.

Phases of drug trials.

Phase I safety, Phase II effectiveness, Phase III comparison, Phase IV monitoring.

Why do most drugs fail trials? (3)

Toxicity, inefficacy or unexpected side effects.

Ethical requirement of trials?

Informed consent.

Effect of GMOs on traditional farming?

Displacement of indigenous seed systems.

What is monoculture?

: Farming a single crop species over large areas.

Why is monoculture risky?

Increases vulnerability to disease and pests.

Human rights issues in GMOs. (3)

Labelling, consumer choice, biosecurity.

What is CRISPR?

A genome editing system allowing precise modification of DNA.

How does CRISPR work?

Guide RNA directs Cas9 enzyme to cut a specific DNA sequence.

Uses of CRISPR. (3)

Gene therapy, parasite control, crop modification.

What is cloning?

Production of genetically identical organisms.

What is SCNT?

Somatic cell nuclear transfer.

Define donor.

Organism providing the somatic cell nucleus.

Define surrogate.

Organism that carries the embryo.

: Define embryo.

Early stage of development after fertilisation or nuclear transfer.

Compare plant and animal cloning

Plants clone easily; animals require complex laboratory methods.

What is artificial selection?

Deliberate breeding of organisms with desired traits.

Difference between artificial and natural selection?

Artificial is human-directed; natural is environment-driven.

What is hybrid vigour?

Increased performance of cross-bred offspring.

Why does hybrid vigour occur?

Masking of harmful recessive alleles.

Risk of artificial selection?

: Reduced genetic diversity.