Form 5 · Common mistakes

Genetic Technology, common mistakes

The mistakes SPM students make on Genetic Technology, why each one loses marks, and the correct version.

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The mistakes, why they lose marks, and the fix

Common mistake	Why it loses marks	What earns the mark
Confusing genetic engineering with selective breeding.	Selective breeding only works with genetic variation that already exists in a population and cannot cross species; genetic engineering directly alters genes in the laboratory and can transfer a gene between very different species.	State that genetic engineering directly changes genes in the laboratory and can cross species, while selective breeding only selects among existing variation.
Saying insulin is made from human pancreas cells.	Human insulin is now commonly made by bacteria that have been given the human insulin gene, not by extracting it directly from a human pancreas.	State that human insulin is produced by bacteria carrying the inserted human insulin gene.
Writing that all genetically modified food is unsafe.	Each genetically modified crop is tested and regulated based on the specific gene it carries and its observed effects, not judged automatically as a single unsafe category.	State that a genetically modified crop's safety depends on the specific inserted gene, so each crop is tested individually.
Treating biotechnology as only genetic engineering.	Biotechnology is a much broader field that includes fermentation, enzyme technology and vaccine production, some of which have been used for centuries before genetic engineering existed.	State that biotechnology includes traditional processes such as fermentation, with genetic engineering as only one modern branch.
Believing gene therapy changes a person's entire genome instantly.	Gene therapy targets a specific faulty gene within particular cells or tissues, so it does not automatically alter every cell in the body or every gene a person carries.	State that gene therapy targets specific cells to correct one faulty gene, not the whole genome.
Saying DNA fingerprinting changes or edits a person's genes.	DNA fingerprinting only reads and compares existing patterns in a person's DNA; no gene is added, removed or altered during the process.	State that DNA fingerprinting compares existing DNA patterns without altering any gene.
Treating reproductive and therapeutic cloning as the same procedure.	Reproductive cloning produces a whole new genetically identical organism, while therapeutic cloning aims only to produce cells or tissue for treatment without creating a new individual.	State that reproductive cloning creates a new organism, while therapeutic cloning creates cells or tissue for treatment.
Assuming a GM crop is automatically dangerous because it is genetically modified.	Safety depends on the specific gene inserted and its observed effects, which is why each genetically modified crop is regulated individually rather than judged as a category.	State that two GM crops carrying different inserted genes can carry very different risk profiles.
Saying a plasmid is a type of chromosome.	A plasmid is a small circular piece of bacterial DNA that exists separately from the bacterium's main chromosome and is used mainly as a vector for a transferred gene.	State that a plasmid is a small circular DNA molecule distinct from the bacterium's main chromosome.
Saying recombinant DNA forms naturally without any laboratory intervention.	Recombinant DNA is formed deliberately by cutting a gene from one source and joining it into DNA from another source using specific enzymes.	State that recombinant DNA is produced deliberately in the laboratory using enzymes to cut and join DNA.
Saying every genetically modified crop carries the same benefits and risks.	Each GM crop carries a different inserted gene for a different purpose, such as pest resistance or herbicide tolerance, so its specific benefits and risks follow from that particular gene.	State that the benefit or risk of a genetically modified crop depends on the specific gene it carries.
Saying DNA fingerprinting can tell identical twins apart as two different people.	Identical twins share an identical genotype from a single fertilised egg, so their DNA fingerprint patterns are the same and cannot be distinguished from one another by this method alone.	State that DNA fingerprinting cannot distinguish identical twins from each other, since their DNA patterns are identical.
Saying a clone is identical to the original organism in every observable way.	A clone shares the same genes as the original, but its observable characteristics can still differ because the environment also plays a part in how those genes are expressed during development.	State that a clone is genetically identical to the original, though its appearance or behaviour may still differ because of environmental effects.
Saying gene therapy is a routine treatment already available for most genetic diseases.	Research in gene therapy remains active, and the number of widely approved treatments stays small compared with conventional medicine, so it currently applies to a limited number of conditions.	State that gene therapy is an emerging treatment approved for only a limited number of conditions.

How to avoid these mistakes

Learn a clear definition and one detailed example of genetic engineering.
Follow the steps of using bacteria to produce insulin, from gene to plasmid to protein.
List one benefit and one concern for genetic technology so you can write a balanced answer.
Learn one example each of gene therapy, DNA fingerprinting and a genetically modified crop.
Compare reproductive and therapeutic cloning in a short table of purpose and outcome.
Practise explaining why a genetically modified organism is tested individually rather than judged as a category.

Frequently asked questions

What is genetic engineering?

Genetic engineering is the deliberate changing of an organism's genes, usually by taking a gene from one organism and inserting it into another so that the second organism gains a new characteristic. For example, the human gene for insulin can be put into a bacterium, which then produces human insulin. It is done directly in the laboratory, unlike selective breeding. This lets scientists transfer a characteristic across very different species, something impossible to achieve through natural breeding.

How is insulin produced using bacteria?

The human gene that codes for insulin is cut out and inserted into a small circle of bacterial DNA called a plasmid, forming recombinant DNA. The plasmid is put back into a bacterium, which is then allowed to reproduce. As the bacteria multiply, they read the human gene and produce human insulin, which is collected and purified for use by people with diabetes.

What are the concerns about genetic technology?

Genetic technology brings clear benefits such as medicines and improved crops, but it also raises concerns. These include possible effects on human health, unknown long-term effects on the environment and other species, and ethical questions about how far it is right to change living things. A good answer weighs the benefits against these concerns rather than taking only one side, and names a specific example for each point instead of speaking only in general terms.