What you need to know
- 8.22Risks and benefits of using genetically modified organismAn organism whose DNA has been changed by genetic engineering..
Do not treat a slogan as a conclusion. Medicines from 8C 2 are one benefit. A benefit in one crop is not a benefit in every organism. No instruction to grow or release anything.
By the end, you should be able to…
- Give a benefit of a named type of genetic modification, tied to the trait.
- Explain outcrossing and a risk to a non-target organism.
- Separate a human-health concern from an environmental one.
Build your understanding
A benefit has to be a trait
A genetically modified organismAn organism whose DNA has been changed by genetic engineering. has a new or altered geneA sequence of DNA bases that codes for a polypeptide or a functional RNA. and therefore a new trait. A benefit is what that trait does. Insect-resistant plants can reduce insecticide spraying where that pest is a real problem. A herbicide-tolerant crop can let a farmer use one herbicide on the weeds. A microorganism making insulin supplies a human protein without using animal pancreas. Higher nutrient content is a benefit only if the crop really has that trait.
“GM is good” is not an exam answer. Name the organism, the trait, and who gains. A lower price or a more reliable yield is a benefit to people. It is still a claim about that product, not about every future modification.
Risks are specific too
Outcrossing is the movement of the gene into a wild relative or into a conventional crop, by pollen or by mixing seed. The wild plant might then gain the trait, for example herbicide tolerance, and become harder to manage. That is an environmental and a food-supply risk, not automatically a poisoning.
A toxin made in the plant to kill a pest might also harm a non-target insect that eats the same tissue. An antibiotic-resistance marker used while building the GMO is a concern if that gene were transferred to gut bacteria. The probability may be low. The specification still expects you to be able to state the concern. Allergenicity is a human-health risk if the new protein is an allergen. It has to be tested. It is not assumed.
Hold both columns
A good answer can give one benefit and one risk for the same organism. Insect resistance can mean less insecticide and can also mean a non-target effect or evolution of resistant pests. Neither column cancels the other. Local conditions change the size of the environmental risk.
Labelling and who owns the seed are social questions. You may mention them as concerns people raise. They are not a substitute for the biological risks: gene flowMovement of alleles between populations when individuals migrate and interbreed., non-target organisms, and the new protein itself.
| Claim | Biological point | Too vague? |
|---|---|---|
| Less insecticide where a pest is damaging | Insect-resistance trait | No, if the pest and the crop are named |
| The gene might reach a wild relative | Outcrossing | No |
| GM is unnatural so it is unsafe | No mechanism | Yes. Name a protein, a gene or a recipient |
Make your reasoning visible
One in, one out
Benefit of the trait, then a route by which the geneA sequence of DNA bases that codes for a polypeptide or a functional RNA. or its product could cause harm.
Marker genes
Antibiotic resistance is a selectable marker from 8C 1. As a risk, say where that gene might end up.
Avoid this misconception
The claim: Either GMOs are all safe or they are all dangerous.
The correction: Safety and harm depend on the trait, the organism and the place. Insect resistance, a drug-producing bacterium in a fermenter, and a gene that can escape into a wild relative are three different judgements.
Check your understanding
Try each question before opening the suggested answer.
Practice question
Retrieval and explanation · suggested answer
Give one benefit of a crop that makes an insect toxin in its own tissues.
Show suggested answer
The plant is damaged less by that insect, so less insecticide may be needed where that pest is common. The benefit is the protection, not “GM” in general.
Practice question
Retrieval and explanation · suggested answer
What is outcrossing?
Show suggested answer
The transferred gene moves into a wild relative or a conventional crop, for example by pollen.
Practice question
Retrieval and explanation · suggested answer
Why is an antibiotic-resistance marker a possible risk after a GMO is built?
Show suggested answer
If that gene were transferred to bacteria, those bacteria might become harder to kill with that antibiotic. The probability can be low, but the concern is the transfer.
Take the idea further
Apply the same specification knowledge to an unfamiliar problem. Any extra assumptions are supplied in the question.
Stretch question
A bacterium that makes human insulin is kept in a closed fermenter. A maize plant that makes an insect toxin is grown in a field next to a wild grass that can cross with maize. Compare one risk that is serious for the maize and not for the fermenter. Assume the fermenter waste is sterilised and the wild grass is a real relative.
Show a hint
Which organism can meet another population?
Explore the reasoning
Pollen from the maize can carry the toxin gene into the wild grass, so the trait may persist outside the crop. The insulin bacterium is not released and its waste is sterilised, so it does not have that outcrossing route. The maize benefit, less insect damage, does not remove the gene-flow risk. The fermenter still needs ordinary industrial controls, but those are not outcrossing.
Recall this lesson
Lesson recall questions
Question 1 of 5: List three potential benefits of using genetically modified organisms.
Risks and benefits of GMOs
Practice question
Retrieval and explanation · suggested answer
List three potential benefits of using genetically modified organisms.
Lesson: 8C 4: Benefits and Risks of GMOs
Try this from memory first.
Put your biology to work
Explore where these ideas appear in the world. Enrichment, not extra required recall.
Name the advantage, then name the issue
8C · Benefits and Risks of GMOsWHO says GM foods are developed because of a perceived advantage to the producer or the consumer, such as a lower price, durability or nutritional value, and that…Specification 8.22Read & use the scienceClose article
Why this matters
WHO says GM foods are developed because of a perceived advantage to the producer or the consumer, such as a lower price, durability or nutritional value, and that one objective is improved crop protection. The same page says three debated issues are allergenicity, gene transfer and outcrossing, and that environmental concerns include non-target organisms and escape of engineered genes into wild populations. Use both halves. Do not turn the page into a campaign. 8.22: a benefit is a trait. A risk is a mechanism, such as outcrossing or a non-target effect, not a slogan.
Back to the specification
Pearson Edexcel IAL Biology · Issue 2, February 2021 · Unit 5, pp. 35–38. The application extends beyond required recall.
- 8.22 Benefits and risks of genetically modified organisms.
Use the science
Why is “WHO says GM food is unsafe” an inaccurate use of that page?
Explore a possible response
The page says foods on the international market have passed safety assessments and are not likely to present a risk to human health. It still lists issues that have to be assessed, including allergenicity, gene transfer and outcrossing.
Explore the source
- WHO: food, genetically modifiedWorld Health Organization
A crop trait needs a case-by-case risk question
8C · Benefits and Risks of GMOsThe US National Academies’ evidence review treats genetically engineered crops as a set of technologies and traits, not one uniform product. A plant engineered to resist an insect…Specification 8.22Read & use the scienceClose article
Why this matters
The US National Academies’ evidence review treats genetically engineered crops as a set of technologies and traits, not one uniform product. A plant engineered to resist an insect and one altered for a nutritional property have different potential benefits and different questions for environmental assessment. Gene flow to compatible relatives, changes in pesticide use and effects on non-target organisms need evidence in the relevant setting. The 8.22 skill is to weigh a specified benefit against a specified risk, rather than declare all GMOs safe or dangerous from a label. Published assessments are evidence, not a substitute for local monitoring.
Back to the specification
Pearson Edexcel IAL Biology · Issue 2, February 2021 · Unit 5, pp. 35–38. The application extends beyond required recall.
- 8.22 Benefits and risks of genetically modified organisms.
Use the science
Why would evidence about one insect-resistant crop be insufficient to assess a different crop engineered for nutrition?
Explore a possible response
The inserted trait, receiving species, relatives, farming system and exposure pathways differ. Benefits and risks must be tested for the actual crop and setting.
Explore the source
- Genetically engineered crops: experiences and prospectsUS National Academies of Sciences, Engineering, and Medicine