GCSE Biology revision

Genetic engineering

Variation and evolution

AQA 4.1.1.1

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AQA student objectives

Learning pathway

All · Most · Some

ALL 🎯

Identify and describe What is Genetic Engineering?, Real-World Examples of Genetic Engineering and Gene Therapy in the context of genetic engineering.

MOST 🎯🎯

Explain the relationships between What is Genetic Engineering?, Real-World Examples of Genetic Engineering and Gene Therapy and how they contribute to genetic engineering.

SOME 🎯🎯🎯

Apply and analyse knowledge of What is Genetic Engineering?, Real-World Examples of Genetic Engineering and Gene Therapy to interpret unfamiliar information about genetic engineering.

Revision summary

Key knowledge

Read on screen, then print for Cornell-style active revision.

What is Genetic Engineering?

Genetic engineering involves taking a gene responsible for a desirable characteristic from one organism and transferring it into another organism's genome
The organism that receives the new gene is called a genetically modified (GM) organism
Genes can be transferred between organisms of the same species or between entirely different species

1. What is Genetic Engineering?AQA

Notes

Genetic engineering involves taking a gene responsible for a desirable characteristic from one organism and transferring it into another organism's genome
The organism that receives the new gene is called a genetically modified (GM) organism
Genes can be transferred between organisms of the same species or between entirely different species

Real-World Examples of Genetic Engineering

Sheep have been genetically engineered to produce useful drugs in their milk, which can be extracted to treat diseases
Bacteria have been genetically engineered to produce human insulin, which is harvested and used to treat diabetes
GM crops have been modified to improve fruit size and quality, and to become resistant to diseases, insects, and herbicides

2. Real-World Examples of Genetic EngineeringAQA

Notes

Sheep have been genetically engineered to produce useful drugs in their milk, which can be extracted to treat diseases
Bacteria have been genetically engineered to produce human insulin, which is harvested and used to treat diabetes
GM crops have been modified to improve fruit size and quality, and to become resistant to diseases, insects, and herbicides

Gene Therapy

Gene therapy aims to treat inherited disorders caused by faulty genes by introducing a healthy version of the gene into a person's cells
A major challenge is that the faulty gene exists in every cell of the body, making it very difficult to replace it in all cells
One potential solution is to introduce the healthy gene at an early stage of development, such as at the egg or embryo stage, so it is passed on to all subsequent cells

3. Gene TherapyAQA

Notes

Gene therapy aims to treat inherited disorders caused by faulty genes by introducing a healthy version of the gene into a person's cells
A major challenge is that the faulty gene exists in every cell of the body, making it very difficult to replace it in all cells
One potential solution is to introduce the healthy gene at an early stage of development, such as at the egg or embryo stage, so it is passed on to all subsequent cells

Advantages of GM Crops

GM crops can be engineered to have desirable traits such as increased yield or disease resistance, producing more food at lower cost
GM crops are particularly valuable in developing countries where food shortages and starvation remain serious problems
Golden rice is an example of a GM crop that has been engineered to contain beta- carotene, a nutrient that can help prevent blindness

4. Advantages of GM CropsAQA

Notes

GM crops can be engineered to have desirable traits such as increased yield or disease resistance, producing more food at lower cost
GM crops are particularly valuable in developing countries where food shortages and starvation remain serious problems
Golden rice is an example of a GM crop that has been engineered to contain beta- carotene, a nutrient that can help prevent blindness

Disadvantages and Concerns of GM Crops

There is currently no evidence that GM crops are harmful to human health, but scientists cannot yet say with 100% certainty that they are safe
There is a concern that GM plants could escape into the wild and outcompete native species, potentially disrupting entire ecosystems
However, this risk is considered unlikely as GM crops are specifically designed to thrive in farmed conditions, not in the wild

5. Disadvantages and Concerns of GM CropsAQA

Notes

There is currently no evidence that GM crops are harmful to human health, but scientists cannot yet say with 100% certainty that they are safe
There is a concern that GM plants could escape into the wild and outcompete native species, potentially disrupting entire ecosystems
However, this risk is considered unlikely as GM crops are specifically designed to thrive in farmed conditions, not in the wild

How Genes are Transferred: The Process

The desired gene is first identified and cut out from the donor organism's DNA using enzymes
The isolated gene is then inserted into a vector, which is either a virus or a bacterial plasmid (a small loop of DNA found in bacteria)
The vector is introduced into the target organism, where its cells take up the vector and begin producing the protein coded for by the new gene

6. How Genes are Transferred: The ProcessAQA

Notes

The desired gene is first identified and cut out from the donor organism's DNA using enzymes
The isolated gene is then inserted into a vector, which is either a virus or a bacterial plasmid (a small loop of DNA found in bacteria)
The vector is introduced into the target organism, where its cells take up the vector and begin producing the protein coded for by the new gene