Hello, my name's Dr.

Warren, and I'm so pleased that you can join me today for this lesson on genetic engineering.

It's part of the Gene Technology Unit.

I'm here to work with you through this lesson and support you all the way, especially through the cheeky parts.

Our learning outcome for today's lesson is, "I can describe what genetic engineering is and some potential benefits, risks, and ethical issues." And here are our keywords for today's lesson.

Gene, a section of DNA carrying the genetic code that provides instructions for a feature or a process.

Genetic engineering, the process of introducing a gene from one organism into the genome of another organism.

Risk, the chance that an outcome, usually a negative one, will occur.

Ethical question, a question about whether something is right or wrong.

You may wish to pause a video now and note down these keywords and their meanings so that you can refer to them later on during the lesson.

In today's lesson, there are two learning cycles.

The first learning cycle is on genomes, genes, and genetic engineering.

And the second on the benefits, risks, and ethical questions.

So let's get started with our first learning cycle on the genomes, genes, and genetic engineering.

All organisms store information in genetic material found in their cells.

The genetic material of all organisms is made from a large molecule called DNA.

DNA is a very long molecule made of chain of nucleoid bases, A, T, C, and G.

So if we look at the diagram, we can see that the DNA has two strands to it.

And in between those strands are the nucleotide bases.

And represented on this diagram, A is in pink, T is in purple, C is in light green, and G is in the darker green.

And it's these nucleotide bases that form the genetic code.

All the DNA of an organism is in its genome.

And if you look at the diagram, you can take a different section and what you see is the code is different.

So different parts of the DNA are separated into different coded codes by the nucleotide bases.

The DNA is wound up into chromosomes, which are found in the nucleus of animal cells, plant cells, and fungi cells.

And you can see on this diagram that the nucleus is represented by an orange circle.

And you can see inside that are chromosomes.

Bacteria don't have a nucleus, but they still have DNA.

The DNA is mainly stored in one large chromosome found in the cytoplasm of the bacteria cell.

And the rest of it is found in small loops of DNA called plasmids, which is also found in the cytoplasm of the bacteria cell.

So let's have a quick check for understanding.

Which statements are correct? A, genetic materials made of cells.

B, bacteria do not have DNA.

C, animal cells contain small loops of DNA called plasmids.

And d, all the DNA of an organism is in its genome.

Well done if you chose d, that is the correct statement.

So, how would you correct the incorrect statement? So have a look closely at a to c and see if you can correct them.

Right, let's have a look at a, genetic material is made of DNA.

Bacteria do not have a nucleus.

Bacteria cells contain small loops of DNA called plasmids.

So very well done if you've got all of those corrections right as well.

Let's move on.

So sections of the chromosomes are called genes.

We have our DNA, we have a chromosome, and if we take any one section, it is a gene.

A gene is a section of a DNA where the code for a characteristic is found.

Now, that characteristic could be something like blue eyes.

It's a feature.

Blue eyes, or blood type A or O, or it could be a process in the organism.

Scientists have developed many ways to modify the genomes of organisms, and one such way is genetic engineering, which we're gonna have a little closer look at today.

In genetic engineering, a gene is extracted from one organism and then inserted into the genome of another organism.

And if you look at this diagram here, we can see we've got a bacteria.

A gene is taken out of the bacteria and it is inserted into a crop plant.

The gene codes for a desirable characteristic.

So if we've got a characteristic we want to have in the crop plant, we can put it in via genetic engineering.

So, again, let's just have a quick check for understanding before we move on further.

Who gives a correct description of genetic engineering? Alex says, "It's the process of extracting a characteristic from one organism and putting it into another organism." Aisha says, "A gene from one organism is taken and then introduced into a different organism," and Lucas says, "A gene is removed from an organism to introduce a desirable characteristic into that organism." So well done if you've got b, that's the correct answer.

So you're doing really well if you've got b.

Genetic engineering is an example of gene technology.

And what it does is it introduces one or more genes into an organism with the aim of introducing one or more desirable characteristics.

So scientists only go and do this if they want to improve or try and improve an organism.

Characteristics that can be introduced include resistance to pests and pathogens.

So certain crops that have little pests, animals that come along and say, eat the leaves.

Via genetic engineering, we can introduce a gene that will be resistant to those pests, so that won't actually happen.

Resistant to chemicals, such as herbicides or weed killers.

So if we spray a crop, the crop doesn't get affected, but the weeds basically die.

The ability to make substances, such as nutrients and medicines, which can then go on and help people.

Tolerances to different climates.

And as climate change occurs around the world, some crops are not able to continue to grow in a certain area, as it may be too hot or dry, but genetic engineering can introduce genes that will allow this to happen.

So, yeah, think about how each of these characteristics can be helpful.

I've already mentioned a few.

You may be able to come up with a few more.

Let's have a look at a couple of examples.

Tomatoes, we all love nice, red, tasty tomatoes.

Well, genetically engineered tomatoes were first sold in 1994 in the USA.

And the genes introduced into these tomatoes made them resistant to fungi and kept them ripe and full of flavour for longer.

And this had a benefit because it meant they could be transported further and had a longer shelf life in the supermarket.

So you think about if you go to the supermarket and you wanna buy some tomatoes, well, these GM ones will last longer when you get them home, or you don't wanna be buying tomatoes that have basically started to rot.

So that is an example of where genetically engineering has been used for the last 30 years.

So let's have a look at another example, this time wheat.

So 40% of the world's population depend on wheat as a staple food.

So that's 3.

2 billion people, a lot of people.

Wheat is used to make flour, flour is used to make bread and pastry.

But one of the issues is our climate around the world is changing, and with changing climates, in some parts of the world, it's harder for wheat to grow in warmer and drier climates, but scientists have found that a gene, HB4, that can be isolated from sunflowers and put into wheat may help the wheat to grow in warmer and drier climates.

And whenever a new genetic modified crop is developed, there has to be lots of trials to make sure that it is safe.

So, currently, trials are underway to grow wheat that's been genetically engineered to include the HB4 gene from sunflowers.

And in fact, in 2020, the first countries started to approve the GM modified wheat.

I think Argentina was one of the first countries, and there have been several others since.

But in other countries, trials are still going on.

So, another quick check for understanding.

Genetically engineered tomatoes were first sold in 1994 in the USA.

How had the genome of these tomatoes been changed? A, genes had been removed from their genome, b, genes had been introduced into their genome, and c, characteristics had been introduced into their genome.

Well done if you chose b, genes have been introduced into their genome.

So, we've come to our first task.

What we'd like you to do in the first question is to write an explanation of the term genetic engineering.

And then for the second question, explain the benefits of using genetic engineering to transfer the HB4 gene from sunflowers into wheat.

And we've given you a diagram there to help you frame your answer.

So pause the video and have a go at these questions.

And then when you're ready, we'll have a look at the answers together.

So, question one, your explanation could be something like this.

Genetic engineering is the process of introducing a gene from one organism into the genome of another organism.

Question two, explain the benefits of using genetic engineering to transfer the HB4 gene from sunflowers into wheat.

Well, first of all, 40% of the world's population, about 3.

2 billion people depend on wheat as a staple food.

So it's an essential part of their diet.

Global warming is causing climate change, but we need to be able to continue growing wheat to feed the world's population.

The HB4 gene could help wheat to grow in warmer climates.

So very well done if you've got the correct answer to both of those questions.

Excellent work.

So that brings us to the end of our first learning cycle.

And now we're gonna move on to look at the benefits, risks, and ethical questions.

The use of genetic engineering has benefits, including ensuring that there's food security for the growing human population, but we must also consider whether the benefits outweigh the risks and also the ethical questions.

So, you can think of as a seesaw.

One side of the seesaw, we have benefits, and on the other side of the seesaw, we have risks and ethical questions.

And what we need to be able to think about is, is it balanced or does the seesaw go one way or the other? A risk is a chance that a negative outcome will occur, such as harm to humans or other living organisms or the environment.

So when considering genetic modification, we definitely need to think, is there a risk to human health? Is there a risk to living organisms or the environment? And an ethical question is about whether it is right or wrong to do something.

So, is it right to change the genome of a plant or a different organism, or should that not be interfered with? So, let's just think about that question of risk.

People tend to underestimate the risks of familiar things, such as travelling in a car.

We all travel in the car every day or nearly every day, and we don't think anything about it because we are used to travelling in cars.

But actually, statistically, there are a lot of accidents on our road every day, and many people get killed every year.

So, actually, the risks of going in a car are quite high.

People often tend to overestimate the risks of unfamiliar things, such as genetic engineering.

And we can get quite worried about genetic engineering if we don't really understand what it is about.

Like most activities, genetic engineering is not risk free, but in most countries, genetic engineering is regulated by law.

And genetically modified organisms can only be used to make food and drugs after lengthy safety trials and government approval.

So it could take many, many years for a GM organism to be approved to be used in food or drugs.

And that is because we don't understand the risks 'cause they're unfamiliar, and we tend to be cautious.

Some people think genetic engineering is wrong, and in different parts of the world, in different times, there have been protests against using genetically modified organisms. And this is because people are concerned about the risks.

For example, unknown or untested effects on genetically modified organisms, safety risks to humans or other organisms, the transfer of genes from one organism to the wild.

And if that happens, we don't know where those genes will eventually end up.

Genetically modifying organisms outcompeting native species and becoming invasive.

So all of these things are things that people are worried about.

And so they also have ethical questions about whether it is right for humans to modify the genome of any organisms. And that's why, because people do have these concerns, because they do have these questions, from time to time, you will actually see protests in different parts of the world.

So, another quick check for understanding.

Which of these are risks of genetic engineering? A, bigger yields of food, b, side effects when eaten, c, transfer of genes into the wild to wild organisms, d, production of medicines.

So well done if you chose b and c.

They're both risks of genetic engineering.

And if you look at a and d, well, they are both positive or benefits of genetic engineering.

So we have benefits as well as risks.

We're going to have a look at a couple of examples now.

The first one is insulin.

So people with type 1 diabetes cannot make the hormone insulin regulate their blood sugar.

And it's a real problem, because for about 22 million people around the world, they need to be treated with insulin injections.

So every day, the people with type 1 diabetes need to inject themselves with insulin so their blood sugar level can be regulated.

Now, going back a number of years, the insulin used to be extracted directly from large numbers of cows and pigs, and you can imagine that this would be quite a difficult task to do because we need to have quite a lot of insulin.

But then in the 1970s and '80s, genetic engineering was used to introduce the human gene for insulin into the bacteria E.

coli.

So medical insulin is now made genetically by genetically modified bacteria on an industrial scale.

And it's probably the process a lot easier to do than to extract the insulin from those cows and pigs.

So, this is an example where a genetically modified E.

coli has real benefits for many people around the world.

Our next example is bacillus thuringiensis.

Insects are pests that damage crops, spread plant pathogens, and reduce yields.

And if you look at this image here, you can see lots of insects on that leaf, and they come along and they eat it.

So they're damaging the crops, eating holes into the leaves, and sometimes spreading disease.

And this can result in reduced yields.

Well, the bacterium bacillus thuringiensis has genes that code for natural insecticides.

And remember, an insecticide is something that will kill those pests, and farmers often spray their crops, or have done in the past, sprayed them with chemical insecticides.

Well, since 1995, these genes have been introduced into potatoes, maize, cotton, and soybeans, which are some of the world's most important crops.

So, we take our bacteria, bacillus thuringiensis, we basically take the insecticide gene, insecticide gene from it and insert it into the crops, such as potato, maize, cotton, and soybeans.

And there have been many trials around the world and they have come up with some interesting results.

First of all, the pests, so those insects that have come and eaten and destroyed the crops are affected.

So that is a real benefit of this genetically modified potato or maize crop.

But one of the downsides is that nearby aquatic insects have also been affected.

And once we start killing off parts of a food chain, they will affect other creatures and organisms in that food chain.

The pollinators aren't affected.

So that's really something that is very positive so that the maize crop, for example, and the cotton crop can still be pollinated and still grow.

And the yields sometimes increase, but not always.

And the reason that they don't always increase is it's complicated because we have factors such as the weather or climates.

So some years it'll be hot and dry, other years it will be cold and wet.

And all of this will affect the yield i.

e.

, how much of that crop is grown.

So, another quick check for understanding.

Which example of genetic engineering involved introducing a gene from a bacterium into a plant? So a, b, or c? Well done if you chose c, bacillus thuringiensis and insect resistance.

So we took that gene from the bacteria and inserted it into the plant.

So for our first example, well, what actually he took here, we took a human gene and we put it into the bacteriums, and then we took a sunflower gene and put that into the wheat.

So very well done if you've got that correct.

And now we come to our second task.

Genetic engineering has been used to make golden rice by introducing genes from daffodils and a bacterium into rice.

The genes cause the rice to make a beta carotene, which is turned into vitamin A.

And if you look at the photograph, you can see that golden GM rice and the non-GM rice, and they really do look different.

Okay, what we'd like you to do is to complete the table on the worksheet to show a, what the benefits could be, b, who might benefit, c, possible risks, and d, ethical questions.

So pause the video while you have a go at this question, and then when you're ready, we'll have a look at the answer together.

Okay, so you might have included, for example, these things, benefits, more vitamin A in people's diets and also improved health.

And this will mean that there is less need for health services.

So very well done if you've got those benefits, who might benefit? Well, the people in areas where diets and health are poor, they're likely to benefit, and also the people selling the golden rice.

So well done if you came up with those.

Possible risks.

Well, untested side effects on humans and other organisms, gene transfer to other species, and golden rice is more expensive.

So all of those are possible risks.

Ethical questions.

Is it right for humans to change the rice genome? And is it right to risk harm to humans and other organisms? So, very well done if you've got those points correct.

Of course, you might have thought of something else, and in which case, those answers may be right as well.

Now we've come to the end of today's lesson.

So let's have a look at our key learning points.

Genetic engineering involves modifying the genome of an organism by adding a gene from another organism.

The aim of genetic engineering is to introduce a desirable characteristic into the genetically modified, or GM organism.

Examples of genetic engineering include introducing the human insulin gene into bacteria to make insulin to treat type 1 diabetes, introducing insecticide genes from bacillus thuringiensis into crops to protect them against insect pests.

Benefits must be weighed against risks and ethical questions.

I hope that you have enjoyed today's lesson and I look forward to learning with you again very soon.