Hello, my name's Dr.

Warren.

And I'm so pleased that you can join me today for this lesson on genetic engineering, where we're also going to discuss the main steps in how genetic engineering works.

I'm here to work with you throughout the lesson and support you all the way through it, especially the tricky parts.

The learning outcome for today's lesson is I can describe what genetic engineering is, some potential benefits, risks and ethical issues, and the main steps in the process.

And here are our key words for today's lesson.

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

Vector, a plasmid or virus used to introduce a gene from one organism into the genome of another organism.

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

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

The first is on genomes, genes and genetic engineering.

Then we're going to look at the benefits, risks and ethical questions.

And then finally, in the third learning cycle, we're going to look at the main steps in genetic engineering.

So let's get started with our first learning cycle on 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 a chain of nucleotide 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 our 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 material is 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 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 our 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 got B.

That's the correct answer.

So you're doing really well if you got B.

Genetic engineering is an example of gene technology.

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

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 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 genetic 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.

As we're 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 got the correct answer to both of those questions.

Excellent work.

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

We're now going to move on to have a look at the benefits, risks and ethical questions that are associated with genetic engineering.

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 it as a seesaw.

On 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 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're 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 because 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 out-competing 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 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.

Going to have a look at a couple of examples now.

The first one is insulin.

So people with type one diabetes cannot make the hormone insulin to 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 one 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 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, spray 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.

Is it 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 took here, we took a human gene and we put it into the bacterium.

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 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 got those points correct.

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

So this brings us to the end of our second learning cycle, and we're now going to move on to have a look at the main steps involved in genetic engineering.

So the first thing that happens is the gene that codes for a desirable characteristic is identified by the scientists.

And they also have to find out exactly where that gene lies on the genome so that they can isolate it.

A restriction enzyme is used to isolate the gene from the DNA.

Now, you'll remember from previous learning that an enzyme is a protein molecule with an active site.

And that active site is shape specific.

And the right size in this case for the DNA and the part of the DNA with the gene, the desirable gene on, to fit into it.

So the restriction enzyme essentially cuts out the gene from the DNA.

The next thing that needs to happen is that gene needs to be carried to the target cells.

And to do this, a plasmid or a virus is selected as a vector to carry the gene.

Now, you'll remember from previous learning that a virus is simply some DNA with a protein coat.

The vector is acting as the transport.

So once our vector is selected, the restriction enzyme is used to cut the vector DNA open so that we can insert the gene with the desirable properties.

To do this, a ligase enzyme is used.

This is used to insert the desirable gene and an antibiotic-resistant gene into the vector.

At the same time, we need to prepare the target cells.

So cells are extracted from the target organism.

And the vector is used to insert the desirable genes and the antibiotic resistant gene into the target cells.

Now, in reality, not every target cell will successfully have the desirable gene.

So a selection process needs to go on next.

And to do this, antibiotic is used.

So antibiotic is used to select those cells that have taken up the antibiotic-resistant gene.

So what that's essentially saying is we take our cells, we inject some antibiotic into them, and those cells without the resistant gene will basically die, leaving those with the antibiotic resistant gene, and therefore the desirable gene.

Once we have all our cells with a desirable gene in, the genetically modified organisms are grown from those cells and the process is complete.

So we're just going to look at a little bit more detail of how the process happens.

So during the process, the restriction enzyme cuts one strand of the DNA shorter than the other.

And you remember from learning cycle one that the DNA is a double helix.

There are two strands there, and one of them in this case is cut shorter than the other, which leaves what is known as a sticky end.

So the sticky end is the bit that is slightly longer than the other bit.

The ligase enzyme joins the vector DNA and the desirable gene DNA together at the sticky end, and that is how it happens.

Okay, let's have a quick check for understanding.

What we'd like you to do is put the main steps in genetic engineering into the correct order, A, B, C, D or E.

So have a read of those sentences and pause the video while you number them in the correct order.

Okay, so the first thing we do is we use restriction enzyme to isolate the desirable gene.

Then we use the ligase enzyme to insert the desirable gene into the vector.

Then we use the vector to insert the desirable gene into the target cells.

Then we select cells that have taken up the desirable gene, before we grow genetically modified organisms from the selected cells.

So very well done if you've got those in the correct order.

That basically summarises what we have just been talking about and gives you the main steps in genetic engineering, so well done.

So let's have a look at the task.

Genetic engineering has been used to make genetically modified E.

coli bacteria that can produce human insulin.

What we'd like you to do is to make a comic strip to summarise the main steps in the process.

And in your comic strip, do include pictures and explanations.

So let's just remind ourselves, looking at the images here, we have human insulin gene, which we can take and we can put into E.

coli bacteria.

And then we can take that E.

coli bacteria and make it into insulin for injections.

So that should help you to get started.

So pause the video while you have a go at this task.

Okay, let's have a look at a model answer.

So you might have got something like this.

First of all, we want you to use restriction enzyme to isolate the human insulin gene.

Then use ligase enzyme to insert the gene into the vector.

Next, use the vector to insert the gene into the E.

coli cells.

Next, select cells that have taken up the gene.

And then grow the genetically modified E.

Coli from the selected cells.

Then take our GM E.

coli to make human insulin for injections.

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

Make sure that your diagrams are correct as well.

Excellent work.

So that brings us to the end of this lesson.

Let's have a look at our key learning points for today's lesson.

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 one diabetes.

Introducing insecticide genes from Bacillus thuringiensis into crops to protect them against insect pests.

Benefits must be weighed against risks and ethical questions.

The main steps in genetic engineering include isolating the gene that codes for the desirable characteristics, inserting the gene into a vector and using the vector to insert the gene into the cells.

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