Welcome to this lesson from the unit Reproduction in Humans.

The title of today's lesson is Reproduction and Inheritance.

We're gonna be looking at reproduction, which is a common process of all living organisms, and how reproduction leads to offspring, and how those offspring receive genetic material from their parents.

My name's Mrs. Barnard, and I'm going to be taking you through today's lesson.

So by the end of today's lesson, you should be able to explain how reproduction is linked to inheritance.

And as with all of our lessons, there's some key words to look out for today.

So here is a list of the key words.

Reproduction, offspring, genetic material, inherit, and DNA.

This is a slide of the definitions.

Now you can just pause the video and you can write these down.

But don't worry, we're going to be explaining them as we go through the lesson.

Our lesson today is going to be in three parts, making offspring, heredity, and DNA.

So first we're gonna look at how offspring are made through the process of reproduction, how genetic material is passed on, and how that genetic material is stored.

So let's get started with the first part of today's lesson, which is making offspring.

So reproduction is one of the common processes of all living organisms. Now you may remember there are a few common processes.

We tend to list seven, and those are movement, reproduction, sensitivity, growth, respiration, excretion and nutrition.

We sometimes give them the mnemonic MRS GREN as a way of helping us to remember.

So reproduction is the one that we're focusing on today.

So all living organisms reproduce at some point in their lifecycle.

Here are some examples of some lifecycles.

So we've got a butterfly lifecycle here, and we've got a frog lifecycle.

Now you can see that the pink arrow in both cases shows where reproduction takes place.

So with the butterfly, reproduction takes place when the butterfly produces eggs.

From that point forward in the lifecycle, growth takes place, and that's shown by the purple arrow.

So from egg to caterpillar.

And then the caterpillar turns into a pupa, which is inside the chrysalis, and growth is happening there.

And then when that butterfly emerges from the chrysalis, we've got growth there.

So if we have a look at the frog as well, we've got a frog, and reproduction takes place when the frog produces its frogspawn.

And then when the frogspawn grows into its tadpole, then we've got growth, and then tadpole to froglet growth, and then froglet to frog, we've got growth.

So we can see reproduction happens at some point in all life cycles, with the other processes being growth.

So, when organisms reproduce and make offspring, they are of the same kinds, the same species, and the offspring will resemble their parents at some point in the lifecycle.

So let's have a look at one of those species that we just looked at, so a frog.

So you can see this froglet in this picture.

It is starting to resemble its parent.

It's still got the tail, but it's got the legs, the four legs, and it's got the body shape that's a lot more similar to its parent.

Okay, so froglets are the young offspring of a frog, and they will grow from frogspawn.

Then we've got daffodils.

Now when daffodils are bulbs in the ground, they're not resembling their parents, which are those daffodils above the ground with the leaves and the daffodil flower.

But at some point in their lifecycle, they will germinate and they will grow, and then they will resemble their parents.

And the final example we have is humans.

So baby humans do look quite similar to their parents.

They've got arms and legs, and fingers and toes, and a head, but they don't look exactly like their parents.

They're gonna more closely resemble them as they grow into adults.

So the reason that our offspring resemble their parents is because they receive genetic material, and the genetic material that they receive from their parents gives them the instructions for inherited features, and it controls some of the life processes of living organisms. And during reproduction, this genetic material is passed from the parents to the offspring.

So let's have a little look at an example.

We've got some lions here.

So we've got a male lion and a female lion, a lioness.

And when they produce offspring, look at this little cub, it's very cute, it will have a full set of genetic material in order to give its instructions for its features, but also for its life processes.

Now, in order to have a full set of genetic material, it means that it gets half of its genetic material from its father, and half of its genetic material from its mother.

So time for a quick check.

So all offspring resemble their parents.

So want you to decide whether that statement is true or false.

And once you've decided whether it's true or false, which of those statements below best supports your answer? Is it that they receive genetic material from both parents, so they look similar to both? Or is it they receive genetic material from both parents, so look similar to both at some point in their life cycle? So if you pause the video while you answer this, and then we'll come back and have a look at your answer.

Okay, how did you get on with that? So all offspring resemble their parents, so that is true.

And the best statement that justifies that answer is the second one, because they receive genetic material from both their parents, so they look similar at some point in the lifecycle, as we saw with those examples earlier.

So let's go to a practise task.

So now we've got three adult organisms, and we've got three offspring.

So the first part of this task is to match the adult with its offspring, so a letter and a number.

And then once you've matched them, I want you to explain how you decided that that offspring match.

So in detail, what is it that made you realise that that offspring did come from that adult? So you need to be quite descriptive in your explanations.

So if you pause the video while you do that, and then we'll come back and we'll look at your answers after.

Okay, let's see how you got on with this task then.

So first of all, we have got A-2.

So we've got a lady bird and a lady bird nymph.

Now, you might have seen these lady bird nymphs when you've been out and about and not realised that they were the offspring of lady birds.

But out of those choices, that was the one that looked the most similar.

Now, some of the descriptions you might have given or explanations for that would be that they're both insects, and therefore they both have an exoskeleton.

So that's like the shell that's around the outside.

And they both have six legs.

You may have said other things about the fact that they're insects, like they are made up of three body parts, for example.

You might have mentioned the colour.

They've got similar coloration.

Okay, so any good explanation for why you put that offspring with that adult is correct.

Next one, we've got B-3.

So these are our mice.

And the reasons that these are the offspring is that they look similar to the adult.

They're brown coloured mammals.

They have fur.

They've got four legs.

They've got a tail, okay.

You might have come up with some other answers.

You might have said the shape of the ears, or they've got big ears, for example, okay? So anything that is a good explanation for why you chose the offspring is correct.

And then the next one, we've got flamingo C-1, and you could have said they look similar shaped.

They've both birds.

They have got two legs, they've got wings, and they've got a beak, okay? You might have said they've also got a long neck, for example.

Okay, so if you got any of those descriptions correct or any alternative descriptions, okay, which showed that you were working hard to come up with an explanation, then that is correct and well done.

So let's move on.

There's another task for you to do now.

So for each of the keywords, can you match the correct definition? So our keywords are lifecycle, offspring, reproduction, organism, and genetic material.

So again, pause the video while you match the keywords to the correct definition.

Okay, let's see how we got on.

So lifecycle.

So a lifecycle is the stages a living organism goes through in its life.

Offspring is the young of adults produced following reproduction.

Then we've got reproduction, which is a process carried out by all living organisms. Then we've got organism, which is a living thing that is made up of cells.

And then we've got genetic material, which is the information that is passed on from one generation to the next by reproduction.

Okay, so if you've got all of those correct, then well done.

And it's time to move on to the second part of our lesson, which is heredity.

Heredity is the passing down of features from both parents to their offspring.

And the features result from instructions in an organism's genetic material, so that genetic material that has been passed on.

And it is passed on to the parent during reproduction, as we looked at in the previous part of the lesson.

An organism inherits half of its genetic material from each parent.

And we can see in these examples here, so the lion that we looked at before, we can see that cub there does resemble its parents, and it does that because it's received genetic material from both of its parents.

And that puppy there definitely resembles its mother there because it has the genetic material that has been passed down from the mother.

There would be a father in this case as well.

But bacteria also reproduce to make offspring.

So the examples that we've looked at so far are animals, and we looked at those daffodils, those plants to show that genetic material can be passed on, and therefore those organisms look like their parents at some point in their lifecycle.

The difference with bacteria is that they do reproduction with only one parent.

So during reproduction, the genetic material is passed on to the offspring from their parent.

Now, the way that that occurs is that the parent will copy its DNA, its genetic material, and then the cell will grow, and then it will divide in order to form offspring.

Now, this is a very different process from what we were looking at with the previous animals.

However, the core process is the same in that the genetic material is passed from the parent to the offspring, in order that the offspring will have those inherited features and life processes.

Many of the features that are inherited can be seen when the offspring is produced.

So for example, this puppy here looks really similar to its parent.

The fur colour, the black nose, and the lighter coloured fur, the ears, the shape of the body.

We can see that immediately in that young puppy.

But in some examples, the offspring don't look like the parent.

So we can see the frogspawn here doesn't look very much like the frog.

It still contains the genetic material from the frog, but those features will not be apparent until some point later in the lifecycle.

Not all the instructions that are received through the genetic material are for features.

In some examples, they're for life processes, such as digestion or growth.

And that can be shown in this seedling, which has germinated from a seed and grown because of the instructions that are in the genetic material.

Now, offspring that are from the same parents will still receive features from both of their parents.

However, each offspring inherits a different combination of genetic material from their parents.

So you can see with these brothers and sisters here, these siblings, we can definitely see that they're related to each other.

They look similar and they will look similar to their parents as well, but they don't look identical, okay? So there's variation between them, although we wouldn't mistake them as being from a different species.

They are certainly related to each other, so they look similar, but there is variation.

So let's do a quick check.

So what does the genetic material provide instructions for? Is it inherited features, language, skills, or processes, such as growth? Okay, make your choice and then we can check back.

Okay, so there are two in this list.

The first one is inherited features, and the second one is processes, such as growth.

Okay, another check.

So we've got a true or false here.

Children are identical to their parents.

Is that true or false? And when you've decided which of the statements best justifies that answer, is it that they receive more genetic information from one of their parents? Or is it that they receive half the genetic information from each parent, so that they have a unique combination? Okay, make your choice and then check back.

Right then, so the correct answer is false.

Children are identical to the parents, that's not true.

And the best justification for that is that they receive half their genetic information from each parent, so they have a unique combination.

Right, it's time for a task now.

So Aisha and Sam are discussing which of the following organisms can be called offspring.

So we've got a shield bug and eggs, a tiger and cubs, and dividing bacteria.

And Aisha says, "I think only the bacteria and the tiger cubs are offspring, as they look similar to their parent.

Genetic information has been passed down." And Sam says, "I think the eggs and the cubs are offspring, as they have genetic information from two parents." Now, in both these cases, Aisha and Sam are incorrect, although they do use some correct key words, and that's worth noting, okay? And some of their ideas are correct too, they've just not quite put them together correctly.

So what I'd like you to do is write an explanation for why all three of the images are all examples of offspring.

Use some of the ideas that Aisha and Sam have in order to structure your answer.

So pause the video and come back when you have done your writing.

Okay, let's see how we've got on.

So write an explanation for why all three of the images are all examples of offspring.

So just a reminder, Aisha said, "I think the bacteria and the tiger cubs are offspring, as they look similar to their parents, so genetic information has been passed down." And Sam said, "I think the eggs and the cubs are offspring, as they have genetic information from two parents." So some of their ideas are correct, remember.

So in your explanation, these are the things that you could have included.

So the tiger cub, the eggs, and the bacteria are all examples of offspring.

They all resemble their parents at some point in their lifecycle.

And they have received genetic material from their parents, one parent in the case of bacteria.

So if you've got those in your answer, then well done.

And it is time for us to move on to the third part of our lesson.

So the third part of our lesson is DNA.

So the genetic material of all organisms is made of a chemical substance, and that chemical substance is called DNA.

So we've got an animal cell here, and an animal cell has a nucleus, and within its nucleus, it stores the DNA.

You can see it's a very long molecule there.

Other organisms that have cells that have a nucleus are plant cells and fungi.

So DNA is a long chain of molecules that are joined together.

So it's a really, really long chemical molecule.

And it's made of smaller chemical molecules, which scientists call A, T, C and G.

That's where they're located as part of the DNA molecule.

And those smaller chemical groups, A, T, C, and G form the genetic code.

Now, the code provides instructions that build all of the inherited features, and control life processes of all living organisms. So it doesn't matter whether it's a bacteria, or a plant, or an animal, all of them have the same genetic code, so the same A, T, C and G.

But the order that those letters is in gives the instructions to provide different features and different processes.

So here we go, we've got an adult monkey, and it passes on its DNA through the process of reproduction to its offspring, an infant monkey.

And then the offspring then inherit the features and processes, because those features and processes are determined by the code that is in that DNA.

So if you pass the code from the adult to the offspring, then that offspring then have the code in order to build those inherited features and processes.

In animal, plant and fungi cells, the DNA is stored in the nucleus.

So there's an animal cell, and this is the nucleus.

So the nucleus inside the cell, then we're just taking the nucleus out there so we can look at it a little bit more closely.

And it's organised into these packages called chromosomes.

Now, chromosomes are just big bundles of DNA.

So you take that really, really, really long molecule, DNA, and then you wrap it up, and you turn it into these strange shaped balls of DNA or packages that are called chromosomes.

And these chromosomes are passed from parents to offspring, and that happens during reproduction.

So if the offspring then have these chromosomes, it means that they've got the DNA with the genetic code that allows them to build those inherited features and control life processes.

So let's look at an example of how we can explain this process looking at fur colour.

So we've got a mother cat here, it's got black fur, and the black fur is produced using the instructions in her genetic code.

And then the father is a white cat, and his white fur is produced using instructions in his genetic code.

So the parent's genetic code, so in both examples, the mother and the father, that's carried by DNA, and it is packaged into chromosomes.

And then they pass the chromosomes to the offspring during reproduction.

And because that offspring now has those chromosomes, it has black and white fur, because it has the genetic code it received from both of its parents.

So let's see if we can put some of these statements in order with a quick check.

So the statements are, the chromosomes are passed to the offspring in reproduction, the DNA is packaged into chromosomes, the genetic code is carried by the DNA, and the offspring inherit the features of their parents.

So put those into order, and then pause the video, and then we will come back and check on your answer.

Okay, let's see how we got on.

So the first part of the explanation would be that the genetic code is carried by DNA.

The second part would be that the DNA is packaged into chromosomes.

And then the third part would be that these chromosomes are passed to the offspring in reproduction.

And then the fourth part will be that the offspring inherit the features of their parents.

So in this task, we've got Jun, and he's explaining how this kitten has inherited its fur colour from its parents, and he has a sentence to start his explanation.

"The ginger fur of the mother is produced using instructions in her genetic code." So what I would like you to do is to complete Jun's explanation.

But you can start by using his sentence.

So copy down his sentence to begin with, and in your response, can you include the key words, reproduction, genetic code, DNA, and chromosome.

Now if you need a little bit of help, you can go back to the previous two slides, which will help you to model out your answer.

So you'll need a little bit of time for this extended response.

So if you pause the video and then come back when you're complete.

Okay, let's see how you got on.

So to complete Jun's explanation, we copied down his sentence to start with.

So the ginger fur of the mother is produced using instructions in her genetic code, and therefore the black and white fur of the father is produced using the instructions in his genetic code.

And the genetic code is carried by the DNA, and the DNA was packaged into chromosomes.

And the chromosomes were passed to the offspring during reproduction, and therefore, the offspring has ginger, black and white fur, and this is produced using the genetic code that it received from both of its parents.

You can see that the keywords there are all highlighted in blue, so I hope that you included all of those in your explanation, and if you did, then well done.

So it's time for the end of our lesson now, and we've got our summary of reproduction and inheritance.

So our summary is as follows, "All living organisms develop from other living organisms. Reproduction is the process of making new living organisms called offspring.

When organisms reproduce, they make offspring of the same kind that looks similar at some point in their lifecycle.

Offspring inherit features from both parents, so they look similar to their parents and one another.

Features are inherited when genetic material in the form of DNA is passed from parents to their offspring during reproduction.

And the DNA is stored in chromosomes, and it carries the instructions for inherited features and processes." Well done for your work on today's lesson.