Welcome to today's lesson from the unit, Reproduction in Humans.

And the title of today's lesson is Life Cycles and Reproduction.

We're going to be looking at life cycles in general of all living organisms, and then more specifically about the life cycle of humans and how reproduction occurs as one of the main points of that life cycle.

And also how reproduction occurs in the life cycle of plants.

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

You should be able to, by the end of this lesson, explain the role of reproduction as part of the life cycle of humans and other organisms. And with all our science lessons, we've got key words to look out for.

And our key words in today's lesson are sexual reproduction, reproduction, life cycle, growth, and zygote.

Now, here are the definitions for those key words.

Now you can pause the video and copy them down, but we will be going through them at different parts in the lesson as well.

So our lesson today is in three parts.

Life cycles.

So we're gonna look at life cycles, what they are, and the different stages in them and how those relate to reproduction for all organisms. Then we're gonna focus specifically on the life cycle and reproduction in humans.

And then finally, the life cycle and reproduction in plants.

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

So this will be a little bit of a recap for most of you, but just a little bit of a reminder that all living things on earth are either living, dead, or have never been alive.

And living or dead things are called organisms. If they're dead, it means that their life cycle has stopped.

If they're living, their life cycle continues.

And if they've never been living, they don't necessarily have a life cycle.

All living organisms are made from other living organisms in a process called reproduction.

And that is one of the common processes of all living things.

All living organisms eventually die.

And when they die, as we've said before, their life cycle stops.

So all living things are made of cells.

And again, that's a little bit of a recap for you.

And cells contain genetic material in the form of DNA.

So we've got a picture here of a bird, it's an animal.

And if we get zoom in to have a closeup of that skin that's underneath the feathers, we'll be able to see that it's made of these cells.

And if we magnify it even further, we can see one of the animal skin cells.

And the DNA is stored in the nucleus of that cell.

Now, the reason it's really important to know about the DNA being stored for life cycles is because the DNA is passed on in reproduction, and that's one of the stages of the life cycle.

And it's passed on from an apparent organism to its offspring.

So for example here, we've got an adult fox.

And during the stage of its life cycle where reproduction takes place, it's going to pass its DNA onto its fox cub.

And therefore that means that the fox cub is going to inherit the features of its parent because it's received that DNA, which contains the genetic instructions for forming those inherited features.

And also lots of the life processes in the instructions of the DNA.

So as all living organisms have a life cycle, here's an example here of a frog, you might have learned about this life cycle before.

And a life cycle is made up of the stages that a living organism goes through in its life.

Now this life cycle will vary and the stages will differ depending on the living organism.

They're not all the same.

The thing that is the same between all of them is that they all have a reproduction stage, and the rest of the stages are growth.

So here's an example, we've got a rabbit here.

So our rabbit, when it reproduces, produces kittens.

So kittens are the offspring of rabbits as well as cats.

So it can get a bit confusing.

So sometimes people call them kits.

But when a rabbit reproduces, it forms kittens, and then it'll move into a young rabbit, and then into an adult rabbit.

The rabbit produces its young, those kittens.

Then kitten moves to young rabbit, which is growth, and then young rabbit to adult rabbit, which is also growth.

Right, let's have a look at a more complicated life cycle.

So we've got a ladybird.

And when a ladybird reproduces, it produces eggs.

And then it will grow into a nymph, and then growth again into a pupa.

And then finally we've got growth again into an adult ladybird.

Okay, so two quite different life cycles there.

So let's have a quick check.

So this is the life cycle of a newt, and I'd like you to identify using the letter A, B, C, D, or E at which stage reproduction is taking place.

So just pause the video, you can have a quick discussion and decide which one of those it is.

Okay, how did you do with that? The answer is E, hopefully everyone got that right.

And that's when the adult produces its eggs.

So that's when reproduction is taking place.

So your task now.

So I would like you to draw two life cycles.

So you can use the examples on the previous slides to help or your own knowledge, and you need to draw them using the information that's been given below about the butterfly and the penguin.

And you need to use the words growth and reproduction on your cycle.

The same as in that previous example.

The descriptions that you're given are all in a funny order.

They're not necessarily exactly in the order of the cycle, so you're going to have to work out the cycle from the description that you've been given.

So the description for the butterfly is an adult butterfly emerges from a er inside a chrysalis.

It reproduces, lays eggs, and the eggs hatch into caterpillars.

The caterpillars transform within a chrysalis.

And then for the second one, it is a fledgling penguin grows from a hatchling.

The hatchling develops in an egg that is produced by the adult penguin.

So all of the keywords that you need are there, just need to get them in the right order and onto a diagram.

So pause the video while you do this, and then we'll check back to see how you got on.

Right, let's see who you got on with these two life cycles then.

So number one, we've got our butterfly.

So we should have butterfly, then eggs, our adult butterfly, and then our eggs.

Then we should have had a caterpillar and a pupa inside that chrysalis.

And then the stages labelled should be reproduction from butterfly to eggs, growth from eggs to caterpillar, growth from caterpillar to pupil, and finally, growth from pupil to adult butterfly.

So well done if you've got that one right.

Let's have a little look at the next one.

So we've got a penguin.

And we should have adult penguin written there, egg, and then hatchling, and then fledgling.

And on those arrows, we should have reproduction there between the adult penguin and the egg.

And then growth there between the egg and the hatchling, and then growth again between the hatchling and the fledgling, and then growth again between the fledgling and the adult penguin.

So if you've got those two life cycles drawn correctly and labelled, well done.

The next stage of our lesson is reproduction in humans.

Humans reproduce by sexual reproduction.

So, both parents produce the zygotes.

And the zygote is produced because DNA is passed from both parents.

The zygote is the fertilised egg cell, and it's the first living stage of the offspring, which will then grow to form a baby.

So therefore the life cycle of a human is as follows.

So we've got an adult human, then reproduction takes place, and a zygote will form, and then the zygote will grow into a baby, and then a baby into a child, and then a child into an adolescent, and then an adolescent into an adult.

So those are the stages of the human life cycle.

So let's have a quick check that we understand that.

So in humans, the reproduction stage of the life cycle involves producing a baby that grows into a zygote.

Now, is this true or false? And once you've decided, you need to choose which of these statements justifies your answer.

So is it in humans, the reproduction stage of the life cycle involves producing a baby that grows into a new human? Or is it in humans, the reproduction stage of the life cycle involves one parent passing DNA to a zygote? So pause the video while you decide.

Okay, let's see how you did.

So in humans, the reproduction stage of the life cycle involves producing a baby that grows into a zygote.

This is false.

And the best way to justify this is with this statement, that in humans, the reproduction stage of the life cycle involves producing a baby that grows into a new human.

Now for a task.

So pupils are discussing what happens in reproduction after the life cycle.

So now for a task.

Pupils are discussing what happens after reproduction in the life cycle of humans.

And Lucas says, "The zygote is the next stage.

"It contains DNA from the mother only." And Laura says, "A baby is the next living stage, "as it follows on from reproduction." And Izzy says, "A zygote is the next stage.

"It has DNA from both parents "and goes on to grow into a baby." So first of all, what I would like you to do is decide which of the pupils has the correct understanding of the human life cycle.

And then for the other two pupils, I'd like to identify which piece of core knowledge they have not understood, and see if you can correct it.

Okay, so if you pause the video while you do this, then we'll come back to see how you've got on.

Okay, so which of the pupils has the correct understanding of the human life cycle? So it's Izzy, 'cause she said the zygote is the next stage.

It has DNA from both parents and goes on to grow into a baby.

So let's look at the other two responses.

We've got Lucas.

So Lucas said, "The zygote is the next stage.

"It contains DNA from the mother only." So he's got the bit about the zygote being the next stage correct, but his knowledge of the zygote is incorrect as it is the offspring of both parents, and therefore it contains DNA from both parents, not just from the mother.

So let's look at Laura.

Laura said "A baby is the next living stage, "as it follows on from reproduction." And again, Laura's knowledge of growth is incorrect, as the next stage is a zygote, which is living, and then a zygote grows into a baby.

So if you've got those right and you identified where they were wrong, then well done.

So let's move on to the third part of our lesson, which is reproduction in plants.

A plant can also reproduce using sexual reproduction.

So you have two parent plants, and when they reproduce, they produce a seed.

And a seed is the first stage in the life cycle of a new plant.

Now a seed is a living organism.

It's made up of cells, and it carries out some of the life processes.

Some of the other life processes will happen later on in the life cycle.

It will also start to resemble its parents later on in its life cycle.

But it is living and it is the offspring of both of its parents.

So during the reproduction stage of some plants, DNA is passed from both parents.

So we have our two parent plants, and like in humans, both of those parent plants will pass on DNA to their seed.

So therefore the seed is a combination of genetic material in the form of DNA from both parents.

And then that seed, once it germinates, will then grow and form a sprout.

And the sprout is when a little bit of root comes out the bottom and a little bit of shoot comes out the top.

And it's the first stage before we get to seedling.

So here is the life cycle of a plant.

So we have the parent plant which forms the seed, and then the seed forms the sprout, and then the sprout forms the seedling, which is a young plant.

And then that will grow to form the adult plant.

And again, we can put those stages onto our life cycle.

So we've got reproduction between the plant and the seed, and then we've got growth between the seed and the sprout, and then growth between the sprout and the seedling.

And then finally, growth again between the seedling and the plant.

So let's have a quick check on your understanding.

So true or false, a seed is the offspring of the plant.

Is that true or false? Now, once you've decided, which of the statements below justify your answer? Is it A, it is made in the reproduction stage of the life cycle? Or is it B, it is made by reproduction and grows into a seedling that resembles the parent plant? So pause the video while you decide.

Okay, let's see what you got.

So a seed is the offspring of a plant.

That is true.

And the best statement that justifies that is it is made by reproduction and it grows into a seedling that resembles the parent plant.

Right, let's have a practise task now.

So Sam and Sophia are comparing and contrasting a human zygote and a plant seed.

So comparing and contrasting means finding similarities and differences.

And Sam says, "A zygote and a seed are both living." And Sophia says, "A zygote grows inside a female human, "whereas a seed grows in the ground." So Sam has found a similarity and Sophia has found a difference.

So what I would like you to do is write some more features that are similarities, so it's common to both the zygote and the seed, and some features that make them different.

Think about how the seed and the zygote are produced, and also what they're made from to help you with your compare and contrast.

So pause the video while you have a go at that now, and then we'll come back and we'll see what you've got in your list.

So let's see how you got on.

So write some more features that are common to both a zygote and a seed and some features that are different.

So the seed and the zygote both have DNA from two adults.

The seed and the zygote are both made by sexual reproduction.

The seed and the zygote both grow into larger living organisms. The zygote is one cell, but the seed is made up of many cells.

So if you've got any of those correct, then well done.

There's lots of chances for you to do comparing and contrasting in science.

It's a way of you really understanding how things work together.

So we've come to the end of today's lesson, and here is our summary.

So all living organisms have a life cycle which includes the stages growth and reproduction.

In reproduction, genetic material in the form of DNA is passed from parent to offspring.

In humans, the reproduction stage of the life cycle involves producing a zygote that grows into a baby, that grows into an adult human.

And in some plants, the reproduction stage of the life cycle involves producing a seed that grows into a new plant.

So well done for your work on today's lesson on life cycles and reproduction.