Hello, my name is Mrs. Mehrin.

And I am so excited to be learning all about microorganisms living on food.

And we are going to be planning and doing today.

Welcome to today's lesson from the unit, Why We Group and Classify Living Things.

Your lesson outcome today is, I can predict what happens when food is left to decompose over time.

Now, I know that learning can sometimes be a little bit challenging.

But that's okay because it just means that we are going to work really hard together and we are going to learn lots of fabulous new things.

Now here are all of your keywords for today.

Now, please don't worry about writing these down because I will be going over them throughout today's lesson.

But if you find that it does help you, that's absolutely fine and you can jot those down now.

Okay, off you go.

Fantastic.

Well done.

And here are all of the definitions for your keywords today.

Now, again, you don't need to write these down because I will be going through these throughout the lesson.

But if you find that it does help you, you may pause the video now and jot them down.

Off you go.

Fabulous.

Well done.

Now, our lesson today is split into three parts.

Let's begin with the first part, mould.

Now, Jacob had to have cereal instead of toast for breakfast this morning because he noticed that his bread had gone mouldy.

Now, what do you know about mould already? I'll give you five seconds to think about your answer.

If you need longer, you can pause the video.

Off you go.

Fantastic.

Well done.

So mould is a microorganism.

It is a type of fungus and can be grouped with other fungi such as yeast, mushrooms, and truffles.

Now, here, we have a picture of mould, yeast, mushroom, and truffles.

Now mould feeds and grows on something called organic matter.

So here we have mould growing on wood.

And it can grow on anything that has come from plants or animals, including wood from trees and clothing made from cotton.

Now let's do a quick check of your learning.

It says what type of microorganism is mould? Is it a, bacteria, b, virus, or c, fungus? Okay, I'll give you five seconds to think about your answer.

But if you need longer, you can pause the video here.

Off you go, What it said, what type of microorganism is mould? The answer is c, fungus.

Now it says, which of these objects could mould grow on? A, a wooden chair, b, carrots, or c, dry and clean plastic bottle.

So I'll give you five seconds to think about your answer.

If you need longer, you can pause the video here.

Off you go.

Fantastic.

Well done.

The answer is a and b.

Now mould reproduces by releasing tiny spores that float through the air.

And here, we have a picture of mould spores under a microscope.

And these spores are so small we can only see them using a microscope.

And when the spores land somewhere with the right conditions, mould can grow.

Now mould takes in nutrients from the organic matter it grows on.

And it releases digestive substances onto the organic matter, which breaks it down or decomposes it.

And the mould then absorbs nutrients from the decomposed matter through microscopic threads called hyphae.

And here, we have a picture of hyphae under a microscope.

Now, let's do a quick check-in of your learning.

It says, how do moulds reproduce? Is it a, by producing and dispersing seeds, b, by producing and releasing spores, or c, by producing offspring? Okay, I'm gonna give you five seconds to think about your answer.

If you need longer, you may pause the video here and you can come back once you have an answer.

Off you go.

Fabulous.

Well done.

The answer is b, by producing and releasing spores.

Now, how do moulds take in nutrients? Is it a, by eating and digesting food, b, by digesting organic matter and absorbing them through hyphae, or c, by absorbing them through roots.

Okay, I'm going to give you five seconds to think about your answer.

If you need longer, you may pause the video here.

Off you go.

Fabulous, well done.

The answer is b, by digesting organic matter and absorbing them through hyphae.

Now some children are talking about mould.

Andeep says, "Some plants take in nutrients through roots, and mould takes in nutrients through hyphae, which are like roots.

I think moulds are a type of plant." And Sofia says, "I agree.

Mould can be green and yellow, and so can plants." What do you think? I'll give you five seconds to think about your answer.

Off you go.

Fabulous.

Well done.

Now, all plants make their own food using photosynthesis.

And here we have a picture of mould growing on an orange.

Now mould cannot make its own food.

So it's not a plant, it's a microorganism.

And mould gets its nutrients from the organic matter it's growing on.

Now there are over a hundred thousand different types of mould.

And many of these types of mould can be harmful if they get into our bodies.

Now mould that we find growing on food can make us unwell if we eat it.

And you should never eat food if you find mould growing on it.

It should be thrown away or added to a compost heap.

Now, hyphae and spores from mould are invisible to the naked eye.

And here we have hyphae under a microscope.

Now this means that there could be mould on food even if we can't see it.

And food with mould on should not be eaten because there may be spores or hyphae that we cannot see contaminating it.

Now some types of mould can also be helpful.

Now, penicillium mould is used by scientists to create an antibiotic medicine called penicillin.

And some types of mould can be used to make strong-tasting blue cheeses like Stilton.

So here we have a picture of the penicillium mould and a Stilton blue cheese.

Now, true or false, humans have no use for mould and it should never be allowed to grow.

Is that true or is that false? I'll give you five seconds to think about your answer.

Off you go.

Fabulous, well done.

The answer is false.

Now let's see if you can justify your answer.

Is it because some types of mould are helpful for making food or medicine, or b, mould is a type of fungus, and all fungi can be eaten by humans? Okay, again, I'll give you five seconds to think about your answer.

Off you go.

Fabulous, well done.

The answer is because a, some types of mould are helpful for making food or medicine.

Now here is your first task.

It says, are these statements about mould true sometimes, always, or never? So for each one, explain how you know.

So you've got 1, mould is harmful to humans, 2, mould grows on organic matter, and 3, mould is a type of plant.

So I'm going to give you some time now to pause the video here and have a go at this activity.

Off you go.

Fabulous.

Well done.

Now, you may have written something similar to this.

So number 1, mould is harmful to humans.

So you may have written this is sometimes true because there are some types of mould we can eat, like the ones used to make some kind of cheeses.

Number 2, mould grows on organic matter.

So you may have written, this is always true because mould needs nutrients from organic matter to be able to grow.

And for the last one, mould is a type of plant.

So you may have written something like, this is never true because mould is a type of microorganism, not a plant.

Plants make their own food using photosynthesis, and mould cannot do this.

Now we are onto the second part of our learning today, which is observing mould growth over time.

So mould is a living thing.

Just like other living things, it needs certain conditions to survive, grow, and reproduce.

Now it needs moisture, warmth, and nutrients to grow well.

And here we have a picture of mould growing on a potato.

Now, which of these does mould need to grow? Can you remember? There's a, darkness, b, sunlight, c, warmth, d, moisture, or e, nutrients.

So I'll give you five seconds now to think about your answer.

But if you need longer, you can pause the video here.

Off you go.

Fabulous, well done.

The answers are c, d, and e, warmth, moisture, and nutrients.

Now mould will grow on most organic matter eventually, but there are some conditions that allow it to grow much more quickly.

Now mould grows quicker if it's warm and it's damp.

So if there's warm and damp conditions, then mould is likely to grow much quicker.

Now mould is common in moist foods, such as fruit, bread, cheese, and meat.

And it takes much longer for mould to grow on very dry foods, such as crackers or uncooked pasta.

Now which of these foods is likely to grow mould the quickest? A, dried beef, b, raspberries, c, raisins, or d, dry cereal.

So I'll give you five seconds now to think about your answer.

But if you need longer, you can pause the video here.

Off you go.

Fabulous.

Well done.

So b, it would be the raspberries where mould is likely to grow the quickest.

Now mould can also grow on materials that aren't food for humans, such as wood or fabric from a cotton plant, for example, and paper from trees.

Now Lucas would like to observe how mould grows on different foods, but he knows that moulds can be harmful.

Now he plans to put some foods into plastic bags and then leave them for two weeks to observe what happens.

Now what could he do to help keep himself and his friends safe while he's carrying out this observation over time inquiry? So I'll give you five seconds to think about your answer.

If you need longer, you can pause the video here.

Off you go.

Fantastic.

Well done.

So Izzy says, "He should keep his food away from other foods that people will be eating." So that's a really good advice.

Laura said, "He should keep his mouldy food in a place where no one will eat it by mistake." Jun says, "He should not touch his mouldy food with his bare hands." So another piece of really good advice there.

And Alex says, "He should keep his food sealed in the bag." Now, did you have any other ideas for what Lucas could do? I'll give you five seconds to think about your answer.

Off you go.

Fabulous.

Well done.

So let's do a quick check-in of your learning so far.

Why is it important for Lucas to follow strict safety rules when he's carrying out his mould inquiry? Is it because a, mould can be harmful, b, because mould looks unpleasant, or c, because mould is too dangerous for us to observe at all? I'll give you five seconds to think about your answer.

Off you go.

Fantastic.

Well done.

The answer is a, because mould can be harmful.

Now Lucas wants to measure the area of mould growth, so he draws a one centimetre by one centimetre grid on the front of the bags he's going to put the foods into.

And he puts a piece of paper inside while he's drawing the grid to make it easier.

Then he makes two tiny holes in the top of each bag using a pin.

And this will allow a small amount of air to get into and out of the bag when it seals.

Now, why do you think he does not want a lot of air to move out of the bag? I'll give you five seconds to think about your answer.

Off you go.

Fabulous.

Well done.

So mould spores can travel in air, and he doesn't want lots of harmful mould spores leaving the bag in case they make someone unwell.

Now Lucas decides to observe bread, cheese, and apple over time to see how mould grows.

And he adds a slice of each food to a bag and seals the top.

So here we've got bread, the apple, and the cheese.

And he leaves them in a safe place for two weeks to see what happens.

Now Lucas knows that mould can be harmful, so he takes some safety precautions every time he makes an observation.

He never opens the bags with his food inside.

He washes his hands every time he's made observations.

And when he has finished his inquiry, his teacher will dispose of the bags safely.

Now let's do a check-in of your learning.

Which of these would be a good place for Lucas to store his foods while he waits for them to grow mould? Would it be a, in the fridge, b, in the freezer, c, in his lunchbox, d, on a shelf in the classroom, or e, on his table in the classroom? Okay, I'll give you five seconds to think about your answer.

Off you go.

Fabulous.

Well done.

It should be d, on a shelf in the classroom.

Now, you're going to follow the instructions to set up your own observation over time inquiry to see how mould grows.

I want you to make sure you follow all the safety rules when setting up your inquiry and making observations.

So number one, it says prepare the bags for your food.

You will need to think about how you can measure the growth of mould over time.

Izzy says, "I'm going to use a grid that has been photocopied onto an acetate sheet and hold it over the top of my food to make observations.

And Alex says, "I'm going to draw a one centimetre by one centimetre grid on the bags." Number two, you need to choose the foods you would like to observe and add them to your bags.

So Izzy says, "I'm going to use a slice of white bread and a slice of brown bread to see if there's a difference." And Alex says, "I'm going to use a slice of bread, some cheese, and a slice of apple." Then I want you to fully seal the bags and put your bags in a safe place.

Then after this, you are going to make observations of the growth of mould over time, and you can decide how often to make observations and what to record each time.

So Izzy says, "I'm going to wait two weeks, then compare the amount of mould on each of my three foods." And Alex says, "I'm going to record the area of mould in centimetre squared every three days." Now, I want you to have a go at that activity.

So I'd like you to pause the video here.

Remember, you can go, you can rewind from here and have a look at those instructions again if you need them, and that would be absolutely fine.

So I'd like you to pause the video now and have a go.

Off you go.

Fabulous, well done.

So Alex decided to draw a table to record his observations.

And he is asking, "How did you decide to record your findings?" So it could have been that you decided to do it like this.

Now we are onto the final part of our learning today.

It's all about making predictions.

Now scientists can make predictions about what will happen in an inquiry based on what they already know and what evidence they have.

Now we can make a prediction about what will happen to our food using what we already know about mould.

Now, what do you know about mould already? I want you to think about what we've learned today, as well as times you have seen mould growing on food.

Okay, I'd like you to pause the video here and have a go at this.

Off you go.

Fantastic.

Well done.

So Sam says, "At home we keep cheese in the fridge but not bread.

I think this must have something to do with preventing mould from growing." And Jun says, "I've seen apples with blue mould on the ground under apple trees before." And Sofia says, "I have learned that mould grows best in warm, moist conditions." Now these children are going to use what they already know to make predictions about what will happen in their inquiry.

Sam says," I think my cheese will go mouldy faster than my bread because cheese needs to be kept in the fridge." Jun says, "I think the mould will be green on the bread but black on the apples because that's what I've noticed before." And Sofia says, "I think that the apple will go mouldy the fastest because it's more moist than the bread.

Now let's do a quick check-in of your learning.

It says, how do scientists make predictions? Is it a, they choose equipment carefully, b, they make a guess based on their gut feelings, or c, they use evidence that they have to think about what is likely to happen? So I'll give you five seconds now to think about your answer.

Off you go.

Fabulous, well done.

The answer is c, they use evidence they have to think about what is likely to happen.

Now here is your final task for today.

It says, make a prediction about how the mould will grow differently on the different foods you've used for your observation over time inquiry.

Use what you have learned about mould, as well as evidence from your own life.

And justify your thinking, explaining why you have made this prediction.

So I'd like you to pause the video here and have a go at this activity.

Off you go.

Fabulous.

Well done.

So Aisha says, "I predict that the cheese will go mouldy the fastest because we usually keep it in the fridge, and I know mould grows better in warm conditions like my classroom.

And Jacob says, "I predict that the apple will grow mould very quickly because it is very moist, and I have learned that moist conditions are better for moulds." Now we are onto the summary of your learning today.

So mould is a microorganism.

It's a type of fungus.

Mould needs moisture, warmth, and nutrients to grow well.

It is common on moist materials and foods such as fruit, bread, cheese, and meat.

We can observe mould growing over time if we carefully follow safety rules.

And scientists can make predictions about mould growth based on the evidence they have.

Now, you have worked really, really hard today.

I'm so proud of you.

There's been lots of new vocabulary to learn and lots of new things to learn as well that you have done wonderfully.

Well done.