Name the organism in a food chain that goes on the bottom of a pyramid of numbers.

Select the correct pyramid of numbers for the following food chain: Oak trees -> Winter Moth Caterpillar -> Great Tits -> Sparrowhawks

Select the correct pyramid of biomass for the following food chain: Oak trees -> Winter Moth Caterpillar -> Great Tits -> Sparrowhawks

If the key of a pyramid of numbers states that 10 organisms equals 1 square, how many squares would 100 organisms be?

What is the definition of biomass?

How is energy transferred from organisms at one trophic level in a food chain to organism at the next?

How is energy lost to the surroundings at each trophic level in a food chain?

Representing Food Chains

﻿Hello, welcome to the next lesson on ecological relationships and classification. This is lesson three of the topic and it's on decay. My name is Miss Lewis if you haven't met me yet and today you are going to need just a pen and paper in front of you. Also make sure you're in a quiet space. So you can really focus on today's lesson. And you've not got any distractions around like a phone or notifications going off. Pause the video now to make sure you've got everything you need to have a great lesson. So this is what we're doing in today's lesson. First up is the cause of decay, and then we're going to look at why it's important. The conditions that we need for decay to happen, and that leads on nicely to the features of a compost bin. And at the end of the lesson you will complete the exit quiz. The big question today is why does an apple rot? If you've ever left fruit in the fruit bowl too long or you've seen it lying around on the streets and it goes very, very mouldy. We're looking at why does that happen? Well, decomposition or decay is another word for rotting. Let's practise saying that word, decomposition. say it, one more time, decomposition. Excellent, so decomposition or decay means the breaking down of organic matter or the breaking down of living things. So here is our apple, showing the process of decomposition. Breaking down over time. And there are small little organisms that help break down this dead matter. They carry out the process of decomposition. So they are called decomposers. There are two different types of decomposers. The first type of decomposer, are these, detritivores. That's quite a difficult word to say. So let's try again, detritivores, you go. Detritivores. So detritivores are like the images on the screen, worms, lice, slugs, beetles, and what they do is they break down the dead matter into smaller pieces. Like in this example. Any one of these organisms could die at one point. And when they die, it's the detritivores that breaks them down into smaller pieces. So what are these called again? Detritivores, well done. The other type of decomposer is microbes or micro organisms. These include bacteria and fungi. The role of the microbes is to use the small pieces of dead matter in the process of respiration. This process also uses oxygen to release energy. And as a result, carbon dioxide and water is also produced. What are these called again? Microbes or micro organisms. And what is the process that they carry out? Respiration to release energy. So when these decomposers break down the living matter compost is produced. And compost contains lots of mineral ions that are really useful to the producer. That'll help it grow. So what farmers and gardeners do, is they put compost on their soil to help improve the quality of the soil. And what that does, is it returns the mineral ions to the producer and recycles the substances. This is really important because it saves us from using more resources. And instead we're just using stuff that was already there. So, I got some questions for you, what is the name of the process When dead plants and animals are broken down? 10 seconds to pick your answer. Hopefully you said decomposition. Practise saying it again if you're not sure, decomposition. Which of the following is an example of a detritovore? 10 seconds again, to pick your answer. That 10 seconds is up. The answer is a worm. The worm is the only example of the detritivore the others are microbes or microorganisms. And what is the role of microbes? I'll give you 20 seconds on this one. The role of the microbes is to release mineral ions back into the environment and they do this by the process of respiration. What do farmers use compost for? 10 seconds. The answer is to improve soil quality. Well done if you did that. They're returning those mineral ions back to the producers to their plants and crops to help them grow. Now, the rate of something, how quickly it happens, can be changed by different factors. And we're going to look at the factors that increase the rate to make it faster and also slow down this process of decomposition. On the screen are the three factors. What are they from the images? The three factors that change the rate, the speed of decomposition, are temperature, water, and oxygen. And we're going to have a look at these in a little bit more detail. So the first question we're going to answer is why do we keep our food in the fridge? When temperature is cold or it's a low temperature then decomposition happens very slowly. The microorganisms and the detritivores or the decomposers are not very active. So the rates at which decomposition happens is very slow. As we increase the temperature though, the decomposers are more active. So decomposition happens faster. The food or dead matter can be broken down even quicker. However, if it gets too hot, the decomposers die. And so the rate of decomposition doesn't happen at all. You might have seen UHT milk in the supermarket or have it at home. That's what they do to this milk. They expose it to really high temperatures so no decomposers can survive. Really low amounts of water also have an effect on decomposition. These decomposers need water in order to survive and carry out the processes when they break down the food. So when water's really low, no decomposition happens at all. Because the organisms can't survive. As we increase the amount of water though decomposition happens faster and faster. So the rate gets even quicker because the decomposers can survive and break down the substances. Why do we wrap off food in clingfilm then? Remember we said the decomposers respires. And when they respired, they need oxygen for this to happen. So oxygen will also affect the rate of the composition. The more oxygen there is, the more that the decomposers can respires, they can grow, and they can multiply. And so the breakdown of food will happen even quicker. This is why we put clingfilm on our food, to stop any oxygen getting in and slow down this happening. Let's see what you've learned then. Read through the following statements and decide whether they are true or false. If they are false, you need to rewrite the statement. So it's correct. Pause the video now and resume when you're done. Are you finished? You sure, have you corrected each of the statements? Here are the answers. Here you can see which answers are true and which ones are false and you can see the corrections I've made to the false statements. It's really important you correct your work. So please do this now, pause the video so you can do that properly. Well done if you got all of them right. The next question we're going to answer is how farmers make the best compost. We already looked at what compost is. That it contains all these mineral ions that plants need and that it's formed when the dead matter is broken down by the decomposers. And it's vital because it improves soil quality. But how do farmers make it? And make it quickly? This is a compost bin. So compost bins are used by gardeners and farmers and even maybe you've got one at home, a little one in your kitchen. And what you do is you put all the dead matter from living things in there. So that could be a banana peel, leftover bones from your chicken dinner, or maybe even cores of apples, all the things that you don't eat. But the stuff that is really good for making compost. This bin is where the compost is broken down. So it needs to have certain features so that this can happen even quicker. And we use those three factors, temperature, water and oxygen to make sure the conditions are just right. Pause the video now and have a think, what sorts of features might the bin have? Let's have a look and see if you said any of these. So first of all, the outside of it needs to be a dark colour and that is so it can absorb heat to keep the contents warm. Remember the warmer the temperature, the faster the rate of decomposition. We can also place the bin in a sunny area. This is going to have the same effect. It's going to make the compost bin warm and so the decomposers can break down the food quickly. There's also small holes all over and that's going to assure there's a good supply of oxygen. We need oxygen so the decomposers can respires and break down the food. And it will help them multiply and grow so there's even more of them in there. We also want to turn the contents with a fork to avoid the contents becoming compacted. When you turn it over with a big gardening fork that allows lots of oxygen to get in and to make sure any that's at the bottom can get to the top and get a nice supply of oxygen. And also it needs a good supply of water. So we make sure we add water at regular intervals to ensure it remains damp inside the bin. Remember without any water, the decomposers can't survive. So we definitely need to make sure there's some of that. So now a task for you. Many gardeners use compost bins to turn rotting vegetable waste into nutrient rich compost. They are designed to speed up the rate of decay. Compost bins are usually black. Explain why. You need to use as many of the keywords as possible. Go back to our previous slide if you're not sure. The second question is asking, that compost bins will normally have small holes or gaps all over them. You need to explain why. Again, there's key words for you to include. Have a go at writing an answer now. Please pause the video to complete your task and resume once you're finished. Here are the answers. please mark your work. Compost bins are usually black because black absorbs the heat and that keeps the contents inside the bin warm, so the decomposers are more active and it increases the rate of decomposition. Compost bins normally have small holes or gaps and that's cause we need a good supply of oxygen for respiration in the decomposers. And again, that will increase the rate of decomposition. How did you do? Did you include all of those key words? Pause the video so that you can correct your work and make it even better. I know you can do it. Then resume when you're ready to continue. Hopefully you learn from your mistakes from before. So now I want you to have a go at this task. This task is about me, Miss Lewis. Miss Lewis loves having apples at break time, which is true. She brings in a pack on Monday and by Friday they have to be thrown away. Which is also true. What could she do to make her apples last longer? Explain your answers. I would really appreciate some good answers here. I really want to make sure my apples last all the way to the end of the week. So I've started you off with one, for example, she could put it out of the sun because the warmth speeds up the rate of decay. She should also... Please have a go at finishing this task. Put in all the information that you've learnt from this lesson and resume once you finished. Here were the things that I thought I could do to make my apples last longer. Did you get the same? Did you make sure you explained why you said that reason? Pause the video, correct your work. Make sure you've got all the necessary detail in your answer. Well done, you've worked really hard today. There's lots of information there, so well done. So now we can return back to the first question at the beginning of the lesson which I asked you, why does Apple rot? I hope by now you can answer this question. Why don't you have a go at writing down an answer to this question. Include as many key words as possible and show off everything that you've learned in today's lesson. Well done, you've made it to the end. I'm so impressed at how hard you've worked. There was quite a bit of writing at the end there. So you've done really well to make it to this point. Now what you need to do is show off everything you know by completing the exit quiz. Good luck and well done again.

What is decompostion?

What is the role of the detritivores?

Which of the following is an example of a microbe?

Under normal conditions, which factor does not affect the rate of decay?

Which factor is most likely to kill decomposers if it is too high?

How does volume of water affect rate of decomposition?

Why do we wrap our food in cling film?

Which of the following statements best explains the design of a compost bin?

Decay

Explain the design features of a compost bin

This lesson looks at the causes of decay and why it's so important. We then look at the conditions required for decay and how a compost bin is designed to increase the rate of decay.

Science

Y7 Science

Key Stage 3

Year 7

Miss

Ecological relationships and classification

Biology

THEME

UNIT

Food Chains and Webs

Impacts on Food Webs

Random Sampling

Estimating Populations

Classifying Living Organisms

Adaptation

Natural Selection

Evolution Evidence

Case Study of Mary Anning

Biodiversity

Revision (Part 1)

Revision (Part 2)

Which is the correct order of classification?

A curlew is a bird that feeds on small animals which live in mud by the sea. It lays spotted eggs in a nest on the ground. Which adaptation helps the curlew to walk in shallow water?

What is the theory of natural selection?

What is the correct order to describe natural selection?

The theory of evolution states that all life evolved from what?

Tick TWO ways the fossil record provides evidence for evolution.

What is the name of the piece of equipment in the image?

How do you ensure that the quadrat is placed randomly?

The trout, duck, crocodile, water vole and frog are all chordates.  Which of the following is a feature that partly defines these members of the chordate phylum?

The five groups of chordates are:

What is the main difference between mammals and birds?

In what way are amphibians different from reptiles and fish?

Which of the five chordate groups does a bat fall into?

What is the correct definition of interdependence?

Which of the following is an example of interdependence?

What is an abiotic factor?

Which of the following is a biotic factor?

Farmers spray chemicals on crops to kill unwanted weeds. What are these chemicals called?

What are fossils?

What is extinction?

Why are field margins and hedgerows are important in maintaining biodiversity?

This a food chain: Turnip -> Maggots -> Rove Beetle -> Blackbird. Which living organism in the food chain is the primary consumer?

This a food chain: Turnip -> Maggots -> Rove Beetle -> Blackbird. If the population of blackbirds decreased, what would be the effect on the population of rove beetles?

By what process do plants make their own food?

What do the arrows in a food chain show?

The mean number of plants in a 1m x 1m quadrat is 1.5. The lawn measured 12 metres long and 10 metres wide. Estimated the number of plants on the lawn.

Lesson overview:Decay

Ecological relationships and classification: