Category Archives: Year 7

Gel electrophoresis

Not much to say this week, just some pretty pictures. It’s a kit supplied by Carolina Biological and our wonderful technician of the year suggested that it would be a suitable activity to include in the new Year 7 Separation topic. It’s an introduction to the concepts of Gel Electrophoresis and it works….

…. well, see what you think! Here’s the set up, with a bit of white card below the tank to help see what’s going on…

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The gel runs in about 15 minutes with a decently powered pack so it fits into a double lesson…

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The protocol separates various dyes and includes 3 unknowns for the students to analyse.

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They absolutely loved it.

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Pressing none of the right buttons

So, last week I made reference to a Year 7 lesson on Animal Behaviour  that I thought people might like to try. Scanning back through previous posts, a kind of retro-burble, I notice that I had already mentioned this in passing as part of a Year 13 lesson. Given that the new A-level specification has completely removed any mention of Animal Behaviour as a Biological topic (why? what were they thinking?!!? absolute madness!!!!) I have simply moved all the wonderful practical activities down to KS3 so that our students get at least some exposure to this fascinating area of Biology.

Which brings us to Skinner Boxes. This follows rather neatly from the work they did with Hettie and Herbie (our hamsters) in their splendid cardboard mazes. After a brief review of the pros and cons of studying behaviour in a laboratory setting, I explain that today they will be working with a brand new animal. Can they guess what it is?

I leave most of the girls in the lab, under the supervisory gaze of our technician, and take two of them (pre-selected) into a neighbouring lab. Here I show them the “Skinner Box”, simply some tables rearranged to enclose a small, square area, with a button-operated bulb on each side (your Physics technician can run up a pair of these in 5 minutes or less). I explain to the two girls that they will be operating the Skinner box. This involves following the instructions on a series of experiments (Skinner box operator instructions 2 Skinner box operator instructions 1 where “rats” (i.e. Year 7 girls) are put, one at a time, into the box and allowed to explore their surroundings. The operators sit outside the box, opposite each other, with a box of Maltesers (to provide suitable rewards), and a long ruler (to provide “punishment”) each.

They quickly grasp what they’re meant to do. I tell them to keep the Maltesers out of sight, under the desk, and to not let anyone else read the instructions. For the first series of experiments, every “rat” will be a sample in Experiment 1 – the “rats” simply have to do is press the button and light up the bulb – if they manage this, they get a Malteser….

I go back next door. Have they guessed the animal yet? Mice! Woodlice! Guinea pigs! Rabbits! No, it’s a much simpler animal. Very basic instincts. Very readily available in a school setting. At this precise moment you are never more than, oooh, 50cm from one…. Oh, is it us? Bingo!

I tell them that they will play the part of experimental rats. That I’m going to take them one by one into my other laboratory and observe their behaviour for 15 seconds. That’s all. They’ve seen how hamsters behave in a strange setting – just pretend you’re a hamster. And I will be filming it all on the department i-pad.

And we’re off. Olivia, the first “rat” in, provides a textbook example.  She snuffles around inquisitively and, with seeming inevitability, presses a button. Flora (one of the Skinner Box operatives) dutifully delivers a Malteser. Olivia giggles with surprise and delight and immediately presses the button again. Voila! Another Malteser is provided. I quickly stop her because I don’t want the Maltesers to run out – she’s got the idea, she’s learned the association.

Experimental rats get to watch the other rats being tested – it’s partly the logistical difficulties of having yet another holding area, but mainly because I want them to see and enjoy what’s going on.

At this point, something rather surprising happens. The next 5 girls do nothing – literally, nothing. They stand there, all self-conscious and slightly giggly, some not even looking around, but absolutely refusing to risk doing anything in case it’s wrong. “What am I supposed to do?” some of them mouth at the other girls, but they are under strict instructions not to give any clues, and after 15 seconds I put them out of their misery (i.e. I stop the experiment – I don’t put them down humanely!).

Sofia, rat number 7, behaves just like Olivia (hurrah!) and then, joy of joy, in steps Maria who just decides that she will spend her 15 seconds spinning like a whirling dervish, her long blonde pony tail whirling behind her. “I’m dizzy….” she gurgles delightedly as she staggers out of the test area. By now, of course, every girl in the room now realises that they should have done and while feeling rather foolish and frustrated, they’re also enjoying seeing others miss the point.

By the end, only 5 out of 20 girls were sufficiently curious and lacking in anxiety to win some Maltesers. The rest just didn’t want to risk doing anything in case it turned out to be wrong, whatever that might mean. Where does this fear come from? Our education system? Our nationality? Can we blame Michael Gove? Whatever the reason, it makes for a good life lesson. Take a chance! Just do it! What’s the worst thing that can happen? You might win a Malteser!

Of course, having now all seen the kind of thing that’s going on, they’re all suitably prepped for the second round of experiments. This time I let everyone watch, because all the experiments are different. And now they are wonderfully imaginative and creative in their quest to get the right behaviour pattern. I particularly like the girl who just stands in the middle of the box and says, very quietly and politely, “Please can I have a Malteser?” Some girls find they are being prodded by a ruler – which continues until they press the button. And so on.

It makes for terrific discussion. How is this different to the maggot behaviour? Which is better for learning, reward or punishment? Should you revise with chocolate or electric shocks? And where are the real life examples of this kind of learning? This last takes them a while, but they eventually come up with learning what stinging nettles look like (could be a good comparison to start the exercise – demo lots of different leaves – which ones do they know), and the warning colours of bees and wasps.

Learning about Learning by doing – the only type there is.

And that’s nearly yer lot for this year. I’ll post one more burble next Wednesday, and then it’s the summer holidays. I, for one, can’t wait.

The hamsters are amazed

My Year 7s return from a week long residential in deepest Somerset to start the final topic in their completely re-written Year 7 KS3 Scheme of Work. I’m quite excited about this, but also slightly nervous. As always with a new idea, there’s the lurking anxiety, will it work?

It’s Biology’s turn and I’ve decided to chuck out the flowering plants. They get to do this in Year 9 as part of their iGCSE and, frankly, you can have too much of a good thing. Plus, while there are fun things to do with pollen grains/tubes and dead nettle dissection and trying to address the whole bizarre concept that flowers are SEX ORGANS and that, yes, plants HAVE SEX, and hay fever is caused by… but let’s not go there…. it’s not really a topic that lends itself to investigative experimental question asking. It’s much more from the “here-are-lots-of-strange-words-and-weird-structures-and-you-need-to-learn-them-for-the-exam” school of information delivery, a throw-back to the days when all science really was just Physics or stamp collecting. Biology has moved on from just describing stuff; so should we.

So I’ve turned to an area very close to my heart, one I did my PhD in, and one that has been brutally stripped from the new A-levels – Animal Behaviour. After all, it they’re not going to study it anywhere else, they can do it in Year 7. Plus, cunning laugh, it allows me to put my baboon behaviour resource firmly into the Year 7 curriculum. More on that in a future burble. Today was just the introduction, and it’s back to the hamsters.

Quick review with accompanying pictures:Introduction to hamsters with notes

What’s this?       A hamster!

Where does it live? In the desert! The Syrian desert!

What’s it like in the desert, the Syrian desert? Hot, cold, dry, exposed, sparse food.

How on earth does a hamster survive in such an extreme place?

They’re very good at this. Lots of good ideas on camouflage and burrowing and cheek pouches and being nocturnal, having good sense of smell and so on. Excellent. They are children of Attenborough. Let’s focus on the behavioural adaptations.

I get them to sit in a closed circle, on their knees, no gaps. I then plonk the docile furry bean bag that is Herbie the hamster into the circle. I tell them to watch what he does. How is this behaviour helpful for surviving in the desert?

It works really well. They love seeing Herbie, they all get a chance to stroke him as he goes round, and they’re perceptive. Herbie is exploring, Herbie is sniffling, Herbie likes tunnelling into gaps. This all makes sense. What else? It’s so obvious that it takes them a while to see it, but eventually they do – Herbie sticks to the edges – he never ventures out into the middle. Again, they instantly see why this makes sense for a small, edible organism foraging in an exposed environment.

So that’s the introduction. We’re going to be investigating animal behaviour and why animals do what they do – how does it help them survive?

I then introduce the idea of mazes. Can they think why it’s easier to investigate behaviour in a laboratory setting? Brief discussion on this, as I want them to get started on their project. Right, here are the kind of questions you can ask with mazes.

In groups of 4, I tell them to decide on a question – one of the ones I’ve suggested, or one of their own, and then build a maze to test it. They are VERY happy with this! Year 7s, cardboard, scissors, sellotape, the chance to make something and then put a hamster into it…. I haven’t seen them this happy since they made apple juice in the autumn term.  They’re off and running.

Of course, being Year 7s, the excitement of maze building might distract them from the scientific question I want them to ask. Sure enough, a couple of the groups haven’t quite thought it through. There’s some nice ideas about hamsters and smell, and hamsters in the dark vs hamsters in the light, but they’ve not narrowed it down to a simple, testable hypothesis. It’s the price you pay for being open ended. I like the excitement and motivation that ownership of the project gives the girls, and they can generate some superbly original ideas, but they will need quite a lot of support along the way. It’s important to keep circulating, to keep talking, to keep asking them questions.

We talk about some of the options. How could they improve this? What are they going to measure? They start to become more focussed. The other groups are fine – they really seem to have grasped the idea of simple, controlled experiments. How on earth is this possible???? They haven’t written anything down all year!!!! So, do hamsters get quicker at finding their way through a maze – this group is building a magnificently complicated maze, know exactly what they’re doing and have taken on board ideas of repeats and controls. Wonderful. Another group is testing food preferences and is building an appropriately simple T-maze. A third is seeing if turns are made at random, or whether there’s a pattern – does turning left make the hamster more likely to turn right next time. Excellent.

Best of all, and one of my Key Performance Indicators (aarrrghhhh) of a successful lesson, they all look surprised and rather disappointed when I tell them it’s time to clear up. Is that really the end of the lesson? How has it gone so quickly?

The actual experiments take place on Friday….

The Lesson from the Black Lagoon….

As I’ve mentioned in previous burbles, one of my main projects this year has been to overhaul the KS3 scheme of work for the Year 7s (next year I hope to tackle the Year 8s). This has been a mammoth undertaking, far more work than I had originally envisaged, but has also been a huge amount of fun; I’ve loved teaching Year 7s for the first time in my career, and I’ve loved the creative aspect of creating new lesson plans and resources. Because KS3 Science is standardised across the year groups, it’s also been my cunning way of ensuring that this investigative approach is used by other teachers…

But at this time of year, with 6th form rapidly approaching study leave and PSAs to deliver, mark and moderate, and all kinds of other time consuming priorities, I had decided to leave any updating of the Element and Compounds topic until next year. And then I saw the first lesson on the olde scheme of work…

“Give out the packs with the periodic tables: discuss the periodic table and elements – what they represent and a basic idea of how they’re organised. Make sure students write down the definition of an element.”

… and I thought, I’m not doing that. No way. I can’t imagine a worse way of doing this. Sure, they have the information. They’ve written something down. But having a pack of information, writing something down, is not the same as knowing something. And knowing something is not the same as understanding it. And, worst of all, however you dress it up, it’s just dull dull dull. The lesson from the black lagoon.

So we did this.

After an introductory practical “circus” of elements and their properties, which I hadn’t changed from the original SoW, and which they got very excited about, (especially when they got to test the gas jar for the presence of oxygen to see whether the label was accurate, or whether I was lying), I talked a little bit about the history of elemental discovery. All these elements! All these properties!

Then I gave each pair one of these with some scissors

Periodic table cards for working it out a la Mendeleyev

a set of the first 20 element cards in the order that they were discovered. The cards had the atomic number (which I just called “weight”), the valency, and a brief description of the properties. They had to cut them out and try various ways of arranging the cards to see if anything interesting emerged. They were not allowed to do any research – they were not allowed to look at the Periodic Table in their planners. This prompted lots of good questions – what is valency? What do I mean by “weight”? And so on.

At this point it got quite full on. Some put them into piles based on their state of matter. But this didn’t really show anything interesting. What else could they do? Don’t put them into piles, for a start. Arrange all the cards face up and visible on the desk. They tried grouping them by valency, and although that saw the Noble Gases pop out in a nice, distinct collection, it also saw Sodium in with Chlorine. Not helpful. What else could they do? What would be the simplest thing to do?

I was rushing from group to group thinking, next time, they’ll do it in 4s, not pairs!

But then they started to crack it. They starting putting them in order of weight and, joy of joys, they started seeing it. And they got VERY excited. Look! These ones have all the same properties! And so do these! And these! Look! The valency goes 0, 1, 2, 3, 4, 3, 2, 1….

What’s going on????? It was one of those glorious, eureka moments that make teaching better than any other job on the planet.

At this point I talked about Mendeleev. How he had an element named after him. How he transformed our understanding of Chemistry. How he was a genius. And how they had just done exactly what he did.

And there was something else he did, too.

I then handed out these

Periodic Table with gaps for predicting properties

Periodic Tables with 3 elements blanked out. Tell me about these elements, I said. You don’t know what they are, you’ve probably never heard of them, but you can still tell me something about them. At first they weren’t quite sure what I meant. Did I want them to find out the names? No, I don’t want you to do any research. I don’t want you to find out anything. Just tell me something about those elements.

And then they twigged. Element number 1, must be a soft metal that reacts readily with water and has a valency of 1. Element number 2 must be a coloured, poisonous gas with a valency of 1. Element number 3 must be a colourless, odourless, completely unreactive gas with a valency of 0. Bingo! Meet rubidium, bromine and krypton.

There are things I’ll change the next time I do it, but as an exercise, it works. They figure it out, they understand it, they can use it to make predictions… next time, we might write some of it down…

Bupples and Benedicts

Back to burbles of a strictly biological nature this week, and a recent idea that passed quality control with Year 7.

So, what do you think of Benedict’s Test for reducing sugars?

To be honest, I’ve always regarded it a pretty boring part of any Biology course. Oh, it’s wonderfully colourful, and the students always enjoy the chance to get out the Bunsen burners, but given the intoxicating wealth of mind-boggling Biology available to anyone tasked with writing a specification, it’s odd that it repeatedly survives the cut, while Immunology (to take just one example) gets repeatedly hacked to the bone and beyond.

Now, one of my main projects this year is to completely re-write the Year 7 Scheme of Work. I want to move away from a course where factual material is delivered in vast, turgid chunks, to lessons that encourage curiosity about the natural world, asking interesting questions and answering them through experimental investigation – you know, something a bit like Science. As far as possible, as with all my teaching, I want them to find things out for themselves.

Being a general science course, I spent the autumn term working on Chemistry (Purification) and Physics (Energy) which has been a lot of fun, and I’ve learned loads as these are both well outside my area of expertise (particularly Physics, which I gave up when I was 14). But now we’re finally on to the first Biology topic and I’m feeling a lot more zonally comfortable. The theme is Cells and Human Reproduction and I’m basing it largely on apples and hamsters. Wonderful things, apples….

So, opening lesson, do they like apples? They nearly all do. Why? Because they’re crunchy! Well, lots of things are crunchy (bricks, gravel, celery, cockroaches) – there must be something else going on. Because they’re sweet! Aha, why are they sweet? Because they contain sugar! Good hypothesis! But how do you know? Ermmm….because sugar is sweet? Maybe, but lots of things might make something sweet, how do they know that it’s specifically sugar that makes apples sweet? Blank looks.

Right, working in pairs, they have 4 small beakers, one of sugar (glucose), one of distilled water, one of apple juice, and one with a mysterious blue liquid. Pausing only to demonstrate safe use of a simple water bath, I tell them to use the above to prove that apple juice contains sugar.

The blue liquid is, of course, Benedict’s reagent, but they don’t need to know that. And I deliberately don’t tell them that it’s a test for sugar, otherwise the whole learning outcome of the lesson is negated. What are they going to do?

I’ve praised curiosity and the value of testing ideas empirically since September, so they’re very happy to try lots of things. Again, it’s one of those lessons where you’ve got to be quite hands on, moving quickly between the pairs to hear their ideas and head the more ridiculous ones off at the pass. Some of them think they should separate the sugar from the apple juice by evaporation (echoes of the Purification topic) so I point out that I haven’t provided an evaporating dish – the water bath is for heating. Plus even if they did this, how would they know that the separated powder was sugar?

Many of them just shovel all the ingredients into a test tube and heat it. Oh the excitement! It goes brick red! Wow! Fantastic! Well done! What does that show? Ermmmm…. And at this point they really start to think.

So they heat the blue liquid with apple juice. It goes brick red! What does that show? Ermmmm….

So they heat the blue liquid on its own. Good. What explanation are you eliminating? Still doesn’t show its sugar, of course….

So they heat the blue liquid with sugar. And so on.

Nobody’s mentioned controls, fair tests, but they demonstrate that Ben Goldacre is absolutely right – children intuitively understand the principles of a scientific experiment.

By the end of the lesson, they’ve taught themselves Benedict’s test and, based on the follow up homework which I’ve just finished marking, the vast majority understand the importance of eliminating other possible explanations with controls. And they feel really pleased with themselves because they’ve done it all themselves. Better still, in the next lesson, they can all recall what they did and why they did it.

More on apples to follow – they are a fabulous biological teaching tool!

Have a good week.

Post Burble

Why bupples in the title…? It’s how my eldest son pronounced “apple” when he was 2 years old. I encourage my students to do the same.