| Hi Jake. |
| How are you getting on with the practical teaching? |
| Ah... it's harder than I expected, but I've got some great classes. |
| How about you? |
| Not brilliant. |
| I'm really struggling with my Year 12 science class. |
| Are they hard to control? |
| Well, I don't have discipline problems as such. |
| It's just that they don't seem to think that science has anything to do with their lives. |
| It's depressing. |
| They listen to what I say, |
| and I gave them a test last week and the results weren't too bad, |
| but there's no real engagement. |
| Right. |
| And as part of my teaching practice, I have to design an experiment for them to do. |
| I was wondering about something on the children's diets... |
| You know, asking them to record what they eat and maybe linking it to their state of health. |
| Mmm. Let's think. |
| So your methodology would involve the children recording what they eat. |
| Okay, but you'd also need to have access to the children's medical records |
| and I don't think people would be happy about that; |
| confidentiality would be an issue. |
| If you could get the right data, the conclusions might be significant, |
| but I suspect it's not going to be easy. |
| Right. |
| Have you thought about doing an experiment using animals? |
| Wouldn't that be upsetting for the children? |
| Well, the animals don't have to be harmed in any way. |
| It could just be an experiment where they're given a certain diet and the effects are observed. |
| Would I have to get permission to use animals? |
| Yes, you'd have to submit an outline of the experiment and fill in a form, |
| but it's quite straightforward. |
| But if we found out that, say, a particular diet affects the health of animals, |
| the same thing wouldn't necessarily be true for people, would it? |
| No, that's true, |
| but the findings for any experiment are going to be limited. |
| It's inevitable. |
| I suppose so. |
| So what animals could I use to investigate the effects of diet? |
| Mice? |
| Yes. |
| You'd need experimental mice - ones that have been specially bred for experiments. |
| Okay, so what will your experiment be investigating exactly? |
| Well, something to do with nutrition. |
| So maybe we could look at food supplements... |
| Things like extra iron and extra protein, and their impact on health. |
| Mmm. That might be rather broad. |
| Maybe just look at the effects of one supplement, like sugar, on the health of the mice? |
| In fact, maybe the focus could be on whether mice can control their own diet. |
| So, what happens when they have access to more sugar that they don't really need? |
| Exactly. |
| Do they eat it or do they decide to leave it? |
| Great. |
| Then later on, you could do a follow-up experiment adding another variable. |
| Like, you could give some of the mice the chance to be more active, |
| running on a wheel or something, |
| and the others just sit around and don't do much. |
| Or I could repeat the experiment but change the type of food I provided... |
| or use mice with a different genetic structure. |
| But I think your idea would be more interesting, |
| I might think about that some more. |
| So can I talk through a possible procedure for the experiment where mice are given a sugar supplement? |
| Sure. |
| I did a similar experiment in college actually. |
| Great. |
| So how many mice would I need? |
| I'd say about 12. |
| And all young ones, not a mixture of old and young. |
| Okay. |
| And I'd need two groups of equal sizes, so six in each group. |
| And how would I tell them apart? |
| I suppose I could put some sort of tag on one group... or just mark them in some way? |
| You could use food colouring, that wouldn't hurt them. |
| Perfect. |
| Then each group would go into a separate cage, |
| and one group, let's call them group A, would be the control group. |
| So they'd just have ordinary mouse food. |
| I suppose you can buy that? |
| Yes, it comes in dry pellets. |
| And the other group would have the same as the first group, |
| but they'd also have the extra sugar. |
| Would you just give them straight sugar? |
| It might be better to give them something like cereal with it. |
| Mmm. Then you'd need to weigh the mice, I should think once a week. |
| And you'd need an electronic balance. |
| But we can't hold them on the balance, or it'd affect the reading. |
| Exactly. |
| So you need something called a weighing chamber to stop the mice from running away. |
| It sounds complicated, but actually you can just use a plastic box with holes in the top. |
| Okay. |
| So once we've measured the weight gain of each mouse |
| we can work out the average for each group, as well as the standard deviation. |
| And then see where we go from there. |
| That sounds cool! |
| I think the students will enjoy it. |
| Yes. One thing... |