[00:58.49]CLARE: Hi Jake. How are you getting on with the practical teaching?
[01:03.69]JAKE: It's harder than I expected, but I've got some great classes. How about you?
[01:08.63]CLARE: Not brilliant. I'm really struggling with my Year 12 science class.
[01:13.80]JAKE: Are they hard to control?
[01:15.55]CLARE: Well, I don't have discipline problems as such.
[01:18.79]It's just that they don’t seem to think that science has anything to do with their lives.
[01:23.24]It's depressing.
[01:24.80]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.
[01:32.74]JAKE: Right.
[01:33.73]CLARE: And as part of my teaching practice, I have to design an experiment for them
to do.
[01:39.20]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.
[01:47.25]JAKE: Mmm. Let's think.
[01:49.40]So your methodology would involve the children recording
what they eat.
[01:54.47]OK, 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;
[02:02.87]confidentiality would
be an issue.
[02:05.64]If you could get the right data, the conclusions might be significant,
but I suspect it’s not going to be easy.
[02:13.30]CLARE: Right.
[02:14.34]JAKE: Have you thought about doing an experiment using animals?
[02:17.50]CLARE: Wouldn't that be upsetting for the children?
[02:19.99]JAKE: Well, the animals don't have to be harmed in any way.
[02:24.00]It could just be an
experiment where they're given a certain diet and the effects are observed.
[02:29.72]CLARE: Would I have to get permission to use animals?
[02:32.55]JAKE: Yes, you'd have to submit an outline of the experiment and fill in a form, but it's
quite straightforward.
[02:40.43]CLARE: 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?
[02:48.89]JAKE: No that’s true, but the findings for any experiment are going to be limited.
[02:54.16]It's
inevitable.
[02:55.26]CLARE: I suppose so.
[02:56.99]So what animals could I use to investigate the effects of diet?
Mice?
[03:02.73]JAKE: Yes. You'd need experimental mice - ones that have been specially bred for experiments.
[03:09.81]OK, so what will your experiment be investigating exactly?
[03:14.99]CLARE: Well, something to do with nutrition.
[03:17.86]So maybe we could look at food
supplements... things like extra iron and extra protein, and their impact on
health.
[03:25.22]JAKE: Mmm. That might be rather broad.
[03:28.64]Maybe just look at the effects of one
supplement like sugar, on the health of the mice?
[03:34.49]CLARE: In fact, maybe the focus could be on whether mice can control their own diet.
[03:39.93]JAKE: So what happens when they have access to more sugar, that they don't really
need?
[03:44.68]CLARE: Exactly. Do they eat it or do they decide to leave it?
[03:48.89]JAKE: Great Then later on, you could do a follow-up experiment adding another variable.
[03:55.11]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.
[04:04.94]CLARE: Or I could repeat the experiment but change the type of food I provided ... or
use mice with a different genetic structure.
[04:13.42]But I think your idea would be more interesting, I might think about that some more.
[05:01.29]CLARE: So can I talk through a possible procedure for the experiment where mice are given a sugar supplement?
[05:07.34]JAKE: Sure, I did a similar experiment in college actually.
[05:10.88]CLARE: Great. So how many mice would I need?
[05:14.29]JAKE: I’d say about 12.
[05:16.71]And all young ones, not a mixture of old and young.
[05:20.43]CLARE: OK. And I'd need two groups of equal sizes, so six in each group.
[05:27.09]And how would
I tell them apart?
[05:30.13]I suppose I could put some sort of tag on one group ... or just
mark them in some way?
[05:36.07]JAKE: You could use food colouring, that wouldn't hurt them.
[05:38.91]CLARE: Perfect. Then each group would go into a separate cage, and one group, let’s call
them group A, would be the control group.
[05:48.09]So they'd just have ordinary mouse
food.
[05:50.91]I suppose you can buy that?
[05:52.65]JAKE: Yes, it comes in dry pellets.
[05:54.91]CLARE: And the other group would have the same as the first group, but they'd also have
the extra sugar.
[06:00.21]JAKE: Would you just give them straight sugar?
[06:02.53]CLARE: It might be better to give them something like cereal with it.
[06:06.04]JAKE: Mmm. Then you'd need to weigh the mice, I should think once a week.
[06:10.88]And you'd
need an electronic balance.
[06:13.79]CLARE: But we can’t hold them on the balance, or it'd affect the reading.
[06:17.77]JAKE: Exactly. So you need something called a weighing chamber to stop the mice from running away.
[06:24.17]It sounds complicated, but actually you can just use a plastic box
with holes in the top.
[06:30.38]CLARE: OK. 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.
[06:39.95]And then see
where we go from there.
[06:42.20]That sounds cool I think the students will enjoy it.
[06:46.35]JAKE: Yes. One thing ...
