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Hi. It's Mr. Andersen and welcome to AP Biology Lab 11. This one is on animal behavior. And
the animal that we'll be studying most of the time is something called a pill bug. And
pill bug is, looks like this. They're found underneath rocks. You lift it up and they
kind of scramble. I used to call them rolly pollies when I was little. And since we're
studying animals, we're now entered into the area called ethology which is the study of
animal behavior. And animals tend to show two different responses in response to stimuli.
The first and simplest is called kinesis. Kinesis is basically, and it comes from kinetic
or movement, it's when organisms are moving around quickly when they're unhappy. And then
they move slow when they're happy. And so pill bugs are going show this. If you lift
up a rock, they're going to run crazily. But if you put the rock down then they're going
to be happy. And then they're going to slow down. And you might think that's a real simple
form of behavior. But simple is great. Because you don't need too many neurons to do that.
You can make a pretty simple brain that can respond in this way. Imagine programming a
robot that would simply run really quickly if it's unhappy. Let's say there's light.
And then stop moving when it's not. Now way more difficult way to kind of program that
kind of robot would be through taxis. Taxis is when they see something. Respond specifically
to that. So if they're moving towards an odor or towards light or away from light or things
like that, that directional response is going to be harder to program. It's going to contain
a more of a brain. But it's also more sophisticated. So you searching out a hamburger is clearly
taxis. Okay. So in this lab there are two parts to it. First of all we have to watch
fruit flies court. In other words fruit flies are going to go through a courtship ritual
to make sure that it's of the same species and of the opposite gender. Now humans undergo
courtship as well. In this picture it might be reciting poetry or singing a song. Or wearing
the correct type of bonnet. But in fruit flies it's going to be quite a bit different than
that. There will be singing. There will be dancing. There will be licking. There will
be finally be copulating. But all of it is designed to set up behavior that insures the
safety and successful mating of both of the fruit flies. And so if you watch fruit flies
for awhile you're going to be able to pick up, especially those that are courting, some
of these specific types of courtship behaviors. Most of the lab though however is studying
the behavior or the kinesis of pill bugs. So basically what you do is you take 5 pill
bugs. And you're going to put them on this side. Now this is a petri dish. It's got a
cover on it. But on this side it's going to be moist. So we've got paper towel on the
bottom but it's going to be moist. On this side it's going to be dry. So we're going
to put 5 over here. And then we're simply going to start the clock. And then we're going
to watch them. So we watch them for maybe ten minutes. Every 30 seconds we count the
number on either side. And so let me tell you what would happen. Well they don't like
it where it's dry. So they're going to bounce over here. They're going to bounce over here.
They're going to bounce over here. These ones are going to be moving really really quickly.
And eventually they may make their way over to here. These ones are really happy. So they're
going to go really slow. And so pretty soon instead of having 5 on this side and 5 on
this side, you might have 6 on this side and 4 on this side. Or you might have 7 on this
side and 3 on this side. And so basically what you can do is you can record how many
are on either side at each of those time intervals. And so we can start to piece together if they're
happy or not. Or where they're happy or not. So here are some results from a video. Basically
at time 0 you can see that we had 5 on each side. But then it quickly went on the wet
side to 10 and 0 on the other side. And there's movement all along but we could do a histogram
of this, so we could do a bar graph. And we could see that the average, they're spending
more time on the wet then they are one the dry. But that's about all I can say. In other
words if I don't do statistical analysis, if I don't do chi-squared analysis, then I
can't tell much from that. And so basically if you don't understand chi-squared analysis,
take a look at that video. Because in that video I'm also going to show you the pill
bugs moving and you'll be able to calculate the chi-squared value and show are they really
choosing the wet over the dry or not. And so that's animal behavior. And I hope that's
helpful.