Hi. It's Mr. Andersen and welcome to AP Biology Science Practice 3. This is
on formulating questions that guide both discussion and further investigations. It used to be
if you were a good scientist it meant that you had a lot of knowledge because there wasn't
a lot of knowledge out there available to everyone. It was housed in libraries. And
even when I was a little kid, if I wanted to find an answer to a question, I literally
had to drive to the library. Get a book. And then look it up in a book. But now since we
have data really available at our fingertips, our ability to formulate and ask good questions
is super important. Especially in the sciences. And I find a transition in my students. Once
they really start to get it, they start to ask higher and higher level questions. And
if you really don't understand it, sometimes you can't even formulate a good question to
ask. And so what kind of questions am I talking about? You should be able to answer questions
when I say, how do we know what we know? In other words I could say, "What scientific
experiments allow us to know that DNA rather than proteins is the genetic material?" And
then you should be able to answer, this is how we know what we know. And so I was trying
to think about how do I get students to get better and better at asking questions? When
do they do that in their lives? And then it came to me that we constantly do that. Because
if you ever type something in Google, you're really asking a question. And so let's look
at a few questions and then we'll kind of judge which ones are good and which ones are
not so good. So let's say you were to type this in. What's the world's smallest living
bird? Well that's an okay question. And Google is going to give you a quick response. I think
it's some form of humming bird. But it's not a great scientific AP Biology question. Because
you quickly get a fact right back to you. It doesn't lead to further discussion or investigation.
Well let's try this one. "Are we alone in the universe?" Well that's a pretty profound
question. If you were to Google that I would imagine you would get lots of answers but
none of them are really going to be right. It's an unanswerable question with the technology
that we have today. So that's not a great question. What about this one. "Are genetically
modified foods good or bad?" Well we're adding value at this point. So what does it mean
to be good? Or what does it mean to be bad? And so that's not really a good scientific
question as well. Once we started adding value to it we can't measure that empirically. So
it's not a great question. Let's go to another one. What about this. "What factors effect
plant growth?" Well now we're getting closer. This is really something that we can measure.
But since I just said factors in there, there's so many things that could effect plant growth.
Number one what type of plant are we really talking about? How will we measuring that
plant growth? And so I could refine that question. What's the optimum carbon dioxide concentration
for brassica rapa growth? And now really I'm paring it down to one independent variable
and then one dependent variable. And so we're getting to a good question that could lead
to fact finding. It could lead to future investigations. And so here's a good example of a question
that AP suggests. "What happens to photosynthesis at vary high non-biological temperatures?"
And so what are we looking at here? We're looking at two things. We've got an independent
variable which is clearly the temperature that we could change. And then we're looking
at a dependent variable which is photosynthesis. And so we do a photosynthesis lab, remember,
where we're looking at the leaf chads float. And so we could change the temperature and
see how that effects it. Before that though we could look at a literature search. We could
actually get through some of the scientific journals and see what, you know, has this
been done before? And what did they find? We could go on a fact finding mission. Google
searches where we find more information and it could lead to experimental design. And
so a good question is going to lead to further discussion and then further investigation.
And they want you to be able to do that in each of the four big ideas. And so here's
some examples they give. So let's say we're looking at evolution. If I were to give you
a phylogenetic tree, you should be able to be able to ask and answer a bunch of questions
based on that. Or what about free energy? You could say, you know, where are the molecules
going to move? This looks like facilitated diffusion. Or we could even pose questions
about, you know, what happens if I change one of these proteins and the function of
a protein? As we get to information there's lots of questions that could be posed about,
you know, genetic problems. So in this pedigree you could try to determine what the inheritance
pattern is. And then we could get even to ethical questions when we're saying if you
know that you have the gene, are you likely to have kids or would you have kids? And then
when we get to systems, interactive systems like, this is a food web. You could ask questions
about, you know, what happens if we change one part of this food web? Or if we were to
decrease the amount of producers, how's that going to effect the consumers? And so you
really have to be able to do three things. You have to be able to come up with questions
or pose questions. You have to be able to refine those questions. And then you have
to be able to evaluate questions that are asked. And you're going to do this on a test
which is asking you questions. And so it's kind of tricky to ask your, to judge your
questioning ability using questions. But this is kind of how they'll get at it. And so first
of all you have to be able to pose scientific questions. And so if I were to give you this,
which is a phylogenetic tree of life. You can see you have the three domains. Eukarya,
Archaea and Bacteria. Could you come up with three good questions that you could answer
either from this tree or from information you know about this tree. So what are some
questions? With each of these remember you can phase the video and take a shot at this.
Well I might ask this question right away. Which of these are more related to eukarya?
Is it the archaea or the bacteria? That would be an okay question. Another question might
be, "What characteristics of archaea and bacteria and eukarya allowed scientists to produce
such a tree?" And then remember this implies that we had one last universal common ancestor
that would be right down here. So what are some shared characteristics of that? And so
those are pretty good questions. Kind of questions at getting how do we know what we know? In
other words how did we come up with a phylogenetic tree like this? The next thing you need to
be able to do is refine questions. So this is a question from a practice test from the
AP College Board that gets at this. And so let me kind of talk you through it. Basically
we have figure 1 up here which shows algal growth of a species in sterilized pond water
over time. So you can see it's increasing and stabilizing. If phosphate is added right
here, then we see the following growth. And so we see an increase in algal growth as well.
And so the question they're asking is, which of the following would be the best prediction
of algal growth if nitrate, rather than phosphate is added? And then they give you four tries
at this. Or four different guesses that you could make. And trust me, when I looked at
this question the first time, I missed this question as well. So take a second to lock
in your answer. And the right question or the right answer is C, right here. Nothing
should happen when you add nitrate. And so when I thought, Oh, I thought this was going
to be it right away. And then as I thought about it a little more deeply, I realized
what we were looking at here is a limiting nutrient. And so basically what happened is
when you added phosphate, that was the one nutrient that these algae were needing. And
so they took off. They didn't need nitrate at this point. So if you would have given
them nitrate, it wouldn't have helped them. Let me put that in context that might help
you. So let's say you're going to the movies. Now I've changed the question. So through
time this is your ability to go watch a movie. If I were to say I gave you your car keys
at point A, we'll say right here. That allowed you to go see the movies. Which of the following
would be the best prediction with, if instead of me giving you car keys, I would have given
you additional money. Well the right answer would be this one, the same one as here. Because
you really didn't need the money to get to the movies. What you needed was to have your
car keys so you could drive to the movies. And so again we're looking at a question that
is then being refined. So they're asking you a question and then you're actually having
to say, let's take that to another level. And finally you have to be able to evaluate
scientific questions. And so this is Stanley Miller. Miller-Urey's famous experiment. They
were attempting to model early earth conditions. Remember they put all of the gases and added
some energy that kind of simulated what early life on our planet was. And we could make
some of the building blocks of life. And so here, in order for them to test your ability
to evaluate scientific questions, they're saying which of these are the questions, or
was the question, that Miller was trying to answer. So you could pause and take a stab
at this one. There right answer is C. He was trying to show that the molecules essential
to life today could have formed under early earth conditions. And so this is how they're
going to get at your ability to ask questions on the AP exam. But questions are very important.
It's almost like dominoes. Because, if you're good at asking questions, that's going to
directly lead to practice 4 which is developing experimentation, then data analysis, then
using explanations and theories. And so the next three science practices are built on
your ability to ask questions. And so I hope that was helpful.