Hi. It's Mr. Andersen and this AP Biology science practice 7. The first time
I read science practice seven it really didn't make any sense to me. And so let me give you
a reading. And then see what you think. "Science Practice 7: The student is able to connect
and relate knowledge across various scales, concepts and representation in and across
domains." That sounds confusing. But I think what they're really trying to get at is that
they want you to be able to connect knowledge. And so this is da Vinci. And da Vinci had
a lot of different jobs. He was a painter, sculptor, architect, musician, mathematician,
engineer, inventor, anatomist, geologist, botanist, cartographer and writer. In other
words he brought together all of these different disciplines. And that was common back then.
But today we've tended to isolate in each of our different disciplines. If you're a
biologist you really concern yourself just with biology. And that's changing. In other
words, we want you to be able to make these connections and connections of scale. And
what do I mean by scale? We want you to be able to understand how biology works at the
very small scale, at the medium scale and at the very large scale. What's something
at the small scale? That's just going to be molecules. We want you to also be able to
understand scale as far as time span. Time span that is just microseconds all the way
up to geologic time. And also we want you to be able to understand complexity from things
that are very simple to things that are almost infinitely complex, like the human mind. And
so we when we're saying connecting across all of these different scales, if I were to
say this is DNA. DNA is going to be really small. It's not going to be that complex.
It's made up of a few different atoms. And then it's going to operate on a very small
time scale. But they want you to be able to apply that across this whole scale. So if
we're looking at an ecosystem like that, ecosystems evolved over, you know thousands and thousands
of years. They're made up of organisms. Those organisms contain DNA. And so that DNA has
been passed along all the way through this time span. And so we can go from the very
simple to the very complex and they want you to be able to understand that. Or another
example, let's say we have this. This is simply chlorophyll. Chlorophyll is one molecule,
but could you apply how chlorophyll effects everything up to the level of the carbon cycle?
In other words, how plants are taking in carbon. How they're making use of chlorophyll to harness
the power of the sun. And so that's what they mean by senses of scale and making those connections.
And also when they say domains, what they really mean is outside of biology. So thermodynamics
is physics really. But we apply it by understanding that all energy comes from the sun. It's converted
through photosynthesis. And then we make use of that in our food. Or biochemistry. Understanding
how a phospholipid is going to have a hydrophilic head and hydrophobic tail allows us better
to understand at a more complex scale how a cell membrane works. Or if we understand
how diffusion works. Which his essentially chemistry. Then we really can understand how
nutrients, molecules, gasses all these things are moving around inside life. And so connecting
across domains means not only using biology, but chemistry and mathematics as well. And
so at each of the different four big ideas they want you to be able to apply this connection
of all these scales and concepts. And so if we were looking at the peppered moths or natural
selection, to really understand that we have to understand what happened over time. So
we have a change in the time scale. We're really looking at genes. And if we don't understand
genetics we really can't understand evolution. We're looking at free energy. Free energy
and understanding feedback loops is important. But understanding how those different feedback
loops are going to allow organisms to survive in different environments. Or if we're looking
at information. This is a great story. This is the Himalayan rabbit. Himalayan rabbits
are always going to be white except if we have a change in their environment. And so
the temperature in the ears and the nose and the feet cause them to express different genes.
And if you were to put a piece of ice on the back of this rabbit right here, you could
actually shave the rabbit and then change that to have a black patch on the back. And
so that's expressing different genes depending on environmental cues. And that has a lot
to do with the histones that the DNA wraps around. Or if we're looking at cotton. At
the very small scale, understanding how the sugar are built is important. But understanding
how those sugars are attached together to create cellulose gives us a totally different
molecule. It's just like sugar but it's connected in such a way that if you eat cotton it's
not going to be like eating sugar. And so they really only want you to be able to do
two things. They want you to be able to connect phenomena across models of spatial and temporal
scale. Remember spatial is where they are. Temporal is at what time. So here's an example
of a multiple choice question. They're telling you that sickle cell anemia results from point
mutation in a specific gene. It results in a misplaced or a replacement of an amino acid
that has a hydrophilic R group. So which of the following would likely result? And so
you could pause the video and take a stab at this if you want to. Okay you could work
your way through it. So I could eliminate a lot of these. I know were not talking about
DNA structure here or fatty acids. So I know I'm dealing with proteins since we're replacing
an amino acid. So I'm now kind of down to A or D. I could eliminate D because it's saying
the proteins secondary structure is a result of interactions between R groups. And so R
groups remember aren't going to effect us until we get to the tertiary structure of
a protein. So I would choose A as the right answer. They also want you be to able to connect
concepts in and across domains. And so this is one where they're asking you to look at
negative feedback loop in the endocrine system. And so they give four different alternative
correct answers for negative feedback. We could start looking at these across you know,
now we're looking at different forms of anatomy. So here we're looking at, this would be a
nervous response. This is a genetic response. And so I could pare it down to these two which
are going to be related to the endocrine system. And then the only one that's going to have
negative feedback would be B. This would be a positive feedback up here at the top. So
again the questions that they're giving as examples of connecting domains are not super
hard. They just want you to not get stuck in specifics. That it's going to cross several
different domains. And so a good way to get at this is a game that I like to play in my
class. It's called the wiki game. So what you do is you logon to wikipedia. And you
try to make connections between one concept and another. There's some rules, like you
can't use the search box, you can't go outside and do links outside that or visit external
websites. You can't go back. You can't hit back space. You can't click on dates. You
can't use search tools. You can't use like find F. And what you try to do is to get from
concept to concept to concept just going to through and making connections in the links
of wikipedia. And so could you do that? Could you connect from peppered moth, feedback,
cellulose, Himalayan rabbits. I think it took me about 38 links to get from peppered moth
to feedback loops to cellulose and to Himalayan rabbits. Maybe you could do better. You could
put your connections down in the comments down below if you beat my score of 38. But
that's really what we're talking about. We're connecting across different sizes, complexity,
time scale and even domains. And I hope that was helpful.