AP Biology2015-16

How do we attempt to understand a subject as large,

complex, and diverse as Biology?

You should know that, you’re a biology teacher!

Biology is an ever expanding body of knowledge.

Too much to memorize it all…many different fieldsNeed to generalize Create a framework upon which to organize new knowledge Themes are fundamental in understanding the nature of living organisms

We need to get organized, so we look at“Unifying Themes” and “Big Ideas”.

Ten Unifying Themes in Biology

1. Emergent Properties; new, novel properties emerge at each new organizational level as a result of interactions among components at the lower levels.

Recall the levels of biological organization…

Molecules Organelles Cells Tissues Organs Systems Organisms Populations Communities Ecosystems Biosphere

Can a collection of molecules dumped into a test tube do the same things that a cell made of those same molecules can?

New properties emerge as you climb the organizational ladder.

2. Cells; Prokaryotic and Eukaryotic…basic unit of structure and function in all living things.

The Cell Theory

1. All living things are made of cells. (are viruses living?)

2. The cell is the basic unit of structure and function in living things.

3. Cell come only from other cells.(so…ummm…where did the first cell come

from?)

Winner of “Most Dedicated Scientist” Award

Anton van Leeuwenhoek

One day in Delft in the fall of 1677, Antoni van Leeuwenhoek, a cloth merchant who is said to have been the long-haired model for two paintings by Johannes Vermeer—“The Astronomer” and “The Geographer”—abruptly stopped what he was doing with his wife and rushed to his worktable. Cloth was Leeuwenhoek’s business but microscopy his passion. He’d had five children already by his first wife (though four had died in infancy), and fatherhood was not on his mind. “Before six beats of the pulse had intervened,” as he later wrote to the Royal Society of London, Leeuwenhoek was examining his perishable sample through a tiny magnifying glass. Its lens, no bigger than a small raindrop, magnified objects hundreds of times. Leeuwenhoek had made it himself; nobody else had one so powerful. The learned men in London were still trying to verify Leeuwenhoek’s earlier claims that unseen “animalcules” lived by the millions in a single drop of lake water and even in French wine. Now he had something more delicate to report: Human semen contained animalcules too. “Sometimes more than a thousand,” he wrote, “in an amount of material the size of a grain of sand.” Pressing the glass to his eye like a jeweler, Leeuwenhoek watched his own animalcules swim about, lashing their long tails. One imagines sunlight falling through leaded windows on a face lost in contemplation, as in the Vermeers. One feels for his wife.Leeuwenhoek became a bit obsessed after that. Though his tiny peephole gave him privileged access to a never-before-seen microscopic universe, he spent an enormous amount of time looking at spermatozoa, as they’re now called. Oddly enough, it was the milt he squeezed from a cod one day that inspired him to estimate, almost casually, just how many people might live on Earth.

-National Geographic January, 2011

3. Use DNA to pass traits; all life uses the molecule DNA to pass genetic instructions to the next generation.

Look at everyone around you.Think of everyone in this school, then on this planet.Then think of all of the apes, and the dogs, and the fish, and the grass, and the trees, and the plankton, and the coral, and the diatoms, and the bacteria, and the yeast, and the mildews.

Everything is made by putting those A, T, C, and Gs in different orders!

Chimps and bonobos are not your only relatives…you’re distantly related to EVERYTHING!

4. Structure and Function; the form that something takes is related to the job that it does.

5. Interact with the environment; exchange materials and energy with surroundings and other organisms.

The flow of

energy(Think of photosynthesis and cellular respiration)

The Cycling

of Nutrient

s(Water,Carbon,

Nitrogen)

Other organisms are part of your environment!

6. Regulate biological systems; homeostasis maintained by both negative and positive feedback mechanisms.

Regulatory mechanisms ensure a dynamic balance through feedback

7. Diversity and Unity of Life; there are 1.5 million different known types of life, and they’re all related to each other.

How can we tell how closely related two species are?

Which characteristics or traits are important enough to use when grouping living organisms and which ones are not?

Can we use similarities and differences in DNA to determine how closely related organisms are?

How can we show how closely related they are?

Three Domains of Life…

Bacteria, Archaea, Eukarya

Each of the three domains is then broken down into smaller groups with more characteristics in common (or sharing a more and more recent common ancestor.

Kingdom, Phylum, Class, Order, Family, Genus, Species (can breed and produce fertile offspring).

Unity demonstrated by the cilia of members of two different kingdoms of Domain Eukarya

8. Evolution; explains unity and diversity

Unity-

Evolutionary relationships

Connected through a common ancestor

Diversity-

Natural selection

Adaptations in different environments

Darwin and Natural Selection;

The Origin of Species (1859)

1. Heritable variation exists in every population.

2. Individuals struggle and compete for limited resources.

3. Differential reproductive success.

9. Science is a process of inquiry that includes repeatable observations and testable hypotheses

Repeatable observations and testable hypotheses

Typical Sequence of Steps Define problem Search literatureFormulate testable hypothesis Test hypothesis with a controlled

experiment One variable between the “control group” and the

“experimental group”

Record quantitative data Analyze data statisticallyPublish research report

With the College Board’s new emphasis on inquiry, performing the scientific method many times will be a major focus of this course.

Science is a process, not a body of knowledge to memorize. It seeks truth, not to support a particular position. It is cold, objective, and impersonal. It looks at facts and data, and it analyzes the data statistically and mathematically, so no bias or opinion can enter the interpretation of the data. Scientists collaborate and publish results so other scientists can “check their work”. They build on the results of previous scientists and they suggest ways that future scientists can build on their work.

Real science cannot “cheat” or “fudge” results.

Also…your experimental results will never ‘prove’ your hypothesis right or wrong!!!

Hypothesis: Proposed explanationAn educated guess as to the answer for the question

Dependent Variable:Variable measured, counted, or observed in response to the experimental conditions (the measured variable)

Independent Variable:Variable or experimental condition that is manipulated (the variable you change)

Controlled Variable: Variable kept constant

Procedure: Stepwise method

Control Treatment: Independent variable is held at an established level or is omitted

Prediction: “If…Then” statement to test hypothesis

10. Science and Technology are functions of society

Science & technology must function within the framework of society.

Pure vs Applied Science

Consider advances in DNA technology…

-solve crimes

-medicine, gene therapy

-ethical issues

-engineering crops to feed a hungry world more efficiently

-should your insurance company have the right to charge you differently if you have a gene that predisposes you to a potentially expensive-to-treat disease?

Look for and pay attention to these themes as we progress through the year. In this way the bigger concepts and ideas should make more sense and you will gain a deeper, more thorough understanding of life.

In addition to these themes, the AP

Biology curriculum is arranged around 4

“Big Ideas”

Big Idea #1;

The process of evolution drives the diversity and unity of life.

Big Idea #2;

Biological systems utilize free energy and molecular building blocks to grow, to reproduce and to maintain dynamic homeostasis.

Big Idea #3;

Living systems store, retrieve, transmit and respond to information essential to life processes.

Big Idea #4:

Biological systems interact, and these systems and their interactions possess complex properties.

Big Idea #4:

Biological systems interact, and these systems and their interactions possess complex properties.

Big Idea #3;

Living systems store, retrieve, transmit and respond to information essential to life processes.

Big Idea #2;

Biological systems utilize free energy and molecular building blocks to grow, to reproduce and to maintain dynamic homeostasis.

Big Idea #1;

The process of evolution drives the diversity and unity of life.