Intro to Biology Purpose: to introduce the recurring themes of this course and describe the mechanisms by which science is explored

Types of Science:

What is Science???  S tudy of a topic that seeks to understand and explain the universe around us. Often requires experimentation and must be supported by evidence

How do scientists test an idea and set up an experiment?

Scientific Method  Observe and Identify Problem  State hypothesis  Design an experiment  Record data  Analyze data and form a conclusion Experiment must be repeated many times!

You notice something (Observation) It makes you wonder, why? Or How? (Ask a Question/State your Problem) You think about it for a while. Based on the knowledge you have, you think you have an idea, but aren’t sure (Form a Hypothesis) You decide to test out your idea (Experiment) Does it look like your hypothesis was right? Support of Hypothesis After many repetitions of the tests by you and other “observers”, all of which continue to support your hypothesis (Repeat Experiment/Publish) Hypothesis becomes a Theory You look at the results of your tests. (Data analysis/ Conclusion) Or do your results suggest something else? Scientific Method New Hypothesis

What is the difference between an observation and an inference? Give an example:

Types of Data Quantitative Numeric Give an example: Qualitative Description Give an example:

What do experiments need?  Types of Variables: Dependent (output): what you measure; data you collect; your results (D is for DATA!!) Independent/experimental (input): the specific factor you are testing; will be different in each set up and missing in the control

Easy to identify variables  Take every experiment and phrase it as follows:  We are testing the effect of _________ on _____________. The first blank is the independent variable and the second is the dependent.

What else does an experiment need?  Control (control group): test subject that doesn’t receive experimental treatment; used for comparison;  Constants (controlled variables): characteristics of the experiment that remain the same between test subjects

Key Terms:  Sample Size: number of subjects that you run your experiment on  Sampling Error: error that arises from testing too few subjects

 Example experiment: You want to determine what the optimal amount of water is for plants. You set up 4 identical corn plants and give them each different amounts of water over two weeks.  Plant 1: no water  Plant 2: ½ liter  Plant 3: 1 liter  Plant 4: 1.5 liter  Collect data, draw a conclusion

 Which plant is the control?  What is the sample size?  What is the dependent variable?  What is the independent or experimental variable?  What are some constants?  Why is the control important?

What is the difference between your data and your conclusion?? Observation vs. interpretation Data: the plant that got the most water grew the tallest Conclusion: Water helps plants grow tall.

How is a theory different?

 A theory is the most rational explanation for a phenomenon based on CURRENT data and evidence. Agreed upon by majority Can a theory change??

Biology: study of living things how they work how they interact with the environment how they change over time Included in this is are many specific areas of study such as medicine, nutrition, genetics, physiology, microbiology, ecology, environmental studies, evolution and biochemistry (just to name a few).

Living vs. Non-living  Two main components of the environment. Abiotic-  Examples? Biotic –  Examples?

ENERGY IS A BIG DEAL  Living things must obtain nutrients and energy  Why do we need to do this?

Chemistry explains what life is made of!  We are made of matter - anything that has mass (takes up space no matter how small).  We use Energy to do work – Energy isn’t matter, however we can get it from matter  All the matter is made up of tiny particles called atoms

WHAT REALLY MATTERS FOR LIFE???  Only a few types of atoms (called elements) are used to make up most of a living thing CHONPS are the major ones!  These atoms are not yours alone! They have been shared with the environment and other living things!

How do we share? These major atoms are recycled constantly

So certain elements can cycle between abiotic and biotic factors!

Other important Abiotic factors  What other cycle do you know? Hint: this factor is essential for life!!!

Other important Abiotic factors  Soil: primarily made of decomposed living things  Earth/rock: fits into geology, but essential to formation and structure of our planet Even rocks cycle. How??

In other words, the same types of atoms can be combined differently to make both living and non-living things!

What is life?  There is a lot of Diversity in life, what do they all have in common??

Do Now:  List something that is living and is an animal.  List something that is living and is a plant.  List something that is living and is not a plant or an animal.  What characteristics do they have in common? What are the differences?

Requirements to be alive!  Must be made of one or more cell  Must Reproduce  Grow and develop/ synthesize  Use energy Where does energy come from?

Requirements to be alive!!  Must metabolize: Take in/produce food and perform chemical reactions to transform the energy in food into a useable form called ATP Metabolism: sum of all chemical processes

Requirements to be alive!  Must respond to stimuli (changes in environment) to maintain homeostasis Examples:

Homeostasis  Constant internal environment

Homeostasis:  Maintain internal body temperature  Excretion of waste  Other examples:

Requirements to be alive!  Must evolve (change) over time Refers to species, not an individual

Are there exceptions?  Consider these: Viruses: not made of cells, but can infect cells and use their machinery to reproduce

Are there exceptions?  Consider these: Mules: made of cells, but can not reproduce

Are there exceptions?  Consider these: Fire: not made of cells, but metabolizes, grows, reproduces?

If all living organisms share these characteristics, why are they different?

Taxonomy  Classification and naming of living things based on similarities and differences

Modern Linnaean System  Domain  Kingdom  Phylum  Class  Order  Family  Genus  Species

Binomial Nomenclature  Living organisms are scientifically named by their genus and species Ex. Homo sapiens

Classification  Organisms that are more similar (closer related) will be in more of the same classification categories Ex: Which are closer related, dogs and pigs or dogs and trees?

6 Kingdoms 1. Archeabacteria 2. Eubacteria 3. Protista 4. Fungi 5. Plantae 6. Animalia