Student Biography What was your last science/math class? What was your grade? What is your strongest and weakest subjects? Do you have access to a home computer? What are your hobbies/interests? Do you have a job after school? What type of career are you interested in pursuing?

The Science of Biology

What is Science?? The goal of science is to investigate and understand nature, to explain events in nature, and to use those explanations to make useful predictions

Science-an organized way of using evidence to learn about the natural world Biology-science that seeks to understand the living world The study of life!

Scientific Method

Steps in the Scientific Method Observation Observation Hypothesis Hypothesis Experiment Experiment Data Collection Data Collection Conclusion Conclusion Retest Retest

Observations Gathered through your senses Gathered through your senses A scientist notices something in their natural world A scientist notices something in their natural world

Observations An example of an observation might be noticing that many salamanders near a pond have curved, not straight, tails An example of an observation might be noticing that many salamanders near a pond have curved, not straight, tails

Observation Activity Get with a partner. SECRETLY choose an object in the room. Write down everything that you observe about this object, while sitting in your seats. Be quiet—you don’t want your neighbors to hear.

Observations Two types Quantitative characteristics that are measured or counted Mass, volume, temperature (anything that is expressed as a number!) Qualitative descriptions of phenomenon that can include sights, sounds, and smells

Peridontal bacteria You have all heard of plaque, the nasty stuff that forms a film on your teeth, but I bet you never knew it looked like this! A photomicrograph of colonies of the bacteria that form, it was taken as they grew in an agar dish.

Moth scales Did you know that butterflies and moths get their color from scales? They do, and these are the scales of the endangered Madagascan moon moth. Scanning electron micrographs are black and white and then colored. Here, the color is light green, which is the natural color of the moth.

African Elephants Aerial View

Observations lead to questions… You then need to have potential answers for your questions

Forming a Hypothesis Scientists use observations and data to form a hypothesis—a proposed answer for a scientific question Must be specific and testable!

Hypothesis A suggested solution to the problem. A suggested solution to the problem. Must be testable Must be testable Sometimes written as If…Then… statements Sometimes written as If…Then… statements Predicts an outcome Predicts an outcome

Hypothesis An example of a hypothesis might be that the salamanders have curved tails due to a pollutant in the moist soil where they live. An example of a hypothesis might be that the salamanders have curved tails due to a pollutant in the moist soil where they live.

Write a Hypothesis to explain the Situation 1. Suppose you observed an ant carrying a grain of sugar to an anthill. Soon after, you saw hundreds of ants moving to the spot where the first ant had found the sugar. a. What is the question you asked yourself from this observation? b. Give a hypothesis to explain how it communicated.

2. A student places a jar of fresh, clear pond water on a sunny windowsill. A week later, the student notices that the water has turned green. a. What is the question you asked yourself from this observation? b. What hypothesis would explain this change?

3. A person that you work with everyday is standing near you. Suddenly you notice that they have noticeably white teeth. a. What is the question you asked yourself from this observation? b. Give a hypothesis to this situation.

4. After looking at the Greenwood High School football program, you notice that 12 of the returning players are much heavier than they were the previous year. a. What is the question you asked yourself from this observation? b. Give a hypothesis that could explain this increase.

5. Several women in a small rural town in Virginia have given birth to children with unusual birth defects. Although the defects are different, it is a high percentage of the population that is affected. a. What is the question you asked yourself from this observation? b. Give a hypothesis to this situation.

6. A new breed of five toed frogs is discovered in a lake near Minnesota. They have never been seen before but possess characteristics similar to some species 300 miles away. a. What is the question you asked yourself from this observation? b. Give a hypothesis to this situation.

Using the Scientific Method Decide exactly what the question or problem is, and state it clearly in words. Study all the facts to see how they relate to the problem. Formulate various hypotheses. Design your experiment. Conduct the experiment to gather data and make observations.

Experiment A procedure to test the hypothesis. A procedure to test the hypothesis.

Experiment Variable – factor in the experiment that is being tested

Experiment A good or “valid” experiment will only have ONE variable!

Controls and Variables

Scientific Experiments Follow Rules An experimenter changes one factor and observes or measures what happens.

The Control Variable The experimenter makes a special effort to keep other factors constant so that they will not effect the outcome. The experimenter makes a special effort to keep other factors constant so that they will not effect the outcome. Those factors are called control variables. Those factors are called control variables.

What is the Purpose of a Control? Controls are NOT being tested Controls are used for COMPARISON

Other Variables The factor that is changed is known as the independent variable. The factor that is measured or observed is called the dependent variable.

Example of Controls & Variables For example, suppose you want to figure out the fastest route to walk home from school. You will try several different routes and time how long it takes you to get home by each one. Since you are only interested in finding a route that is fastest for you, you will do the walking yourself.

What are the Variables in Your Experiment? Varying the route is the independent variable Varying the route is the independent variable The time it takes is the dependent variable The time it takes is the dependent variable Keeping the same walker throughout makes the walker a control variable. Keeping the same walker throughout makes the walker a control variable.

One more thing… it is best to make several trials with each independent variable.

Valid Experiments

Remember: To be a Valid Experiment: Two groups are required --- the control & experimental groups There should be only one variable

Data Results of the experiment May be quantitative (numbers) or qualitative

Data Must be organized Can be organized into charts, tables, or graphs

Conclusion The answer to the hypothesis based on the data obtained from the experiment

Retest In order to verify the results, experiments must be retested.

Review

Solving a Problem 1)Identify a Problem 2) State Observations about the problem 3) Form a Hypothesis about the problem (if…then…) 4) Design an Experiment to test the hypothesis 5) Collect Data 6) Form a Conclusion 7) Retest