1.1 Introduction to Biology The Study of Life 1.1 Introduction to Biology 1.2 The Nature of Science 1.3 Methods of Science

What is Biology? Biology: the science of life Biologists Study the diversity of life Research diseases Develop technologies Improve agriculture Preserve the environment

All Living Things…. Are made of one or more cells Are organized Grow and develop Reproduce Respond to stimuli Require energy Maintain homeostasis Evolve over time

Levels of Organization in Living Things Molecules ↓ Cells Tissues Organs Systems Organisms Populations (members of the same species) Communities (members of several species) Ecosystems (living and non-living elements) Biosphere

What is Science? Science: the body of knowledge based on the study of nature (biology, chemistry, physics, Earth science) How is science different than your other classes? In science class we will: Relies on evidence Explain scientific knowledge Challenge accepted theories Question results Test Claims Use peer review Use the metric system

Comprehension Check What is the difference between an inference and an observation? Why should scientists be observant, curious, skeptical, and open-minded?

How does science work? Science follows a process (sometimes called the scientific method): Ask a Question Observations: collected with your senses Inferences: made with your mind http://www.youtube.com/watch?v=A3l-0sAiMVA Form a hypothesis A testable explanation of a situation Collect Data Controlled Experiments have control and experimental groups Independent Dependent Variables Constants Data: Quantitative (numbers) and Qualitative (descriptions) Analyze Data Graphs and Charts Report Conclusions

Comprehension Check Identify if the following are qualitative or quantitative data: The beans were light green in color The ostrich gained 4.3 grams over a period of 6 weeks The beaker contained 300 mL of red liquid

Making a Valid Hypothesis Must make a prediction Must be stated in the “If … then…” format Must be testable

Experimental Design B A fish was taken from one fish tank with a population of sixty fish to another fish tank with a population of six fish. The fish’s rate of breathing decreased. What was the most probable cause for this decrease? The population density did not change. The temperature in the tank increased. The concentration of oxygen in the tank decreased. The concentration of carbon dioxide in the tank decreased.

Experimental Design B A fish was taken from one fish tank with a population of sixty fish to another fish tank with a population of six fish. The fish’s rate of breathing decreased. What was the most probable cause for this decrease? The population density did not change. The temperature in the tank increased. The concentration of oxygen in the tank decreased. The concentration of carbon dioxide in the tank decreased.

Tools of the Biologist Scientists use the Metric System of Measurement (S.I.) based on multiples of 10 Scientific data are recorded in tables and graphs Examples of metric units:

Experimental Design A A scientist has planned an experiment where the growth of mice populations in four aquariums is observed. Each aquarium will initially contain 10 mice and will receive the following food regimens: Aquarium 1: 5 grams food pellets/day Aquarium 2: 7 grams food pellets/day Aquarium 3: 10 grams food pellets/day Aquarium 4: 15 grams food pellets/day What is the scientists most likely studying in this experiment? a. The effect of habitat size on mice population growth b. The effect of available food resources on mice population growth c. How resource availability changes in a given environment d. The effect of mice population on hawk population

Experimental Design A A scientist has planned an experiment where the growth of mice populations in four aquariums is observed. Each aquarium will initially contain 10 mice and will receive the following food regimens: Aquarium 1: 5 grams food pellets/day Aquarium 2: 7 grams food pellets/day Aquarium 3: 10 grams food pellets/day Aquarium 4: 15 grams food pellets/day What is the scientists most likely studying in this experiment? a. The effect of habitat size on mice population growth b. The effect of available food resources on mice population growth c. How resource availability changes in a given environment d. The effect of mice population on hawk population

Microscope Basics 1. Compound Light Microscope: uses light reflected by two or more lenses We have many of these in the room Used to see Living objects Special Type of Scope: Stereoscope 2. Electron Microscope Uses electrons reflected by magnets. Can be used only with dead or non-living specimens These are very large, about the size of the teacher desk up to the size of a whole room

Scope Vocabulary Field of view Working Distance Depth-of-field What you see when looking in the eyepiece Gets smaller when you increase magnification Working Distance Distance between objectives and stage Gets smaller when you use the high power objectives Depth-of-field Occurs when you are looking closely at the layers of a specimen, you can actually see different layers at the same time!

Compound Light Microscopes versus Stereoscopes Eyepieces (2 vs 1): 2 eyepieces allow for a 3-D image Lights (2 vs 1): 2 lights allow you to see solid objects Size of Object: Larger working distances allows you to see bigger things

Marty Martian was sent to Earth by the Martian government to The Martian and the Car Marty Martian was sent to Earth by the Martian government to find life. While on Earth, Marty captured a car and brought it back to Mars. He thought he'd found a good example of life on Earth. The Martian government does not believe that the car Marty brought back is alive. Marty must stand trial for failing to perform his Martian duties. At the trail, Marty spoke in his defense. "I first saw these life forms rolling along roads in great numbers. They were giving off thick clouds of poisonous waste as they moved. They seemed to exhibit herding behavior, as many of the cars moved in the same direction. They appeared to have a great deal of energy, some of them moved faster than 60 kilometers per hour. When one of these life forms stopped or slow down, the others behind it responded. They slowed down and gave off a reddish light from the back, and sometimes they would make honking noises. I observed that they would stop to feed on a liquid substance." Take the part of Marty's defense attorney and make a good case for the car's being alive. Then be the prosecutor and show that the car is a nonliving thing. Defense Attorney Prosecutor 1. ___________________________________ 1. _________________________________ 2. ___________________________________ 2. _________________________________ 3. ___________________________________ 3. _________________________________ 4. ___________________________________ 4. _________________________________ 5. ___________________________________ 5. _________________________________