EXPLORING AND CLASSIFYING LIFE- Chapt 1 Science- Science is an organized way of studying things and finding answers to questions

The scientific method 1. State the problem 2. gather research 3. form hypothesis 4. experiment 5. analyze data 6. draw conclusions- valid or invalid

Control- the standard to which the outcome of a test is compared. Variable- something in a experiment that can be changed. * The number of variables that should be changed during an experiment is one. Scientist use the SI system (International system of Units) for measurements.

Common SI measurements Length- millimeter, centimeter, meter, kilometer Volume- Milliliter, liter Mass- gram, kilogram, tonne

Safety in the lab -proper eye protection Wash your hands

Living Things Organism – any living thing Cell- smallest unit of an organism that carries out the functions of life Living things : Are organized Respond Use energy Grow and develop Reproduce * Anything that causes some change in an organism is called stimulus

Living things need: A place to live Raw materials such as water and food Homeostasis- regulation of an organisms internal, life-maintaining conditions For example- the amount of water that goes out must be the same as the amount of water that comes in. All of the interactions that take place during an organisms life are called development.

What do living things need? A place to live raw materials – water and food Homeostasis- balancing the amount of water taken in with the amount of water lost

Where does life come from? Spontaneous generation- the idea that living things come from non-living things When scientists tested this theory, the theory changed. Biogenesis- the theory that living things come only from other living things

Life’s origins Oparins hypothesis- Alexander I Life’s origins Oparins hypothesis- Alexander I. Oparin suggested that the Earh’s atmosphere had no oxygen but was made of Amonia, hydrogen, methane and water vapor. He stated these gases combined to form complex compounds found in living things The Miller- Urey experiment did not prove that Oparin’s theory was correct

How are living things classified? Carolus Linneaus- swedish naturalist, developed a system of classification Kingdom- Animalia Phylum- Chordata Class-Mammalia Order- Cetacea Family- Delphinidae Genus-Tursiops Species- Tursiops truncatus

Binomial Nomenclature- The system used by modern scientists to name organisms Genus- a group of similar species Field guides and dichotomous keys are used to identify organisms