EXPLORING AND CLASSIFYING LIFE- Chapt 1 Science- Science is an organized way of studying things and finding answers to questions Branches of science- Life, Earth and Physical science

Branches of Science Life Science- the study of living things Earth Science- the study of Earth,itys landforms, rocks, soil, and forces that shape the Earth’s surface. Physical Science- The study of chemistry and physics.

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

SCIENTIFIC THEORY- an explanation of observations or events based on knowledge gained from many observations and investigations. SCIENTIFIC LAW- describes a pattern or an event in nature that is always true.

Measurement Precision- describes how similar or close measurements are to each other. Accuracy- how close a measurement is to an accepted value. Significant digits- communicate the precision of the tools used to make measurements. Tools scientists use: journals, microscopes, balance, computers, magnifying lenses, dissecting tools, etc.

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. Constant- factors in an experiment that stay the same.

The international System of Units(SI) Common SI measurements Length- millimeter, centimeter, meter, kilometer Volume- Milliliter, liter Mass- gram, kilogram, tonne

Scientific tools Microscopes Computers Triple beam balance Thermometers Glassware Dissecting tools

CLASSIFYING AND EXPLORING LIFE UNIT 1 CLASSIFYING AND EXPLORING LIFE

Living Things 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

Cells can be: Multicellular- living things made of two or more cells Unicellular- Living things with only ONE cell

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. This is an example of REGULATION. All of the interactions that take place during an organisms life are called development.

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

CLASSIFICATION

Binomial Nomenclature- The system used by modern scientists to name organisms Genus- a group of similar species Species- a group of organisms that have similar traits and are able to produce fertile offspring. Field guides and dichotomous keys are used to identify organisms

Dichotomous Key