Put the following parts of the scientific process in order from 1 st to last… 1. ___a. publish results 2. ___b. hypothesis 3. ___c. write and do experiment 4. ___d. conclusion 5. ___e. ask a question 6. ___f. analyze data 7. ___g. observation

KEY CONCEPT Biology is the study of all forms of life.

Earth is home to an incredible diversity of life. The biosphere includes all living things and all the places they are found. biosphere = everywhere life exists

Earth is home to an incredible diversity of life. Every part of the biosphere is connected with every other part. The biosphere includes many environments. –land environments

–saltwater and freshwater environments –portions of the atmosphere Tidepool Estuary

–Biodiversity generally increases from the poles to the equator. –Biodiversity is greater in areas with consistently warm temperatures. Biodiversity is the variety of life. Biodiversity is greater closer to the equator.

–Members of a species can interbreed to reproduce. –There are about 2 million different living species have been identified. A species is one particular type of living thing.

Defining Life Properties that we share with all other living things…

How would YOU define life?

Biology is the science of life!  Scientists want to apply a single definition to all life – and do so through – you guessed it…. Lot’s of OBSERVATION!

Two important vocab words…  BIOTIC = living/alive  ABIOTIC = non-living

Can you tell what’s living?

You get the idea… All living things share certain properties… In order to be considered living, ALL FIVE properties must be present. What are they???

Property #1: CELLULAR ORGANIZATION  ALL living things are composed of one or more cells (can have 1 to trillions of cells).  All cells grow and reproduce

Property #2: METABOLISM  Living things need energy! To grow To grow To move To move To process information To process information  Metabolism= sum of chemical reactions carried out by an organism

Property #3: HOMEOSTASIS  Living things maintain stable internal conditions.  They RESPOND TO THE ENVIRONMENT What is the temperature that the human body maintains? What is the temperature that the human body maintains?

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings HOMEOSTASIS Normal room temperature Figure of 6

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings RECEPTOR Thermometer STIMULUS: Room temperature rises Normal condition disturbed HOMEOSTASIS Normal room temperature Figure of 6

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings RECEPTOR Thermometer STIMULUS: Room temperature rises Normal condition disturbed HOMEOSTASIS Normal room temperature Information affects CONTROL CENTER (Thermostat) 20 o 30 o 40 o Figure of 6

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings RECEPTOR Thermometer STIMULUS: Room temperature rises Normal condition disturbed HOMEOSTASIS Normal room temperature EFFECTOR Air conditioner turns on Sends commands to Information affects CONTROL CENTER (Thermostat) 20 o 30 o 40 o Figure of 6

RECEPTOR Thermometer STIMULUS: Room temperature rises Normal condition disturbed HOMEOSTASIS Normal room temperature RESPONSE: Room temperature drops Normal condition restored EFFECTOR Air conditioner turns on Sends commands to Information affects CONTROL CENTER (Thermostat) 20 o 30 o 40 o Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure of 6

Property #4: REPRODUCTION  No living thing is immortal (lives forever) so…  It must be able to reproduce from one generation to the next – or there would be no life left!

Property #5: HEREDITY  DNA is inside cells coding to direct growth and development of all living things Parents pass on characteristics to their offspring through their genes.Parents pass on characteristics to their offspring through their genes.

Which property of life is most important??  A. cellular organization  B. homeostasis  C. heredity  D. reproduction  E. metabolism  Be prepared to argue WHY!!!

Why can’t we just choose one characteristic to define life?  Do any non-living things possess any of the characteristics of life?

Once life has been found or described, scientists strive to organize their knowledge!

 The study of life extends from molecules and cells to the entire living planet  Biological organization is based on a hierarchy of structural levels Biologists explore life from the microscopic to the global scale

A Hierarchy of Biological Organization General to Specific… 1. Biosphere: all environments on Earth 2. Ecosystem: all living and nonliving things in a particular area 3. Community: all LIVING THINGS in an ecosystem

4. Population: all individuals of a specific species in a particular area 5. Organism: an individual living thing

6. Organ systems: groups of organs functioning together 7. Organs: specialized body parts made up of tissues 8. Tissue: a group of similar cells

And the smallest units… 9. Cell: life’s fundamental unit of structure and function 10. Organelle: a structural component of a cell 11. Molecule: a chemical structure consisting of atoms

Ecosystems The biosphere Organisms Populations Communities Cells Organelles Molecules Tissues Organs and organ systems Cell 1 µm Atoms 10 µm 50 µm