7 th Science Chapter 1

 Section 1: The Work of Science  Types of Science  1. Earth science – atmosphere, solar system, geology (rock layers, volcanoes, etc.)  2. Life science – plants, animals, other living things  3. Physical science – matter and energy – chemistry and physics

 Critical Thinking  Thinking in depth, trying to find an answer, separating important information from unimportant information

 Solving Problems  Scientific Method  -State the Problem  -Gather Information  5 senses – taste, touch, smell, sight, hearing  Make observations  -Form a hypothesis  A prediction about what you think will happen

 -Test hypothesis with an experiment  You can only change one variable at a time!  -Analyze data  Set up charts, graphs, tables  -Draw Conclusions  Logical answer based on observations, data, and analysis  Report Results  Communication with other scientists

 Measuring with Scientific Units  Scientists use the SI system (metric), based on units of 10.  Length – meter (m)  Volume – liter (L), centimeter cubed (cm3)  Mass – gram (g)

 Safety  Most important safety rule is ask your teacher before beginning anything.

Section 2  Section 2 – Living Things  An organism is any living thing, no matter how big or small  Examples of nonliving things: water, air, sun, clouds  Living things are organized  Cell – smallest unit  Tissues  Organ  Organ system (digestive, circulatory)  Organism

 Some organisms are made up of only one cell, some have many cells.  Living things react to their surroundings.  Anything that causes some change in an organism is called a stimulus.  The reaction to a stimulus is called a response.  Stimuli is more than one stimulus

 Homeostasis – ability to keep a balance within the body no matter what conditions are outside the body.  Living things use energy  Plant – use the Sun’s energy to make their own food (photosynthesis)  Humans – eating food

 Living things grow and develop  Increase in the number and size of their cells.  Living things reproduce  Without reproduction the species would become extinct.  Living things need a proper place to live.  Raw materials – food, drink, oxygen

Classifying  Spontaneous Generation – old belief  Biogenesis – New (current Belief)  Spontaneous Generation – Life could arise from non- living materials.  Biogenesis – Life can arise ONLY from Life  Pasteur finally showed that living things do not come from nonliving things

Classification  Aristotle – was one of the first people to classify organisms  Plant or Animal  Linnaeus – simplified the system  Still use Linnaeus’s system today  Binomial Nomenclature – two-word name used to classify living things  It minimizes confusion among scientists  System provides information about the species  Classifies organisms by traits and evolutionary histories

 Classification  Based in LATIN  Two Words ( Genus + Species or specific name)  Capitalize ONLY the FIRST word – Genus)  Second word is the Species (Not Capitalized )  Written in Italics or Underlined  Scientific name for humans = Homo sapien  Scientific name for wolf – Canus lupus

 An advantage of our scientific naming system is that biologists can communicate regardless of their native languages. Minimizes confusion

 Scientific names prevent confusion.  Two different organisms can NOT have the same scientific name but they might have the same common name.  The easiest and most efficient field guide to use to identify an organism would be a dichotomous key.  The dichotomous key uses TWO paired descriptions at each step.

 The dichotomous key has three basic functions  Avoids errors in communication  It classifies organisms with similar evolutionary histories together.  It gives descriptive information

Classification divisions  Kingdom  Phylum ( Division- Plants)  Class  Order  Family  Genus  Species - most inclusive / most similar

 Each level of classification is based on SHARED characteristics  Family is made up of similar Order  Class is made up of similar Phylum  Species is made up of similar Genus  Etc..  Broadest group – Kingdom  Most Inclusive – Species  Species - Organisms that are similar in structure and form and successfully reproduce among themselves.

The Six Kingdoms  The classification system most commonly used today separates organisms into six (6) Kingdoms  Each level of classification contains all organisms that share the same characteristics

6 - Kingdoms ArchaebacteriaEubacteriaProtistaFungiPlantaeAnimalia

Characteristics -Kingdoms  Cell Type - Prokaryote or Eukaryote  Body Form - Unicellular/ Multicellular /Both  Food Getting - Heterotrophs / Autotrophs  Complex organ systems - Yes / No

Cell Type Prokaryote – No internal membrane bound organelles - No Nucleus Eukaryote – Has internal membrane bound organelles Archaebacteria - Proraryote Eubacteria - Prokaryote Protista – Eukaryote Fungi - Eukaryote Plantae - Eukaryote Animalia - Eukaryote

Body Form Archaebacteria - Unicellular Eubacteria - Unicellular Protista – Both (Unicellular & Multicellular) Fungi - Both (Unicellular & Multicellular) Plantae - Multicellular Animalia - Multicellar

Food Getting Method Archaebacteria – autotrophic (chemosynthesis) Eubacteria – both (autotrophic & Heterotrophic) Protista - both Fungi - Heterotrophic Planate – Autotrophic (Photosynthesis) Animalia – Heterotrophic Autotroph – makes own food Heterotroph – Consumes others

Presence of Systems Archaebacteria - No Eubacteria - No Protista - No Fungi - No Plantae - Yes Animalia - Yes