CHAPTER 1 NOTES THE SCIENCE OF LIFE

40 MILLION SPECIES ORGANISM- LIVING THING BIOLOGY- THE STUDY OF LIVING THINGS

SECTION 1 THE WORLD OF BIOLOGY CHAPTER 1 SECTION 1 THE WORLD OF BIOLOGY

Characteristics of Life Organization and Cells Response to Stimuli Homeostasis Metabolism Growth and Development Reproduction Change Through Time

Organization and Cells CELLS- Basic unit of structure and function ORGANIZATION- at both molecular and cellular levels- particular cells carry out specific functions atoms  molecules  organelles  cells  organs  organ systems  organism

CELL STRUCTURE AND FUNCTION Cell- basic unit of structure and function Unicellular organisms- one celled Multicellular organisms- more than one cell Cells are highly organized. Cell Differentiation- the development of cells having special functions

STABILITY AND HOMEOSTASIS Homeostasis- stable level of internal conditions

Metabolism ENERGY USE METABOLISM – sum of all chemical processes that occur in an organism Energy maintains organization

Growth and Development GROWTH- result of cell division and enlargement Development- process by which adult organism arises (puberty)

REPRODUCTION AND INHERITANCE REPRODUCTION- the production of new offspring transmits heredity info to offspring (DNA) gene- a short segment of DNA that contains the instructions for the development of a single trait Sexual reproduction- the production of offspring from the combination of genetic material from two parent organisms Asexual reproduction- the production of offspring that does not involve the union of gametes (sex cells)

EVOLUTION Populations of organisms evolve or change over time. Allows for survival in a changing world Assists with the diversity of organisms

Section 2 Themes in Biology

BIOLOGY THEMES 3 Themes in Biology Diversity and Unity of Life Interdependence of Organisms Evolution of Life

Unity in the Diversity of Life There are certain features that all living things have in common: Genetic code = the rules that govern how cells use the hereditary information in DNA Presence of organelles

Three Domains of Life 6 Kingdoms Bacteria Archae Eukarya 4 in Eukarya (Protista, Fungi, Animalia, and Plantae) 1 in Arachae (Archae) 1 in Bacteria (Bacteria)

INTERDEPENDENCE OF ORGANISMS Ecology - the study of the interaction of organisms with one another and their environment Ecosystems- environmental communities

Evolution of Life Evolution = descent with modification- a process in which the inherited characteristics within populations change over generations such that genetically distinct populations and new species can develop Natural selection = the process by which individuals that are better adapted to their environment survive and reproduce more successfully than less well adapted individuals

MATTER, ENERGY AND ORGANIZATION Living things are composed of highly organized matter Organization requires energy Photosynthesis- energy from sun is changed into a form of energy that can be used by living things autotrophic- make their own food (producers) Heterotrophs- organisms that must take in food to meet their energy needs (consumers)

CHAPTER 1 SEC. 3 THE STUDY OF BIOLOGY

Steps of the Scientific Method Make an observation with the senses Ask a question about the observation Collect data Hypothesize Prediction Experiment Draw Conclusions Communicate

COLLECTING DATA DATA- all info gathered in trying to answer a question- includes: Observation Qualitative- what we see or gather with senses Measuring Quantitative- what we measure using instruments and numbers Sampling- using a small part to represent the entire population; which must be large and random Organizing data- charts, graphs, tables, maps etc

HYPOTHESIS DEFINITION- A STATEMENT THAT EXPLAINS A SCIENTIST’S OBSERVATIONS AND DATA AND CAN BE TESTED Can be proved wrong, but can never be proved beyond all doubt Are often refined, revised or discarded based on new evidence

PREDICTION A STATEMENT MADE IN ADVANCE THAT STATES THE RESULTS THAT WILL BE OBTAINED FROM TESTING A HYPOTHESIS “IF…..THEN……..

EXPERIMENT DEFINITION: testing a hypothesis or prediction by gathering data under controlled conditions CONTROLLED EXPERIMENT involves the following: Control group- a group or individual that serves as a standard of comparison with another group or individual to which it is identical except for one factor- “the norm”

(Experiment cont.) EXPERIMENTAL GROUP- group or individual that is exposed to the factor/variable INDEPENDENT VARIABLE- an experimentally manipulated variable- the one thing you are testing- that you change DEPENDENT VARIABLE- the responding variable in an experiment (results for action of the independent variable)

ANALYZING DATA FROM EXPERIMENT IS DATA RELIABLE? OFFER SUPPORT? REJECT? MAKE STATISTICS; COMPARE WITH OTHER STUDIES LOOK FOR SOURCES OF ERRORS

DRAWING CONCLUSIONS Model- an explanation supported by data Inference- a conclusion made on the basis of facts or premises rather than on direct observations Theory- a broad and comprehensive statement of what is believed to be true, supported by considerable experimental evidence from related hypothesis

COMMUNICATION Report findings in journals, at meetings, etc. Allows scientists to repeat and/or expand on previous work

CHAPTER 1 SEC 4 TOOLS AND TECHNIQUES

MICROSCOPES MAGNIFICATION- the increase of an object’s size to allow viewing RESOLUTION- the power to show details clearly FOUR BASIC TYPES OF MICROSCOPES: Compound light microscope (LM) Stereomicroscope Transmission electron microscope (TEM) Scanning electron microscope (SEM)

LIGHT MICROSCOPE Light transfers through a thin specimen on a slide Parts of light microscope Stage- supports slide and specimen Objective lens- enlarges t he image Ocular lens- magnifies image even more Nosepiece- holds and rotates the objectives Diaphragm - changes the amount of light to reach the specimen

Course focus/adjustment- the focus to be used at lower powers- DO NOT USE AT HIGH POWER Fine focus/adjustment- the focus to be used at high power for more precise images Power of magnification- the total amount of magnification- ocular lens is 10 X Multiply 10X by the objective lens Ex. 10x X 40x = 400 power

Eye piece Ocular lens Body tube Nosepiece Objective lens Stage Diaphragm Light source Course adjustment Fine adjustment Base

STEREOMICROSCOPE Used to view larger objects Usually only has 2 objectives- ours has a 5 and 10 power

TRANSMISSION ELECTRON MICROSCOPE Transmits a beam of electrons through a thin slice Focuses on a screen or photographic plate Can magnify up to 200,000 times BUT cannot be used to view live specimens

SCANNING ELECTRON MICROSCOPE Three-dimensional images- no living Specimens are not sliced- but are sprayed with a metal coating which emits a shower of electrons when the beam of electrons is passed over it Electrons are passed onto a photographic plate Magnify up to 100,000 times

MEASUREMENT SI= Systeme International d’Unites BASE UNITS- Length = meter = m Mass = kilogram = kg Time = second = s Electric current = ampere = A Temperature = Kelvin = K Amount of substance = mole = mol Volume = liter = l

Metric Prefixes Based on the power of ten Kilo 1000 Hecto 100 Deka 10 Meter, liter,gram Deci .1 Centi .01 Milli .001 Micro .000001 Nano .000000001

Units DERIVED UNITS- when two base units combine Volume= m3

LAB SAFETY http://www.youtube.com/watch?v=z_J9wMSbkZI http://www.youtube.com/watch?v=KR-PyIrcwaU http://www.youtube.com/watch?v=ug8j_0mNRfs