Science
use of evidence to construct testable explanations and predictions of natural phenomena
Why Science is different
deals only with natural world scientists collect & organize information, looking for patterns & connections among events scientists propose testable explanations based on evidence & understanding
Goals of Science
provide natural & testable explanations for events in the natural world use these explanations to understand patterns in nature & to make useful predictions about natural events
Scientific Methodology
observing & asking questions forming hypotheses conducting controlled experiments collecting & analyzing data drawing conclusions
Observation
act of noticing & describing events or processes in a careful, orderly way
Inference
logical interpretation based on what scientists already know
Hypothesis
tentative scientific explanation that can be tested by further observation or by experimentation
Controlled Experiment
experiment in which only one variable is changed if several variables are changed, researchers can't tell which variable is responsible for observed results
Independent variable
variable that is deliberately changed (i.e. amount of fertilizer, type of bridge)
Dependent variable
variable that is observed & that changes in response to independent variable (i.e. plant height, weight held by bridge)
Control Group
exposed to same conditions as experimental group except for changes in the independent variable
2 types of data
quantitative - numbers obtained by counting or measuring qualitative - descriptive & involve characteristics that cannot usually be measured
Sample Size
larger sample sizes enable researchers to more reliably analyze variation within each group & evaluate differences between experimental and control groups
Theory
tested, highly-reliable scientific explanation of events in the natural world unifies many repeated observations incorporates durable, well-supported hypotheses that enable scientists to make accurate predictions may be revised or replaced as new evidence is uncovered
Scientific Attitudes
curiosity open-mindedness skepticism creativity
Scientific Journals
scientists share findings by publishing their hypotheses, experimental methods, results, and analysis in scientific journals scientific papers are reviewed by anonymous, independent reviewers who work in the same field publishing articles in peer-reviewed scientific journals allows researchers to share ideas and to evaluate & test the data and analysis
Bias
personal, rather than scientific, point of view for, or against, something
Biology
scientific study of life
Characteristics of Living Things
made up of basic units called cells reproduce based on a universal genetic code grow & develop obtain & use materials and energy respond to their environment maintain a stable internal environment evolve (change over time)
Cells
smallest units of an organism that can be considered alive
2 kinds of reproduction
sexual: cells from two different parents unite to form first cell of new organism asexual: single parent produces offspring genetically identical to parent
DNA
genetic material that organisms inherit from their parents
Metabolism
combination of chemical reactions through which an organism builds up or breaks down materials
Stimulus
signal to which an organism responds
Homeostasis
relatively constant internal physical & chemical conditions that organisms maintain
Viruses
particles made up of proteins, nucleic acids (i.e. DNA), and sometimes lipids parasites that depend entirely upon other living organisms can reproduce, regulate gene expression,& evolve after infecting living things
Cell Differentiation
process by which cells begin to look different from one another and perform different functions
Central Concepts of Biology
cause & effects stems & system models ability & change patterns scale, proportion, & quantity energy & matter flows, cycles, & conservation structure & function
Metric System
used by scientists when collecting data & performing experiments decimal system of measurement whose units are based on certain physical standards scaled on multiples of 10