Unit 1

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