CHAPTER 1 THE SCIENCE OF LIFE

BiologyMrs. Shanna Coan

The study of life

Biology

High degree of order within an organism’s internal and external

parts

Organization

Smallest unit that can perform all life’s processes

Cell

Organisms, such as bacteria, that are made up of one cell

Unicellular

Organisms, such as humans, that are made up of many cells

Multicellular

Carry out special jobs within a system

Organ

Groups of cells that have similar abilities

Tissue

Tiny structures that carry out functions necessary for a cell to stay

alive

Organelle

Chemical compounds that provide physical structure and that bring about movement, energy use, and

other cellular functions

Biological Molecule

Stable level of internal conditions

Homeostasis

Sum of the chemical reactions that take in and transform energy

Metabolism

Formation of two new cells from an existing cell

Cell Division

Process by which an organism becomes a mature adult

Development

Process where organisms produce new organisms like themselves

Reproduction

Short segment of DNA that contains the instructions for a single trait

Gene

Modern taxonomic system, broadest category, contains kingdoms

Domain

Highest category of the traditional taxonomic system

Kingdom

Branch of biology that studies organisms interacting with their

environment

Ecology

Communities of living species and their physical environment

Ecosystem

Descent with modification

Evolution

Organisms with favorable traits are better able to survive and reproduce

Natural Selection

Traits that improve an individual’s ability to survive and reproduce

Adaptation

Organized approach to solving problems

Scientific Method

The act of perceiving a natural occurrence

Observation

Educated guess

Hypothesis

A statement that forecasts what would happen

Prediction

Used to test a hypothesis

Experiment

Provides a standard against which a biologist can compare results

Control Group

In an experiment, a group that is identical to the control group except

for one variable

Experimental Group

The factor that is deliberately manipulated in an experiment

Independent Variable

The factor that changes as a result of manipulation of one or more other

factors

Dependent Variable

Explanation for some phenomena based on observation

Theory

Scientists who are experts in the field anonymously read and critique

research

Peer Review

Microscope that shines light through a specimen

Compound Light Microscope

Magnifies an image usually 10 times

Eyepiece (ocular lens)

Located directly above the slide and magnifies the image (4, 10, 100)

Objective Lens

Platform that supports a slide

Stage

Light bulb that provides light for viewing the image

Light Source

Increase in an objects apparent size

Magnification

The structure that holds the set of objective lens

Nosepiece

Power to show details clearly

Resolution

Produces an enlarged, three-dimensional image of an object using

a beam of electrons

Scanning Electron Microscope (SEM)

Transmits a beam of electrons through a very thin slice of specimen

and can magnify 200,000 times

Transmission Electron Microscope (TEM)

Standard system of measurement

Metric System

Fundamental unit of measure that describes length, mass, volume, and

other quantities

Base Unit