Chapter 1The Science of Life

•I. Themes of Biology

•A. Cell Structure and Function

•1. Unicellular

•2. Multicellular

•3. Cell differentiation

•B. Stability and Homeostasis

•The ability to maintain a stable level of internal conditions.

•C. Reproduction and Inheritance - transfer of genetic material from parents to offspring.

•1. Asexual reproduction

•2. Sexual reproduction

•D. Evolution

•A theory that species change over time due to natural selection.

•E. Interdependence of Organisms

•1. Ecology - interaction of organisms and their environment.

•F. Matter, Energy, and Organization

•1. Autotroph - produces nutrients by photosynthesis.

PlantsAlgae

Cyanobacteria

•2. Heterotrophs - obtain nutrients.

Animals

Fungi

•II. The World of Biology

•A. Characteristics of Life

•1. Composed of Cells - microscopic units of life.

•2. Organized at the molecular and cellular levels.......functions.

•3. Use energy in a process called metabolism......allows for growth.

•4. Homeostasis - internal balance.

•5. Growth - occurs through cell division.

•6. Reproduction - continuity of the species.

6 Kingdom Classification System

•III. Scientific Methods

•A. Processes used to develop questions or discover facts.

•1. Observing

•2. Collecting data

•3. Measuring data

•4. Organizing data

•5. Classifying

•6. Hypothesizing

•7. Predicting

•8. Experimenting

•9. Analyzing data

•10. Modeling

•11. Inferring

•12. Communicating

•B. Scientific Method - a logical, orderly way to solve a problem or answer a question.

•1. Define the problem.

•2. Research.

•3. Form hypothesis - trial solution.

•4. Experiment to test hypothesis.

•Experimental group - variable tested.

•Control group - “comparison”.

Steps:

•5. Observe and record data.

•6. Draw conclusions.

•Theory - hypothesis supported by many experiments.

•Law - theory supported by many experiments.

•IV. Microscopy and Measurement

•A. Microscopes

•1. Light microscope - light produces the image.

•Magnification - enlarge.

•Resolution - clarity.

Video - “Introduction to the Microscope”

Light Microsco

pe

•Total Magnification = eyepiece x objective

•2. Electron Microscope - uses a beam of electrons focused by magnets to produce an image.

•TEM - very powerful.

•SEM - 3-D image.

TEM

TEM Micrograph:nucleus of a cell

SEM

SEM Micrograph:Head of a fly