Chapter 1 The 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. Plants Algae 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 Microscop e

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