Biology

The study of life

Characteristics of living things:

• Made up of one or more cells

• reproduce

• grow and develop

• obtain and use energy

• respond to their environment

Biology: the study of life

• Bio = life

• logy = study of

• biologist: anyone who uses the scientific method to study living things

• there are many branches of biology that vary in size and complexity

STEPS OF THE SCIENTIFIC METHOD

• Determine the problem

• observe and collect information

• make a hypothesis

• test your hypothesis by designing an experiment and performing the experiment

• analyze your results

• draw conclusions

• go back to above steps and rethink, re-experiment, and re-conclude

Tools of a biologist -microscopes

• Compound light microscopes

– most common

– 1-1000x magnification

– very versatile

– limited resolution (focusing ablility)

• Electron microscopes

– view small objects

– limit of resolution is 1000x smaller than a light microscope

• transmission

• scanning

MICROSCOPES

• TRANSMISSION

– beam of electrons shine onto sample and then magnifies the image onto a fluorescent screen

• can take pictures also

• SCANNING

– beam of electrons move back and forth across the object and forms a 3-D image on a TV screen

• only shows outside of specimen but is very detailed