Chapter 1 The Study of Life

Biology is the study of things that are alive and things that used to be alive “Bio” is Latin for life “ology” is Latin for “the study of” Biology

The act of doing science IS NOT limited to scientists Biology isn’t limited to only field biologists Beekeepers have to know how bees behave, how they work together, best placement of hives Doctors study biology before medical school Farmers, physical therapists and probably you all use some form of biology Who uses biology?

Tools of biology Microscopes Scientific measurement The Scientific Method Tools of biology

The light microscope

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In a light microscope, light passes through a specimen then through two lenses The lenses magnify the image of the specimen and it appears larger The light microscope

The two main lenses are the objective and the eyepiece (or ocular lens) The objective lens can be changed and each objective lens has a different magnification The eyepiece has an additional magnification (usually 10X) The total magnification = magnification of objective lens x magnification of eyepiece The highest powered light microscopes can magnify up to 2000 times magnification

What is the total magnification if you are using the 40x objective lens and the eyepiece has a magnification of 10x? practice

Stereo microscope The stereo microscope has two eyepieces It is used to view larger samples and specimen It is sometimes called a dissecting scope Stereo microscopes can magnify up to 60 times Stereo microscope

Electron microscopes use a beam of electrons instead of light The images can be very detailed and objects can be magnified up to 500,000 times These images cannot be in color The process is expensive and the specimen is killed during the process Electron microscopes

Scientific measurement SI units (standard internationale) These are metric units of measurement they are the standard units used by scientists all over the world Using standard units helps with consistency, and communication Scientific measurement

Scientific measurement This system is based on units of 10 Very similar to money How many pennies equal one dime? How many dimes equal one dollar? In a similar way, 10 millimeters equal one centimeter 10 centimeters equal one decimeter And 10 decimeters equal one meter Scientific measurement

Scientific method What is the scientific method? It is a series of steps used to solve problems Have you ever used the scientific method? Have you ever used it while NOT in science class? Yes, you have Scientific method

Question/problem: the problem you’re trying to solve Hypothesis: your guess as to the solution to the problem or answer to question Experiment: the procedure used to test the hypothesis Variables: things that can be changed in experiment (ex. Time, temperature, volume of a substance) Control: a standard used for comparison Data: recorded facts, observations and measurements from the experiemnt Parts of an experiment

When the experiment is complete one must analyze the data that was collected Conclusion: Comparing the data/results of experiment to the problem and hypothesis. This is done to determine whether or not the hypothesis was correct or not Drawing conclusions

A theory is a hypothesis that has been tested numerous times with similar results each time. Theories are not guesses. They are the best explanations science has to offer about a problem. theory

technology What is technology? The use of scientific discoveries to solve everyday problems is called technology Sometimes called applied science technology