Intro to ‘Biology’  Biology – the science of life  Organism – a “living thing” Therefore, biology studies organisms ∙ microscopic structure ∙ interaction among many ∙ life history

THEMES of BIOLOGY Evolution – change over time Reproduction & Inheritance – DNA/Genetics Structure & Function – examples??? Energy – required for life Ecology – interactions Science & Society – conservation, bioethics, etc.

What is Life??? The Characteristics of Life: made of cells Think about some of the things you see in your everyday life… Animals Trees Rocks Water Soil Buildings Cars You probably have an idea about which of these is alive and which are not. Scientists use the following characteristics to determine if something is alive or not. In order to qualify, the thing in question much possess all of the characteristics. The Characteristics of Life: made of cells has organization uses energy responds to the environment grows reproduces * Try applying these to the list above*

Hydrology 11. Endocytosis Cytology 12. Insecticide Use the word fragments in your list to figure out the meaning of the following terms: Hydrology 11. Endocytosis Cytology 12. Insecticide Protozoa 13. Anaerobic Epidermis 14. Bilateral Spermatogenesis 15. Endotherm Cytoskeleton 16. Subspecies Abiotic 17. Arthropod Dermatitis 18. Micrometer Hypodermic 19. Hypothermia Hemophilia 20. Photosynthesis

STRUCTURES AND FUNCTIONS Write the correct term—autotroph or heterotroph—in the space referring to each of the organisms pictured below.

The Scientific Method What is it used for??? Answering questions about the world around us It does so in an organized and systematic way THE STEPS OF THE SCIENTIFIC METHOD Identify the problem/question Observe Form a testable hypothesis Experiment (collect data) Analyze data Draw a conclusion Repeat!

Experimental Design Pre-planned series of steps Goal is to collect (good) data Most important part of the Scientific Method “Controlled Experiment” Gathers data under controlled conditions Comparison of two (almost identical) groups Control Group: Receives the normal (control) treatment Experimental Group: Receives the experimental treatment Independent Variable: Only difference between groups “What did I change?” Dependent Variable: Data gathered during experiment “What did I measure?”

Drawing a Conclusion EITHER: Analyze your data by creating charts/tables/graphs Look for patterns/trends Your results should point towards a conclusion... EITHER: “the data collected supports… (the hypothesis)” OR “the data collected does not support… (the hypothesis)” THEORY: A statement widely considered to be true because it has been supported by extensive experimental evidence

Quantitative Data Examples: - tree branch length - cell count Numerical information gathered through experimentation Examples: - tree branch length - cell count - colony diameter It is important for scientists to use a standard system of measurement SI = international system of measurement (a.k.a. the metric system) BASE UNITS: Length → meter Mass → gram Volume → liter

Metric Number Line

Metric Conversions 0.023 0.000214 5160. 1.4 0.2 34. 0.01 27.6 0.314 41.17 8,700. 290,000. 36. 0.00007 9.1 10.6 76.5 104.9 0.019 0.396 140. 0.000025

Metric Conversions 0.001 7,100. 0.0004 146,100. 0.0182 22,100. 0.0217 0.0001087

Microscopy A microscope produces an enlarged image of an object * MAGNIFICATION * COMPOUND LIGHT MICROSCOPE Used to view small organisms and cells Thinly sliced specimen mounted on a glass slide 2 LENSES: - Ocular (eyepiece) - Objective (adjustable) Total Magnification = ocular × objective

Compound Light Microscope Diagram

Compound Light Microscope Diagram

How to … MICROSCOPES! - If unsure, follow directions in your handout! Read, read, read!!! - Handle the microscope with one hand on the arm and the other giving support underneath the base Always begin viewing under LOW power Start with the lens as close to the stage as possible, then pull away with the coarse knob until focused Once focused under low, switch to high power - Under HIGH power, only fine focus is needed Answer all questions Make 2 sketches for each slide viewed

Other forms of Microscopy Light microscopes magnify with a beam of light Electron microscopes do so with a beam of electrons TEM – transmission electron microscope SEM – scanning electron microscope Pro: Magnify many thousands of times (instead of hundreds) Con: Cannot view living specimens

Transmission Electron Microscope

TEM image of bacteria cells (magnified 50,000x)

SEM with opened sample chamber

SEM image of various types of pollen