1. Section 1 World of Biology  What do biologists study?  Study of life  Gain an understanding of the natural world  Make more informed decisions on issues that impact you and our society

2. Living vs. nonliving Seven characteristic shared by living things –Organization and Cells Order of internal & external parts –Cells: smallest unit that can perform life processes –Tissues: groups of similar cells –Organs: structure that carries out specialized jobs –Organ systems: groups of specialized parts that carry out a certain function –Organism: a living thing Order of organisms interactions with the living world Unicellular Organism Biological Molecules Organelles Multicellular Organism

3.  Response to a stimulus  Physical or chemical change in the environment  Example: dilation of pupils at night  Homeostasis  All living things maintain stable internal conditions

4.  Metabolism  Living things use energy  Metabolism = sum of all chemical processes that occur in an organism  Example: Photosynthesis and digestion  Growth and Development  Growth is a result of cell division and cell enlargement  Cell division: the formation of two cells from an existing cell  Development: process in which an organism becomes a mature adult  Involves cell division  Involves cell differentiation – cell are specialized for specific function

5.  Reproduction  Not essential for survival  Needed for the continuation of species  Organisms transmit hereditary information to their offspring  DNA (deoxyribonucleic acid) hereditary information  Gene short segment of DNA that codes for a single trait (example: eye color)  Sexual Reproduction hereditary information is combined from a male and a female  Asexual Reproduction hereditary information is not combined – offspring is genetically identical to parent  Change through time  Individuals change over lifetime, but genetics don’t  Populations evolve to survive in a changing world

6. Section 2 Themes in Biology  Diversity and Unity of Life  Diversity  Variety of life on Earth  “Tree of Life” - Model that shows the unity of life  Living things unified by two features  Genetic code  Organelles in cells  Organisms that have similar sets of genes are on closer lineages  More distantly related organisms are on more distant lineages  All of life is connected through descent with modification  Three Domains of Life  Main branches of the “tree” are domains  Bacteria, Archaea, and Eukarya  Another system of grouping is the six kingdom

7.  Interdependence of Organisms  Ecology - study of interactions of organisms with each other and their environment  Ecosystems – communities of living species and their physical environments  Organisms depend on other organisms  Organisms depend on gases, water, nutrients, minerals in the physical surroundings  Humans have a huge effect on the environment

8.  Evolution  Populations change over generations  Evolution  Populations genetically change over time – descent with modification  Genetically distinct populations develop – new species  Organisms alive today are related to those in the past  Natural Selection  organisms that have certain favorable traits - better able to successfully reproduce  Adaptations – traits that improve an individual’s ability to survive and reproduce

9. Section 3 The Study of Biology Asking Questions Hypothesizing Predicting Drawing Conclusions Experimenting Data Analysis Communicate Results Observations Steps of the Scientific Method

10. Controlled Experiment Control GroupExperimental Group Constants Variable Independent VariableDependent Variable Control

11.  Collecting and Analyzing Data  Quantitative Data - in the form of numbers  Length, 5 meters  Volume, 2 liters  Mass, 3.5 kilograms  Qualitative Data - contains the characteristics of the object or event  Liquid is green  Powder smells like detergent  Surface feels rough  Drink tastes sweet  It is a ringing sound  Analyze data  Determine if reliable – sources of error  Support or dismiss hypothesis  Display data in tables or graphs

12.  Drawing Conclusions  State whether or not a hypothesis is supported  Can only disprove a hypothesis, not prove  Cannot account for unknown phenomena  Supported hypothesis is tentative – revised as new information is gathered and understood  Inferences - conclusion made on the basis of facts and previous knowledge rather than on direct observation  Models – represent or describe phenomena  Theory  Repeatedly supported related hypotheses  Highly tested, accepted principle that explains a vast number of observations and experimental data

13. Scientific Communication  Examination and verification by other scientists – peer review  Publishing a paper  Introduction  Materials & Methods  Results  Discussion  Honesty and Bias  Disprove ideas and verify previous ideas  Avoid conflict of interest

14. Section 4 Tools and Techniques Tool used to improve the performance of a task  Compound Light Microscope  Shine light through very thin specimen  Two lenses magnify an image  5 Major Parts  Eyepiece  Objective lens  Stage  Light Source  Focus Adjustment Knobs

15.  Electron Microscopes  Use electron beam to produce an enlarged image of the specimen  Scanning electron microscope  Specimen covered with metal coating  Bombarded with stream of electrons  Metal emits electrons back to a detector  Produces 3-dimensional image, 100,000X magnification  Transmission electron microscope  Transmits beam of electrons through thinly sliced specimen  Magnetic lenses enlarge image and focus on plate 200,000X magnification

16.  Measurement  International System of Measurement, SI  Base units – describe length, mass, time, and other quantities  Derived units – mathematical relationship between two or more base units  Area  Volume  Density

17.  Lab Safety  Establish SAFE common sense habits  NEVER work alone in the lab or without proper supervision by the teacher  ALWAYS ask your teacher before using equipment  LISTEN to lab instruction so you know safe practices in the laboratory

18. Using a meter stick, LENGTH Figure 1. This meter stick is calibrated in centimeters (shown as the numbered major divisions) with a least count of millimeters. Figure 2. An example of a meter stick reading. The object's length is measured to be 41.64 cm.

19. Correctly reading a graduated cylinder Correct: Viewing the meniscus at eye level Incorrect: Viewing the meniscus from an angle

20. Reading a graduated cylinder, VOLUME Step 1: Determine the scale increment Step 2: Use the graduations to find all certain digits. Step 3: Estimate the uncertain digit and take a reading

21. Measuring mass The far beam reads only in 10 g increments. The middle beam reads only in 100 g increments. The weight on the front beam can be placed to read continuously from 0 to 10 grams. The weights in each of these must always sit in a "notch". They cannot be placed at arbitrary points on the beam.

22. Temperature Determine if the thermometer is in Celsius or Fahrenheit Determine the scale increment Read the temperature DO NOT SHAKE THERMOMETER TO LOWER TEMPERATURE

23. DENSITY Density defined in a qualitative manner as the measure of the relative "heaviness" of objects with a constant volume. Density may also refer to how closely "packed" or "crowded" the material appears to be For example: A rock is obviously more dense than a crumpled piece of paper of the same size.

24. Measuring density The formal definition of density is mass per unit volume. Density = mass = g/mL volume Mass of an object ÷ Volume of same object