1. Welcome to Biology Chapter 1-Introduction to Science and Life

2. Scientific Method Begin with observations Ask questions Data Collection Quantitative observations involve numbers – counting or measuring objects. Qualitative observations involve characteristics that can’t be counted – ex. = color, texture, etc. *observation measurement sampling to be useful must be large and random organizing data graphs, charts, tables or maps

3. Scientific Method Cont. Hypothesis prediction – a statement made in advance that states the expected results from testing a hypothesis Usually an “if-then” statement Experiment conduct a controlled experiment

4. Conducting a Controlled Experiment Compares a control group with an experimental group one variable tested at a time independent variable – the experimentally manipulated variable dependent variable - the responding variable (the one you don’t control).

5. Graphing Data The independent variable is plotted on the x-axis. The dependent variable is plotted on the y- axis.

6. Drawing Conclusions Only after a careful analysis of the data. Modeling – an explanation supported by data

7. Laws, Theories, and Inferences A scientific law explains how an event occurs while a scientific theory explains why an event occurs. It is a well-tested explanation that unifies a broad range of observations. An inference is a logical interpretation based on prior knowledge & experience.

8. Observation VS. Inferences Observations The dog’s tail is wagging The man is riding a bicycle The Braves are leading the wild card Inferences The dog’s tail is wagging because he is excited. The man is riding a bicycle because his car won’t start. The Braves are leading the wild card because they are playing well right now.

9. Observation VS. Inferences

10. Microscopy and Measurement microscope - an instrument that produces an enlarged image of an object magnification - the increase of an object’s apparent size resolution - the power to show details clearly most commonly used is the compound light microscope

11. To compute the power of magnification of a microscope, the power of magnification of the strongest objective lens is multiplied by the power of magnification of the ocular lens.

12. Electron Microscopes A beam of electrons produces an enlarged image of the specimen Transmission electron microscope (TEM) 200,000X magnification cannot be used to view living specimens Scanning electron microscope (SEM) 100,000X magnification spectacular 3D detail cannot be used to view living specimens

13. Measurement Scientists use a single, standard system of measurement Systemè International d’Unités (International System of Measurements) known and loved by all as SI

14. 7 Fundamental Base Units in SI

15. Some SI Prefixes

16. Derived Units Produced by the mathematical relationship between two base units or between two derived units

17. Other Units Some units of measurement that are not part of SI are accepted for use with SI units

18. How do you define Biology? Biology- the study of life Organism- complete, individual living thing Biologist: Study the diversity of life Research diseases Develop technologies Improve agriculture Preserve the environment

19. Six Unifying themes of Biology: 1. Cell Structure and Function Unicellular: composed of one cell- Bacteria Multicellular: composed of more than one cell- Humans 2. Stability and Homeostasis Homeostasis: the ability to maintain stable internal conditions 3. Reproduction and Inheritance Sexual reproduction Asexual reproduction

20. Unifying Themes (cont.) 4. Evolution 5. Interdependence of Organisms Ecology: the interaction of organisms with one another and with their environment 6. Matter, Energy, and organization Photosynthesis: captures the energy from the sun into a form of energy that can be used by living things Autotrophs: make their own food Heterotrophs: must take in food to meet energy needs

21. Eight Characteristics of Life  Made of one or more cells  Displays Organization  Grows and Develops  Reproduces  Responds to stimuli  Requires energy  Maintains homeostasis  Adaptations over time

22. Characteristic #1 Made of one or more cells Living things are made of one or more cells. Cells are the basic unit of structure and function in all living things. smallest unit that can carry on the activities of life

23. Characteristic #2 Displays Organization Organisms are highly organized – the basic difference between organisms is the way they synthesize raw materials– cells are like miniature factories. Specialized cells are organized into groups that work together called tissues. Tissues are organized into organs. Organ systems work together to support an organism.

24. Characteristic #3 Grows and Develops Growth results in the addition of mass to an organism and, in many organisms, the formation of new cells and new structures. Develops refers to maturation of the organism

25. Characteristic #4 Reproduces A species is a group of organisms that can breed with one another and produce fertile offspring. Organisms reproduce– this is necessary for the continued existence of the species. In sexual reproduction, 2 cells from different parents unite to produce the first cell of the new organism (offspring & parents have different traits). In asexual reproduction, the new organism has a single parent (offspring & parents have the same traits).

26. Characteristic #5 Responds to Stimuli Anything that is part of the internal or external environments and causes some sort of reaction by the organism is called a stimulus. The reaction to a stimulus is a response

27. Characteristic #6 Requires Energy Living things get their energy from food. Most plants and some unicellular organisms use light energy from the Sun to make their own food and fuel their activities. The ultimate source of energy is the sun Organisms that cannot make their own food get energy by consuming other organisms. Metabolism– sum of chemical building up (anabolism) & breaking down (catabolism)

28. Characteristic #7 Maintains Homeostasis Regulation of an organism’s internal conditions to maintain life is called homeostasis. If anything happens within or to an organism that affects its normal state, processes to restore the normal state begin.

29. Characteristic #8 Adaptations Evolve over time Organisms adjust to their environment– one must adapt to survive – any change in an organism that makes it better suited to its environment is an adaptive response. Variation refers to a set of differences among individuals – sometimes these variations may give the organism an edge over others. Any kind of organism can change, or evolve over time.