Ms. Moore 1/8/13 Albert Einstein physicist Stephen Hawking cosmology and quantum gravity

 Scientist: a person who is studying or has expert knowledge of one or more of the natural or physical sciences  Who are your favorite scientists?  How many scientists are in this room?

 Science: organized way of using evidence to learn about the natural world  The goal of science is to investigate and understand the natural world, to explain events in the natural world, and to use those explanations to make useful predictions.

 Observation: the process of gathering information about events or processes in a careful, orderly way.  Data: the information gathered from observations. Quantitative data: expressed as numbers, obtained by counting or measuring. Qualitative:  Inference: logical interpretation based on prior knowledge or experience.

 Hypothesis: a proposed scientific explanation for a set of observations. These are generated by scientists using prior knowledge, logical inference, and informed, creative imagination. There can be more than one hypothesis for a question.

 Scientific Method : Asking a Question Forming a Hypothesis Setting up a Controlled Experiment  Controlled experiment: constant  Manipulated/Independent variable: deliberately changed  Responding/Dependent variable: changes in response to manipulation Recording and Analyzing Results  Written records of observations and data. Drawing a Conclusion  Explanation of observations.

 Spontaneous Generation: Francesco Redi Observation: Flies land on meat that is left uncovered, then maggots appear. Hypothesis: Flies produce maggots Procedure: Covered and Uncovered Jars  Controlled variables: jars, type of meat, location, temperature  Manipulated (Independent) variable: gauze covering that keeps flies away from meat  Responding (Dependent) variable: whether maggots appear Conclusion: Maggots form only when flies come in contact with meat. Spontaneous generation of maggots did not occur

 Experiments are often repeated by other scientists to ensure accuracy of experimental procedures and results  A key assumption in science is that experimental results can be reproduces because nature behaves in a consistent manner  Needham vs. Spallanzani Spallanzani improved Needham’s work by observing work of others (Redi); however, air was omitted and could not disprove spontaneous generation. How did Pasteur finally disprove spontaneous generation?

 It is not always possible to do an experiment to test a hypothesis: Ethical issues of humans  Ex: Does this chemical cause cancer in humans? Disruption of a natural system  Ex: How do animals in the wild interact with each other?

 As evidence from numerous investigations builds up, a particular hypothesis may become so well supported that scientists consider it a theory.  In science, theory applies to a well tested explanation that unifies a broad range of observations. Biogenesis: generating from life

 Students will work with lab groups to understand the scientific method.  Each group is assigned a story and they must Ask a question Form a hypothesis Design an experiment  Including all variables that would be tested

 Biology: the science that employs the scientific method to study living things.  What are “living things”? 8 characteristics

 Made up of cells: the smallest unit of an organism that can be considered alive.  Reproduce Sexual reproduction: cells from two different parents unite Asexual reproduction: single parent produces offspring that are identical to itself  Based on a universal genetic code written in DNA  Grow and develop Differentiation: cells begin to look different from one another and perform different functions

 Obtain and use material and energy Metabolism: combination of chemical reactions through which an organism builds up or breaks down material  Respond to their environment Stimuli: a signal to which an organism responds  Living things maintain a stable internal environment Homeostasis: organisms need to keep conditions inside their bodies as constant as possible  Living things evolve

 Molecules: groups of atoms  Cells: smallest functional unit of life  Groups of Cells: tissues, organs, organ systems  Organism: individual living thing  Population: group of organisms of one type that live in the same area  Community: populations that live together in a defined area  Ecosystem: community and its non-living surroundings  Biosphere: the part of Earth that contains all ecosystems  Learn more here! Learn more here!

 Working in pairs, create a “Levels of Organization” presentation using a unique organism. Figure 19 (p.21)  Cover each of the 8 levels in the presentation. You may use a variety of presentations: flip books, comics, posters, etc.  Be prepared to present your creation to the class.

 Most popular system of measurement among scientists: metric system  Metric System: decimal system of measurement whose units are based on multiples of 10

 Length is the distance from one point to another  What can we use to measure length in the lab?  Common Metric Units (meter = slightly longer than a yard) 1 meter (m) = 100 centimeters (cm) 1 meter = 1000 millimeters (mm) 1000 meters = 1 kilometer (km)

 The amount of matter in an object is defined as mass.  How could we measure mass in lab?  Common Metric Units (1 gram = 1 paperclip) 1 kilogram (kg) = 1000 grams (g) 1 gram = 1000 milligrams (mg) 1000 kilograms = 1 metric ton (t)

 Volume is the amount of space an object takes up.  How is volume measured?  Common Metric Units 1 liter (L) = 1000 milliliters (mL) 1 liter = 1000 cubic centimeters (cm 3 )

 Temperature is used to measure hotness or coldness.  How is temperature measured?  Common Metric Units 0°C = freezing point of water 100°C = boiling point of water

 2.54 centimeters (cm) = 1 inch (in.)  1 meter (m) = inches (in.)  1 kilometer (km) = 0.62 miles (mi)  1 liter (L) = 1.06 quarts (qt)  236 milliliters (mL) = 1 cup (c)  1 kilogram (kg) = 2.2 pounds (lb)  28.3 grams (g) = 1 ounce (oz)  ° C = 5/9 x ( ° F – 32)

 What methods of recording data are utilized in science?  How can these tools help biologists analyze data quickly?

 Microscopes are devices that produce magnified images of structures that are too small to see with the unaided eye  Types: Light microscopes: produce magnified images by focusing visible light rays Electron microscopes: produce magnified images by focusing beams of electrons

 Light microscopes can produce clear images of objects at a magnification of about 1000X  Compound light microscopes: allow light to pass through the specimen and use two lenses to form an image  Used to observe dead organisms and cells while they are still alive.

 Electron microscopes are used for objects smaller than 0.2 micrometers (1/50 the diameter of a typical cell)  Electron microscopes can produce images almost 1000X more detailed than light microscopes  Types: Transmission electron microscopes (TEMs): shine a beam of electrons through a thin specimen; give great detail inside the cell Scanning electron microscopes (SEMs): scan a narrow beam of electrons back and forth across the surface of a specimen; produce a realistic, 3D image of the surface of objects

 Cell cultures: cell is placed into a nutrient solution to replicate from a single original cell  When would we use cell cultures?  Cell fractionation: separate cell parts Disrupt membrane and release parts Add liquid and transfer into centrifuge Most dense parts of cell are now in the bottom and a biologist can remove the specific part based on density

 Using the knowledge we learned today, complete the worksheet using lab materials supplied at your table.  Who has bigger hands: practice with the scientific method