Presentation on theme: "Biology. The Science of Biology Chapter 1 1-1 What Is Science?"— Presentation transcript:
The Science of Biology Chapter 1
1-1 What Is Science?
Learning Targets Sections 1-1and 1-2 Explain the goals of science Explain what a hypothesis is and give examples List and explain the steps of the scientific method
What is Science? Science: A systematic way of learning about the world The goal of science is to…. –Investigate & Understand nature –Explain events in nature –Make predictions based on explanations The goal of technology is… –to use science to improve our daily lives
What is Biology? Break It Down: –Bio: Life or living organism –Logy: The study of –Examples of words with Bio- in them? With –logy in them?
Themes of Biology Two Main Themes of Biology: –Shared Properties of Living Things/Life What we will be learning 1st semester »Biochemistry »Cells »Genetics –Diversity of Living Things/Life
Diversity of Life
Me, A Scientist? Science is asking questions about nature and investigating to try to find “answers” Remember: One of our first goals of science was to try to understand nature Answers are not always achieved, logical explanations are found Examples in your life where you may act as a scientist
What Is My Job? Scientists seek proof, or explanations for things occurring in nature These explanations are often used to build predictions (another goal of science) –What is the method called that scientists use to come up with these reasonable explanations?
–A series of steps scientists use to help solve a problem –Can be used by all people and for all problems –Steps: 1.Observations 2.State the problem 3.Make a testable hypothesis 4.Experimentation- (Designing & Complete) 5.Data- Record and Analyze 6.Form a conclusion 7.Repeat and publish results
Let’s Create a Mnemonic Device This HAS to be in order: 1.O________________ 2.S ________________ 3.H________________ 4.E ________________ 5.D________________ 6.C________________ 7.R________________
1. Observations Observe the world around you/sometimes called research –Involves using the 5 senses –Keep an open mind with no conclusions Information gathered from observations is called evidence
Observations, cont’d. TWO TYPES: –Quantitative Observation: Deals with numerical values or a quantity Example: The dog weighs 55 pounds –Qualitative Observation: Usually does not involve a numerical value but rather a descriptive statement. Example: The dog is heavy.
1–1 –Observations involving numbers are known as A)qualitative observations. B)hypothetical observations. C)quantitative observations. D)inferred observations.
Interpreting Evidence Inference is a logical interpretation based on prior knowledge and experience. Not necessarily based on fact or experimental data. Inferences are formed after observations have been made
1–1 –A scientist takes paint chips from 10 apartments in a large building. She tests for the presence of lead in the paint and finds it in all 10 samples. She then concludes that lead paint is probably present in all 120 apartments in the building. This conclusion is an example of A) a scientific fact. B) a scientific error. C) proof. D) a reasonable inference.
StatementObservationInference Object A is round and orange. Object A is a basketball. Object C is round, black and white. Object C is larger than Object B. Object B is smooth. Object B is a table-tennis ball. Each object is used in a different sport. What is Object C? What type of observations are these? X X X X X X X Soccer Ball Qualitative
Let’s practice inferences
2. State the Problem Identify the problem to study Based on observations, curiosity and past experiences –Ex: Is it living or non-living?
3. Form a testable Hypothesis Where do hypotheses come from? –Prior Knowledge –Logical Inferences –Imaginative Guesses
Hypotheses, cont’d. Form a Hypothesis: –Attempts to explain the event before facts are gathered and tested –Must be testable!!! Should contain “If” and “Then” Ex: If skin cancer is related to ultraviolet light, then people with a high exposure to UV light will have a higher frequency of skin cancer.
Try writing your own hypothesis Use the following problem to come up with a hypothesis and write it down in your notes. Problem: The leaves on one of your house plants are turning yellow. The plant gets plenty of sunlight and water, but it is located in front of a drafty window where it gets very cold.
4. Experimentation Determine if the hypothesis is correct –Repeat experiments many, many times –Accuracy of results depends on amount of data collected –Only change one variable at a time, keep all others controlled
Experimentation, cont’d. Two parts to an experiment: –Control: the part of the experiment that stays the same –Variable: the part of the experiment that is being tested Independent Variable/Manipulated Variable –The variable that scientists deliberately change –Graphed on the X-axis Dependent Variable/Responding Variable –The variable that changes in response to the manipulated variable –Graphed on the Y-axis
OBSERVATIONS: Flies land on meat that is left uncovered. Later, maggots appear on the meat. HYPOTHESIS: Flies produce maggots. PROCEDURE Controlled Variables: jars, type of meat, location, temperature, time Manipulated Variables: gauze covering that keeps flies away from meat Uncovered jarsCovered jars Several days pass Maggots appearNo maggots appear Responding Variable: whether maggots appear CONCLUSION: Maggots form only when flies come in contact with meat. Spontaneous generation of maggots did not occur. Redi’s Experiment
Apply It! Redi’s Experiment Observations: Flies land on meant that is left uncovered. After time, maggots appear on the meat. Hypothesis: Flies produce maggots. Controlled Variables: jars, types of meat, location, temperature, time Manipulated Variables: Gauze covering that keeps flies out of jars, away from meat Responding Variables: Whether maggots appear or not Conclusion: Maggots only form when flies come in contact with meat. There is no spontaneous generation of maggots.
5. Data- Record and Analyze Written records of their observation during the experiments (data) –Measurements (numbers, tick marks, etc.) –Observations (statements, notes, etc.) Graphs, charts are developed to show relationships within the data
Bell Ringer 8/22 Without using your notes try to answer the following questions in your science journal. What is the goal of science? What is a hypothesis and in what form should it presented? List the steps of the Scientific Method. (Use your mnuemonic)
Graphing Criteria Things to do when graphing: –Title –Label X and Y axis with variable label and units Numbering interval on each axis must be uniform –Points are plotted neatly –“Best Fit” line for linear data, or smooth curves for other data –Must be neat and legible –Use entire sheet of graph paper
Line Graphs: –Frequently used in science –X axis always contains the independent or manipulated data –Y axis contains the dependent or responding variable. –Multiple related data sets can be graphed on one graph Must use a legend or key Use different colors or line types Types of Graphs
Types of Graphs, cont’d. Bar Graphs: –Bar graphs are simplified versions of a line graph –Bar graphs are most often used in business and in media (they are easier to read)
Cupcakes Eaten per Minute Cupcakes Eaten, (#)
Type of Graphs, cont’d. Pie Charts: –Pie charts are used to show percentages –Remember: Sample / Total X 100 = %
Body Fat % in Men 25-40 Yrs. Old
Data Analysis Data Table: –Title on the table –Identify X and Y variable including units –Data collected in ordered pairs –Neat
The Change in Temperature Over Time Time minutes 0 1 2 3 4 5 6 7 8 9 10 Temp. C 20 21 23 27 35 45 61 69 71 73 74
Let’s practice graphing
6. Come to a Conclusion The summary of all the information gathered in an experiment Restates the hypothesis Identifies if the hypothesis was accepted or rejected Will identify at least 3 errors to the experiment
A key assumption in science is that experimental results can be reproduced. Therefore, scientists test one another’s investigations –Your procedure needs to be able to be reproduced—your conclusion will not be accepted if it cannot be reproduced 7. Repeat and Publish Investigations
Fact, Theory, and Law Fact –A known truth about something –Ex: It is 85° outside Theory –The most logical explanation for an event in nature –Based on careful observation and analysis –Must be dependable and reproducible Ex: The World is Flat Law –Describes an event –Summarizes repeated observations –Ex: Newton’s 3 rd Law of Motion
A Scientific View of the World Scientists assume the universe obeys certain rules and those rules can be discovered and understood A good scientist should be curious, open minded, honest, and skeptical
The Study of Living Things Characteristics of Life in the Scientific World
Learning Targets Section 1-3: Studying Life List and describe the characteristics of living things Describe how life can be studied at different levels. Distinguish between living and non-living things
What is Biology? We determined early in Chapter 1 that… BIO means… LOGY means… Biology studies the living world –Using the Scientific Method
Characteristics of Living Things Biologists still debate today what it takes to constitute a living thing MOST agree that there are 8 characteristics that are common to living things
8 Common Characteristics Living Things… Are made up of CELLS REPRODUCE Based on a universal GENETIC CODE GROW AND DEVELOP OBTAIN and USE materials and ENERGY RESPOND to their environment MAINTAIN stable living ENVIRONMENT As a group, CHANGE OVER TIME
Lets Think of a mneumonic Device This one does not have to have a specific order! Be creative! Use the letters: C, R, G, G, E, R, M & C
Living Things: Made of CELLS Cell: collection of living matter enclosed by a barrier that separates the cell from its surroundings Cells are the smallest units of an organism that can be considered alive Complex and highly organized Unicellular vs. Multicellular Human Red Blood Cells
Living Things: REPRODUCE Two Basic Kinds of Reproduction: –Sexual Reproduction Two cells from different parents produce first cell of new organism Most multicellular organisms produce this way –Asexual Reproduction New organism is produced by a single parent In some cases, a single-celled organism will divide in half to form two new organisms Other times, a new organism can grow out of (or split off from) the existing organism--Budding
Living Things: Based on a GENETIC CODE Offspring usually resemble their parents –In Asexual Reproduction, offspring and parents have the exact same traits –In Sexual Reproduction, offspring differ from their parents (in limited ways)
Living Things: Genetic Code Directions for inheritance are carried by DNA (Deoxyribonucleic acid) –With minor exceptions, DNA genetic code determines the inherited traits of EVERY organism on Earth!
Living Things: Grow and Develop
Living Things: GROW AND DEVELOP Every organism has a distinct life cycle—there is a set pattern of growth and change that occurs All organisms grow during at least part of their lives (increase in size) Multicellular organisms’ life cycles involve a process called development—cells increase in number and differentiate Development is LIMITED OR NON-EXISTENT in unicellular organisms
THINK- PAIR- SHARE THINK- Close your notes and think about the four characteristics of life we just discussed. PAIR- Turn to your partner and see if you can list them and explain what they mean. SHARE- You and your partner pair up with another group and share what you know about the four characteristics we just learned.
Living Things: OBTAIN AND USE ENERGY Organisms take in selected materials they need from their surroundings (environment)—BUT the way that they obtain energy varies –Plants from Sunlight, Sheep from Plants, etc. –Decomposers from remains of dead organisms Metabolism: Combination of chemical reactions through which organisms build up or break down materials required for life processes
Living Things: OBTAIN AND USE ENERGY
Living Things: RESPOND TO ENVIRONMENT Necessary because organisms live in constantly changing environments (light, temperature, etc) Each organism responds to the environment in their own way Some slow, some fast EX: New leaves and stems growing from a tree grow towards light
Living Things: RESPOND TO ENVIRONMENT
Living Things: Maintain Stable Internal Environment HOMEOSTASIS: Process by which organisms keep their internal environments relatively stable Ex: Plants can take in and give off water as needed If homeostasis is disrupted in a major way, the organism cannot survive
Living Things: CHANGE OVER TIME Basic traits of organisms stay the same over their lifetime Groups of organisms change over time, or EVOLVE –Occurs over hundreds of thousands or even millions of years, not just a few generations –Usually in response to changes in their environments Organisms naturally make changes over time to increase the species’ chances of survival
Living Things: Change Over Time
THINK PAIR SHARE THINK- Close your notes and think about the four characteristics of life we just discussed. PAIR- Turn to your partner and see if you can list them and explain what they mean. SHARE- Share with each other why it might be important for us to make a list of qualities that living things must share.
Concept Check Using what you know so far explain in your science journal how the following pictures exhibits all of the characteristics of living things TURN IN YOUR RESPONSE
BRANCHES OF BIOLOGY Biology is often organized into branches –Some divisions are based on the type of organism being studied Zoologists (study animals) Botanists (study plants) Ethologists (study animal behavior) –Some divisions are based on the idea that life can be studied at different levels of organization -Molecules-Populations -Cells-Communities -Groups of Cells-Ecosystems -Organisms-Biospheres
Biosphere Ecosystem Community Population The part of Earth that contains all ecosystems Community and its nonliving surroundings Populations that live together in a defined area Group of organisms of one type that live in the same area Biosphere Hawk, snake, bison, prairie dog, grass, stream, rocks, air Hawk, snake, bison, prairie dog, grass Bison herd Levels of Organization Go to Section:
Organism Groups of Cells Molecules Individual living thing Tissues, organs, and organ systems Smallest functional unit of life Groups of atoms; smallest unit of most chemical compounds Nervous tissueNervous systemBrain Nerve cell Water DNA Go to Section: Bison
HOW DOES BIOLOGY AFFECT ME? More than any other science, Biology helps you understand what affects the quality of your life –What DOES affect the quality of your life?
1-4 Tools and Procedures
Describe the measurement system most scientists use, and be able to make conversions Understand why it is necessary for scientists to use the same measurement system Explain how light microscopes and electron microscopes are similar and different Learning Targets Section 1-4: Tools and Procedures
Common Measurement System THE METRIC SYSTEM –The metric system is the most widely used system of measurement in the world –The United States is one of the two countries in the world that does not use the metric system (Burma is the other) –System International is the governing body for the metric system (SI) –The metric system is based on units of 10
Why the Same System? Scientists need a common system of measurement to be able to replicate others’ experiments, so they use the metric system when collecting DATA
Common Metric Units Length-meter (m)Mass- gram (g) 1 meter = 100 centimeters (cm) 1 meter = 1000 millimeters (mm) 1000 meters = 1 kilometer (km) 1 kilogram (kg) = 1000 grams 1 gram = 1000 milligrams (mg) 1000 kilograms (kg) = 1 metric ton (t) Volume-liter (L)Temperature-Celsius (°C) 1 liter = 1000 milliliters (mL) 1 liter = 1000 cubic centimeters (cm 3 or cc) 0°C= freezing point of water 100 ° C = boiling point of water
Metric Line Kiss Him/Her Dummy But Don’t Catch Mono Base units: –Meter (m) –Liter (L) –Gram (g) k H D base unit d c m
Metric Conversions Metric Line Place finger on starting prefix Place 2 nd finger on ending prefix Count the lines between fingers Move the decimal place the # of lines toward the 2 nd finger Add zeros to hold place k H D base unit d c m
Convert the following: 1 km = ________ m 12 mm = _______ cm 4.2 L = _______ mL Answers: 1 km = 1000 m 12 mm = 1.2 cm 4.2 L = 4200mL
Microscopes Devices that produce magnified images of things too small to see with the unaided eye Two types –Light microscope –Electron
Compound Light Microscopes Magnify images by focusing visible light rays Advantage: view living things Disadvantage: Resolution limit is only 1000X
Electron Microscopes Magnify images by focusing electrons Advantage: higher resolution limit, about 100,000X normal size –100X higher than a light microscope Disadvantage: Organisms must be stained and are in a vacuum (cannot view live specimens)
Two Types of Electron Microscopes Scanning electron microscopes (SEM) –Takes a 3-D view of the surface Transmission electron microscopes (TEM) –Beam of electrons passes through a thin slice –Specimens must stained and sliced
According to the Video… On a sheet of paper, give me the two ways that Light Microscopes differ from Electron Microscopes TURN IT IN!
Laboratory Techniques for Studying Cells Cell Cultures –Grow cells in dish from a single organism –Used to Test cell responses under controlled conditions Study interactions between cells Select specific cells for further study
Laboratory Techniques for Studying Cells, cont’d. Cell Fractionation –Method of separating the pieces of broken cells Steps –Break cells apart –Add liquid and mix –Centrifuge to separate by mass (spin very fast)
Cell Fractionation Biologists can remove specific parts to be studied by selecting layer.
1–1 –Which of the following shows the interaction of science and human values? the debate over the best way to produce electricity investigating how a manatee behaves Determining what causes a disease using a hypothesis to test an explanation
1–1 –A possible explanation for a set of observations is known as data. a hypothesis. an inference. a result.
1–1 –A good scientific hypothesis must be correct. able to be tested. obvious. based on common sense.
1–2 –In an experiment, the variable that is deliberately changed is called the control. manipulated variable. responding variable. constant control
1–2 –The mistaken belief that living organisms can arise from nonliving matter is called biogenesis. Pasteur's theory. spontaneous generation. Spallanzani’s hypothesis.
1–2 –Which of the following was the manipulated variable in Redi’s experiment? the kind of meat used the temperature the jars were kept the gauze covering on some jars the kind of fly that visited the jars
1–2 –A well-tested explanation that unifies a broad range of observations is a hypothesis. variable. control. theory.
1–2 –A scientific explanation does not become a theory until a majority of scientists agree with it. it has been supported by evidence from numerous investigations and observations. it is first proposed as an explanation. it is published in a textbook.
1-3 –An increase in size is known as growth. metabolism. development. differentiation.
1-3 –Which of the following is NOT a characteristic of all living things? use of energy made of cells stable internal environment need for oxygen
1-3 –Which of the following are branches in the study of biology? cells, tissues, organs, and organisms botany, cell biology, ecology, and zoology populations, communities, and ecosystems the genetic code, evolution, and the biosphere
1-3 –The genetic code is carried in a.Water. b.DNA. c.proteins. d.soil.
1-3 –Which of the following shows the levels of organization in correct order from the simplest to the most complex? organisms, cells, populations, molecules, ecosystems ecosystems, populations, organisms, cells, molecules molecules, cells, organisms, populations, ecosystems molecules, organisms, cells, populations, ecosystems
1-4 –A single measurement system is commonly used in science because it allows scientists to easily replicate one another’s experiments. basic units of mass, length, and volume are unrelated to one another. more kinds of measurements can be made. computers can store large amounts of scientific data.
1-4 –Compared to a light microscope, an electron microscope is used to observe larger objects with less detail. larger objects with more detail. smaller objects with more detail. smaller objects with less detail.
1-4 –A device that separates cell parts is a centrifuge. cell culture. light microscope. electron microscope.
1-4 –A technique in which cells are grown in a nutrient solution is known as staining. cell fractionation. cell culturing. cell fertilizing.
1-4 –When you work in a biology laboratory situation, your first priority should be to make sure all materials are available. modify any instructions that do not make sense. familiarize yourself with all safety rules before beginning to work. know ahead of time what kinds of results to expect.