1. What Science Is and Is Not
What is the goal of science?

2. What Science Is and Is Not
The goal of science is to:
investigate and understand the natural world
explain events in the natural world
use those explanations to make useful predictions

3. What Science Is and Is Not
Science is an organized way of using evidence to learn about the natural world. The word science also refers to the body of knowledge that scientists have gathered.

4. Scientific Method Observation Hypothesis Experiment Data
Analysis/Conclusions
Theory

5. Scientific Method 1. Observation
Scientific thinking begins with observation (the process of gathering information about events or processes in a careful, orderly way).

6. 1. Observation continued…
Scientific Method
1. Observation continued…
The information gathered from observations is called data.
Quantitative data are expressed as numbers, obtained by counting or measuring.
Qualitative data are descriptive and involve characteristics that can’t easily be measured.

7. 1.Observation continued…
Scientific Method
1.Observation continued…
Scientists use data to make inferences.
An inference is a logical interpretation based on prior knowledge or experience.
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8. Scientific Method 2. Hypothesis
A hypothesis is a proposed scientific explanation for a set of observations.
“Educated guess” as to why.
A hypothesis may be ruled out or confirmed by performing controlled experiments or by gathering new data

9. More later about designing experiments……
Scientific Method
3. Experiment
Experiments must have only 1 variable that is changed to have valuable results.
Manipulated/Independent Variable
Responding/Dependent Variable
More later about designing experiments……

10. Scientific Method 4. Data
Scientists record data, findings, information (quantitative and/or qualitative) from their experiments.
They analyze this data to make conclusions.

11. Scientific Method 5. Analysis/Conclusion
Researchers often work in teams to analyze, review, and critique each other’s data and hypotheses.
A review process helps ensure conclusions are valid.
To be valid, a conclusion must be based on logical interpretation of reliable data.

12. Scientific Method 6. Theory
Hypotheses that have been tested and retested by several scientists can be agreed upon as a theory, rather than an idea/hypothesis.
This takes a lot of evidence and usually a lot of time in order for the majority to agree.
Theories are not facts, however because they can change if further evidence proves them incorrect.

13. Science as a Way of Knowing
Science is an ongoing process that involves:
asking questions
observing
making inferences
testing hypotheses

14. Science as a Way of Knowing
Scientific understanding is always changing.
Good scientists are skeptics who question both existing ideas and new hypotheses.

15. Science and Human Values
Decisions involve many factors besides scientific information, including:
the society in which we live
economic considerations
laws
moral principles
Citizens decide what to do when they vote.

16. 1-2 How Scientists Work

17. Designing an Experiment
a hypothesis should be tested by an experiment in which only one variable is changed at a time. All other variables should be controlled.
The process of testing a hypothesis includes:
Asking a question
Forming a hypothesis
Setting up a controlled experiment
Recording and analyzing results
Drawing a conclusion

18. Designing an Experiment
manipulated variable – (independent) variable that is deliberately changed
responding variable – (dependent) variable that is observed after/because of the change

19. Redi’s Experiment
In a controlled experiment, only one variable is tested at a time. Redi designed an experiment to determine what caused the sudden appearance of maggots. In his experiment, the manipulated variable was the presence or absence of the gauze covering. The results of this experiment helped disprove the hypothesis of spontaneous generation.

20. Repeating Investigations
Scientists repeat experiments to be sure that the results match those already obtained.
Needham's Test of Redi's Findings
Needham challenged Redi’s results by claiming that spontaneous generation could occur under the right conditions.

21. Repeating Investigations
Needham’s Test of Redi’s Findings
Needham sealed a bottle of gravy and heated it.
After several days, the gravy was swarming with microorganisms.
Needham concluded that these organisms came from the gravy by spontaneous generation.

22. Spallanzani's Test of Redi's Findings
Spallanzani did not believe that Needham had heated his samples enough!
Spallanzani’s experiment showed that microorganisms will not grow in boiled gravy that has been sealed but will grow in boiled gravy that is left open to the air. Interpreting Graphics What variable was controlled in this experiment?

23. Repeating Investigations
Pasteur's Test of Spontaneous Generation
Louis Pasteur conclusively disproved the hypothesis of spontaneous generation.

24. When Experiments Are Not Possible
It is not always possible to do an experiment to test a hypothesis. For example:
Wild animals must be observed without disturbing them.
Ethical considerations prevent some experiments.

25. How a Theory Develops How a Theory Develops
As evidence from numerous investigations builds up, a hypothesis may become so well supported that scientists consider it a theory.
In science, the word theory applies to a well-tested explanation that unifies a broad range of observations.
No theory is considered absolute truth.
As new evidence is uncovered, a theory may be revised or replaced by a more useful explanation.

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1-3 Studying Life
Photo Credit: © Andrew Syred/Science Photo Library/Photo Researchers, Inc.
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27. Characteristics of Living Things
What are some characteristics of living things?
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28. Characteristics of Living Things
No single characteristic is enough to describe a living thing.
Some nonliving things share one or more traits with living things.
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29. Characteristics of Living Things
Living things share the following characteristics:
made up of units called cells
reproduce
based on a universal genetic code
grow and develop
obtain and use materials and energy
respond to their environment
maintain a stable internal environment
change over time
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30. Characteristics of Living Things
Living things are made up of cells.
A cell is the smallest unit of an organism that can be considered alive.
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31. Characteristics of Living Things
Living things reproduce.
In sexual reproduction, cells from two different parents unite to form the first cell of the new organism.
In asexual reproduction, a single parent produces offspring that are identical to itself.
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32. Characteristics of Living Things
Living things grow and develop.
During an organism’s development, cells differentiate, which means that the cells look different from one another and perform different functions.
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33. Characteristics of Living Things
Living things are based on a universal genetic code.
Organisms store the information they need to live, grow, and reproduce in a genetic code in a molecule called DNA.
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34. Characteristics of Living Things
Living things obtain materials and use energy.
The combination of chemical reactions through which an organism builds up or breaks down materials is called metabolism.
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35. Characteristics of Living Things
Living things respond to their environment.
A stimulus is a signal to which an organism responds.
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36. Characteristics of Living Things
Living things maintain a stable internal environment.
Although conditions outside an organism may change, conditions inside an organism tend to remain constant.
This process is called homeostasis.
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37. Characteristics of Living Things
Taken as a group, livings things change over time. Over many generations, groups of organisms typically evolve.
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38. Interdependence in Nature
Big Ideas in Biology
Interdependence in Nature
All forms of life on Earth are connected together into a biosphere, which literally means “living planet.”
The relationship between organisms and their environment depends on both the flow of energy and the cycling of matter.
Everything depends on everything to live!!!
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Big Ideas in Biology
Matter and Energy
Life’s most basic requirements are matter that serves as nutrients to build body structure and energy to fuel the processes of life.
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Big Ideas in Biology
Cellular Basis of Life
Organisms are composed of one or more cells, which are the smallest units that can be considered fully alive.
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41. Information and Heredity
Big Ideas in Biology
Information and Heredity
Life’s processes are directed by information carried in a genetic code that is common, with minor variations, to every organism on Earth.
That information, carried in DNA, is copied and passed from parents to offspring.
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42. Unity and Diversity of Life
Big Ideas in Biology
Unity and Diversity of Life
All living things are fundamentally alike at the molecular level, even though life takes an almost unbelievable variety of forms.
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Big Ideas in Biology
Evolution
In biology, evolution, or the change in living things through time, explains inherited similarities as well as the diversity of life.
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44. Structure and Function
Big Ideas in Biology
Structure and Function
Structures evolve in ways that make particular functions possible, allowing organisms to adapt to a wide range of environments.
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Big Ideas in Biology
Homeostasis
An organism’s ability to maintain a relatively stable internal environment in the face of changing external conditions is vital to its survival.
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46. Science, Technology, and Society
Big Ideas in Biology
Science, Technology, and Society
Science seeks to provide useful information, but only a public that truly understands science and how it works can determine how that information should be applied.
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Branches of Biology
Branches of Biology
There a many branches of biology.
For example:
Zoologists study animals.
Botanists study plants.
Paleontologists study ancient life.
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Branches of Biology
How can life be studied at different levels?
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Organization of Life
Life is organized into several levels.
Atoms (O, C, N, H, etc.)
Molecules (H20, DNA, etc.)
Cells (Smallest unit of LIFE)
Tissues (Collection of cells)
Organs (Collection of Tissues)
Organ Systems (Organs with a common purpose)
Organisms (One body of life in a species that is fully functional)
Populations of a single kind of organism (aka Species)
Community of different organisms in an area (Different Species)
Ecosystem (biotic/living and abiotic/nonliving parts)
Biosphere (earth)
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Biosphere
The part of Earth that contains all ecosystems
Living things may be studied on many different levels. The largest and most complex level is the biosphere. The smallest level is the molecules that make up living things.
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Ecosystem
Community and its nonliving surroundings
Living things may be studied on many different levels. The largest and most complex level is the biosphere. The smallest level is the molecules that make up living things.
Hawk, snake, bison, prairie dog, grass, stream, rocks, air
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Community
Populations that live together in a defined area
Living things may be studied on many different levels. The largest and most complex level is the biosphere. The smallest level is the molecules that make up living things.
Hawk, snake, bison, prairie dog, grass
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Population
Group of organisms of one type that live in the same area
Living things may be studied on many different levels. The largest and most complex level is the biosphere. The smallest level is the molecules that make up living things.
Bison herd
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Organism
Individual living thing
Living things may be studied on many different levels. The largest and most complex level is the biosphere. The smallest level is the molecules that make up living things.
Bison
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Groups of Cells
Tissues, organs, and organ systems
Living things may be studied on many different levels. The largest and most complex level is the biosphere. The smallest level is the molecules that make up living things.
Nervous tissue Brain Nervous system
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Cells
Smallest functional unit of life
Living things may be studied on many different levels. The largest and most complex level is the biosphere. The smallest level is the molecules that make up living things.
Nerve cell
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Molecules
Groups of atoms; smallest unit of most chemical compounds
Living things may be studied on many different levels. The largest and most complex level is the biosphere. The smallest level is the molecules that make up living things.
Water DNA
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58. Tools and procedures Metric system - international Microscopes
Compound Light Microscope – light and mirrors
Electron microscope – electrons and magnets
Technique
Cell culture – Growing cells from one cell in a dish
Cell fractionation – Separating parts of a cell by spinning it
Work Safe
Follow all teacher instructions

59. Biology in Everyday Life
More than any other area of study, biology touches your life every day.
Biology provides information about the food you need and the methods for sustaining the world’s food supplies.
Biology describes the conditions of good health and the behaviors and diseases that can harm you.
Biology is used to diagnose and treat medical problems.
Biology identifies environmental factors that might threaten you.
Biology helps you understand what effects the quality of your life.
Biology provides decision makers with useful information and analytical skills needed to predict and effect the future of the planet.
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