1. Nature of Science Unit 1 Scientific Method
History of the Scientific Method
Characteristics of Life
Organization of Living Things
Period 4 stopped here

2. Do you agree or disagree?
Science demands evidence
Science is a social activity
Science is a blend of logic and imagination
Scientific ideas are subject to change
Scientific ideas are durable
Science avoids bias
The natural world is understandable
Tenets. Period 2 stopped here!

3. Review?
5th Period Start here

4. Scientific Method Is there only one “scientific method”?
No. However, they all begin with the identification of a ______________ or a ____________________ to be answered based on observations of the world around us and provide an ________________ method for conducting and analyzing an experiment.
What is a hypothesis?
It is an ________________ ___________ based on observations and your knowledge of the topic.
What is data?
It is __________________ gathered during an experiment.
Question, problem
Organized
Educated guess (or prediction)
Evidence, information, observations

5. Defining the Variables
Independent Variable: what you change, this is what you manipulate
Dependent variable: the factor in an experiment that you want to observe, the data or what you measure
Experimental Group: How will each group be different? (the group exposed to the independent variable)
Control Group: the group that you compare to
No treatment
Constants: the things that stay the same for all the experimental groups

6. Scientific Method Observe, Define the Problem, Develop a Question
Develop a procedure
How will you test your hypothesis? Develop a procedure for a reliable experiment and address safety rules.
(Research) State the Expectations
What do you think will happen? Predict the answer to your question or the outcome of the experiment.
Observe, Define the Problem, Develop a Question
What do you want to know or explain? Use observations you have made to write a question that addresses the problem or topic you want to investigate.

7. Communicate the Results Analyze the Data Perform and Experiment
Write a conclusion that summarizes the important parts of your experiment and the results.
Analyze the Data
Is the data reliable? Does your data and observations from the experiment support your hypothesis?
Perform and Experiment
Follow the steps in your procedure to perform your experiment. Record data and observations!

8. Communicate the Results Analyze the Data Perform an Experiment
Write a conclusion that summarizes the important parts of your experiment and the results.
Is your data inaccurate or the experiment flawed?
Analyze the Data
Is the data reliable? Does your data and observations from the experiment support your hypothesis?
Perform an Experiment
Follow the steps in your procedure to perform your experiment. Record data and observations
Rewrite your procedure
to address the flaws in
the original experiment.

9. We will finish this unit’s notes and work on our virtual seed lab through taking data. I will receive direct instruction on the Nature of Science and Intro to Biology and clear up any confusion on the Virtual Seed Lab.

10. Living vs. Non-Living
Prior to the 1600's many people believed that nonliving things could spontaneously turn into living things. For example, it was believed that piles of straw could turn into mice. That is obviously not the case.

11. Redi’s Experiment on Spontaneous Generation
OBSERVATIONS: Flies land on meat that is left uncovered. Later, maggots appear on the meat.
HYPOTHESIS: Flies produce maggots.
PROCEDURE
Uncovered jars
Covered jars
Controlled Variables:
jars, type of meat,
location, temperature,
time
Several
days pass
Manipulated Variables:
gauze covering that
keeps flies away from
meat
Responding Variable:
whether maggots
appear
Maggots appear
No maggots appear
CONCLUSION: Maggots form only when flies come in contact with meat. Spontaneous generation of maggots did not occur.

12. Spallanzani

13. Pasteur’s Experiment of Spontaneous Generation
Broth is boiled.
Broth is free of
microorganisms
for a year.
Curved neck
is removed.
Broth is
teeming with microorganisms.
Spallanzani was another

14. Pasteur Why did microorganisms grow after Pasteur broke
the neck of the flask?
Biogenesis (generating from life)
All Living things come from other living things!
Spallazani??

15. Key Experiments
Redi began to disprove spontaneous generation, Pasteur came up with the idea of biogenesis

16. Theory: a well tested explanation that unifies a broad range of observations
Can a Theory change over time?
Yes, as new evidence is uncovered, a theory may be revised or replaced
Scientific Theory vs. Scientific Hypothesis

17. Scientific Laws -generalizations derived from facts
Scientific knowledge is based on observation and inference.
Scientific laws describe what happens, but not how or why
Scientific laws are meant to be true for nearly every instance
Scientific laws may occasionally change with new evidence.

18. Characteristics of Living Things
Examples
Living things are made up of units called CELLS.
Many microorganisms consist of only a single cell (unicellular). Animals and trees are multicellular.
Maple trees reproduce sexually. A hydra can reproduce asexually by budding.
Living things reproduce.
Living things are based on a universal genetic code.
Flies produce flies. Dogs produce dogs. Seeds from maple trees produce maple trees.
Living things grow and develop.
Butterflies begin life as eggs, then become caterpillars, and then become adult butterflies.
Living things obtain and use materials and energy.
Plants obtain their energy from sunlight. Animals obtain their energy from the food they eat.
Living things respond to their environment.
Leaves and stems of plants grow toward light.
Living things maintain a stable internal environment.
Start here!
3. DNA
5. Photosynthesis and Respiration
8. Evolution
Despite changes in the temperature of the environment, a robin maintains a constant body temperature.
Taken as a group, living things change over time.
Plants that live in the desert survive because they have become adapted to the conditions of the desert.

19. Important Terms
Metabolism – the set of chemical reactions through which an organism builds up or breaks down materials to carry out life processes
Photosynthesis and Cellular Respiration
Homeostasis – the process by which organisms maintain a relatively stable internal environment
Water concentrations
Evolution – change in an organism over time
Did humans evolve from monkeys?

20. Levels of Organization
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

21. Organism Groups of Cells Molecules Individual living thing Bison
Tissues, organs,
and organ
systems
Smallest functional
unit of life
Groups of atoms;
smallest unit of
most chemical
compounds
Bison
Nervous tissue
Nervous system
Brain
Nerve cell
Water
DNA

22. How to make a wet-mount slide
1 - Get a clean slide and coverslip from your teacher. (hold correctly – by the edges!)
-Place ONE drop of water in the middle of the slide. Don 't use too much or the water will run off the edge and make a mess! Place your specimen in the water drop.
-Place the edge of the cover slip on one side of the water drop.
- Slowly lower the cover sllp on top of the drop.
Cover
Slip
Lower slowly
To supplement before microscope lab!
5 -Place the slide on the stage and view it first with the red-banded objective. Once you see the image, you can rotate the nosepiece to view the slide with the different objectives.
You do not need to use the stage clips when viewing wet-mount slides!