Post on 05-Dec-2021
Intro
• All of my powerpoints, notes, and most handouts can be found on my website at
www.bohneoprfhs.weebly.com - please use this website regularly as it is always updated!
• My website is what you should turn to if you lose something or forget what your HW is, OR….if you are absent!!!
Science
• Goals are to investigate and understand the natural world, to explain events in the natural world, and to use those explanations to make useful predictions
Biology
• Study of life
• Important b/c many of the advances in science and their social implications are related to biology
• How do you use it every day?
Science and Society
• Science must take societal issues into account.
• Biology plays a major role in the research, development, and production of food, medicine, and other consumer items.
Applications of Biology
• Human biology – sleeping rhythms, basic needs of the body
• Global ecology – oil spills, global warming
• Biotechnology-changes in DNA/proteins
• Environmental biology- nature
• Can you think of other applications?
Branches of Biology
• Anatomy
• Botany
• Cell biology
• Conservation biology
• Ecology
• Genetics
• Marine biology
• Pathology
• Zoology
Central Themes in Biology • Cellular basis of life • Information and heredity • Matter and energy • Growth, development, and reproduction • Homeostasis • Evolution • Structure and function • Unity and Diversity of Life • Interdependence in nature • Science as a way of Knowing
Biology and Current Events • Human Genome Project
• Viruses
• Environment
• http://www.biologynews.net/
• http://www.macroevolution.net/biology-current-events.html#.UhFVmDYo4qU
Science is a METHOD
• Understanding the natural world using observations and experimentation.
• To be useful, results must be repeatable and verifiable by other scientists
Pseudoscience • The word “pseudo” means fake, and the surest way
to spot a fake is to know as much as possible about the real thing….science
• False science • Pseudoscience cannot be investigated and explained
in terms we can understand. • The primary goal of science is to achieve a more
unified understanding of the physical world/pseudosciences are more likely to be driven by ideological, cultural, or commercial goals
• Ex: astrology, UFO-ology, creationism
Scientific Method
1. Observe and state a problem
2. Form a testable hypothesis
3. Design and conduct an experiment
4. Collect Data
5. Draw a Conclusion
Observe and State a Problem
• Observation uses all of the senses. Different than an inference (an assumption based off of an observation).
• 2 types of observations: Quantitative and Qualitative
• Quantitative = observations that involve numbers (there are 24 students in class)
• Qualitative = observations that involve description (most students are wearing red)
Scientific Observations
• The green sea turtle laid 286 eggs, 250 hatched, and 120 hatchlings survived.
• The red eyed tree frog has pronounced nuptial pads on his hind legs.
• Scientists use all of their senses to make observations.
Hypothesis
• A solution to a problem
• Must be testable
• Predicts an outcome
• Often seen as an “if…then…because” statement
• Example: If I add Miracle Grow to a plant then it will grow taller because the plant will have more nutrients to utilize.
Scientific Theory
• Model that is supported by
data from many testable hypotheses and for
which little, if any, opposing data have been
found.
• Ex: theory of evolution
• Make predictions from
a theory (ex: there should be
Observable differences and similarities between modern organisms and fossils found in rocks).
Theory of Evolution
• There is variation in all
populations of organisms.
• The env. interacts with the population in a way that individuals better adapted to the env. will produce more offspring than those who are less fit.
• Overtime this natural selection produces organisms well suited to their env.
How Charles Darwin used methods of
science… • Darwin made observations during his travels.
• He developed a hypothesis of how species change over time.
• He examined his data to see whether or not they supported the hypothesis
• After more study he concluded that evolution occurs and published his results.
Experiment
• Is a procedure to test the hypothesis
• A variable is any factor that can change in an experiment
• A good/valid experiment changes only ONE variable at a time so you know which variable is responsible for your results.
• An experimenter changes ONE factor and then observes and records what happens
A Controlled Experiment
• Has 2 groups: The control group and the experimental group
• Both groups are set up exactly the same except you change ONE factor (or variable) in the experimental group. Control give you something to compare the experimental group to.
Variables
• Dependent Variable: The variable that is observed and changes because of the manipulated (independent) variable in an experiment (also called responding variable)
• Independent Variable: the variable that is changed by the scientist(also called manipulating variable)
Miracle Grow experiment
Adding the Miracle Grow
independent variable
Growth rate of plants
dependent variable
Plant with Miracle Grow:
experimental group
Plant without Miracle Grow:
control group
Repeat, Repeat, Repeat
• The best experiments make several trials with the independent variable
Data
• The results of your experiment may have two types of data
▫ Quantitative
▫ Qualitative
Data should always be organized
Organize data as charts, tables, or graphs
Graphs
• Can make patterns and trends in data easier to recognize and understand.
• Rules of Graphing:
▫ Label each axis and include units
▫ Independent variable goes on X axis
▫ Dependent variable goes on Y axis
▫ Each interval should be equal
▫ Include a DESCRIPTIVE title
Axes? Independent variable? Dependent variable?
Identify a data point
What are the increasing and decreasing trends? Draw a conclusion
Conclusion
• After you analyze your data, you can come up with your conclusion
• The conclusion will support or reject your hypothesis
• Then you should retest your experiment!
Summary of the SM
1) State Observations about a problem you’ve identified
2) Form a Hypothesis about the problem (if…then…)
3) Design an Experiment to test the hypothesis
4) Collect Data
5) Form a Conclusion
6) Retest
Modeling
• Can you explain what is happening in this diagram?
What is happening in this diagram?
Metric System
• Developed by the French in the late 1700’s.
• Based on powers of ten, so it is very easy to use.
• Used by almost every country in the world, with the notable exception of the USA.
• Especially used by scientists.
• Abbreviated SI, which is French for Systeme International.
Metric Prefixes
• Regardless of the unit, the entire metric system uses the same prefixes.
• Common prefixes are:
kilo = 1000
centi = 1/100th
milli = 1/1000th
1 meter = 100 centimeters= 1000 millimeters
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Length
• Length is the distance between two points.
• The SI base unit for length is the meter.
• We use rulers or meter sticks to find the length of objects.
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Mass • Mass is the amount of matter that makes up an object.
• A golf ball and a ping pong ball are the same size, but the golf ball has a lot more matter in it. So the golf ball will have more mass.
• The SI unit for mass is the gram. • A paper clip has a mass of about one gram. • The mass of an object will not change unless we add or subtract matter from it.
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Measuring Mass
• We will use a electronic balance to measure mass.
• Gravity pulls equally on both sides of a balance scale, so you will get the same mass no matter what planet you are on.
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Weight
• Weight is a measure of the force of gravity on an object.
• Your weight can change depending on the force of gravity. The gravity will change depending on the planet you are on.
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Volume • Volume is the amount of
space contained in an object.
• We can find the volume of box shapes by the formula Volume = length x width x height
• In this case the units would be cubic centimeters (cm3).
• So a box 2 cm x 3 cm x 5cm would have a volume of 30 cm3
V = L x W x H
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Base Unit for Volume
• The base unit for volume is the Liter.
• We measure volume with a graduated cylinder.
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Graduated Cylinders
• Liquids form curved, upper surfaces when poured into graduated cylinders
• To correctly read the volume, read the bottom of the curve called the meniscus
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Water Displacement to find volume • We can use water
displacement to find the volume of objects that are not boxed shaped.
• We can put water in a graduated cylinder. If a rock causes the level to rise from 7 to 9 ml, the the rock must have a volume of 2-mL.
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Metric Conversions
°F to °C Deduct 32, then multiply by 5, then divide by 9
°C to °F Multiply by 9, then divide by 5, then add 32
°C °F Description
100 212 Water boils
40 104 Hot Bath
37 98.6 Body temperature
30 86 Beach weather
21 70 Room temperature
10 50 Cool Day
0 32 Freezing point of water
-18 0 Very Cold Day
-40 -40 Extremely Cold Day (and
the same number!)
Celsius to Fahrenheit:
°C × 1.8 + 32 = °F
Fahrenheit to Celsius:
(°F - 32) / 1.8 = °C
Graphing
• Visual representations of numerical data.
• Help to see patterns and trends
• A way to organize data ▫ Line Graphs –
change over time ▫ Bar Graphs -
compare different things in a related category
Line Graphs
• X axis – the Independent variable
• Y axis – the Dependent variable
Bar Graphs • Same thing…
X axis – Independent variable
Y axis – Dependent variable
The Compound Light Microscope
Orientation through the microscope
Microscopic measurement
• http://virtualurchin.stanford.edu/microscope.htm
High power
field diameter
low-power field diameter (um) x low power magnification = high power magnification
Calculating Total Magnification
Total magnification = ocular lens x objective lens
8 Characteristics of ALL Living Things:
1. Living things Reproduce
2. Living things Grow and Develop
3. Living things are made of Cells
4. Living things are based on a Genetic Code
5. Living things maintain homeostasis
6. Living things need Food to produce Energy
7. Living things Respond to their environment
8. Living things Evolve because of Adaptations
Levels of Organization