Transcript Ch 1 - Wando High School

Chapter 1: Introduction to Biology--Measurement, Graphing, and Scientific
Method
Types of Research
• Two main types
– Quantitative
• Results are numerical data
– Descriptive
• Relies on observations of situations out of scientist’s
control
• Results are descriptions of observations
Quantitative Research
• Data are analyzed by comparing the numerical
values
– Tables
– Graphs
• Measurements are made using the International
System of Measurement (SI)
– Based upon the metric system
– Understandable to scientists around the world
Tables
• All tables must include
the following
– Title
– Clearly labeled columns
and rows
– Labeled units
• Data should show
relationship between
independent and
dependent variable
Effects of Fertilizer on Plant Height
Amount of Plant
Fertilizer (g)
Independent
Height of
Plant (cm)
Dependent
2
12
6
20
10
4
Graphs
–
–
–
–
–
Title
A label for each axis
Labeled units
Legend
Data properly depicted
* Independent on x-axis
* Dependant on y-axis
y-axis
• All graphs must include the following
x-axis
Graphs
• What type of graph should I use?
• Line
– For continuous quantitative data
• Height of plant over time
• Stock market prices over time
– Line graph relationships
• Direct variation – one variable
increases as the other increases
(or decreases as the other
decreases)
• Inverse variation – one variable
decreases as the other
increases
Graphs
Favorite TV Show
• Bar
30
– For non-continuous data
(usually in categories)
• Number of people who
watch each TV show
surveyed
# of People
25
20
15
10
5
0
CSI
Tyra
Lost
Survivor
TV Shows
Percent of People Chose Each Show as
Their Favorite
• Pie
– For data that are parts of
a whole
25%
25%
CSI
Tyra
Lost
• Percentage of those polled
that chose each TV show
Survivor
30%
20%
International System of Measurement (SI)
• Basic units of measurement
– Length – meter (m)
• Tool – ruler or meter stick
– Volume – liter (L)
• Tool – graduated cylinder
– Mass – gram (g)
• Tool – balance
– Time – second (s)
• Tool - stopwatch
– Temperature – Kelvin (K) [We will most often use Celsius (°C)]
• Tool - thermometer
Units of Measurement
• Metric system – based on 10
kilo (k) –
kilometers (km) 1000 meters
hecto (h) –
hectometers (hm) 100 meters
deca (da) – decameters (dam) 10 meters
Basic unit (m, L, g) –
meter (m)
1 meter
deci (d) –
decimeter (dm) 0.1 meter
centi (c) –
centimeter (cm) 0.01 meter
milli (m) –
millimeter (mm) 0.001 meter
Converting one metric unit to another
k
h
da
Basic unit
(m, L, g)
d
c
m
• To convert from one unit to another, move the decimal
same direction and number of places the units are
from each other
– 12 kilometers is ?? centimeters
• centimeters are 5 places to the right
• 1,200,000 cm
– 134 decigrams is ?? hectograms
• hectograms are 3 places to the left
• 0.134 hg
Science and Society
• Ethics – moral principles and values held by
humans
– What role do ethics play in scientific research and
results?
• Can science answer all questions?
• Technology – application of scientific
research to address society’s needs
– Can technology solve all problems?
Scientific Investigation vs Technological
Design
• Scientific Investigation – process followed to
determine the relationship between the independent
and dependent variable described by the hypothesis
– Goal is to answer a question, perhaps advance the
knowledge of science
• Did using this new fuel help lower pollution?
• Technological Design – process followed to design
products or processes to meet specific needs
– Goal is to create a specific outcome, perhaps advance the
standard of living in societies
• We have created a lower pollution emitting car
Scientific Investigation vs Technological
Design
Scientific Investigation
Technological Design
Identifies a problem – asks a question
Identifies a problem or need
Researches related information
Researches related information
Designs an investigation or experiment
Designs a process or a product
Conducts the investigation or
experiment – repeated trials
Implements the design or the process –
repeated testing
Analyzes the results
Analyzes the results
Evaluates the conclusion – did the
results refute or verify the hypothesis
Evaluates the process or product – did
it meet the criteria
Communicates the findings
Communicates the product or process
Methods of Biology
• The series of steps used by scientists to gather
information and answer questions is called the
Scientific Method.
• If you had a question or a problem to solve,
what steps would you go through to resolve it?
7 Steps of the Scientific Method
• Number 1 - State the Problem
– Take note of something no one has seen before or
has yet to explain
7 Steps of the Scientific Method
• Number 2 - Gather Information
– Observation - Gathering information using your senses
– Information gathered should be:
• Credible - trustworthy
• Accurate - correct – based on supported data
• Relevant - applicable, related to the topic of the investigation
– These sources could be
•
•
•
•
Previous scientific investigations
Science journals
Textbooks
Other credible sources, such as scientifically reliable internet sites.
Observation vs. Inference
• Inference – making a judgment based upon an
observation and past experience
• Make at least 3
observations
about this picture.
• Make at least 3
inferences about
this picture.
• Make three
observations and
inferences with this
new information
• Does the new
information change
your responses?
What does this final picture do to your previous
inferences?
What does this picture do to your previous
inferences?
7 Steps of the Scientific Method
• Number 3 - Form a Hypothesis
– Create a testable explanation for the situation that
you observed
7 Steps of the Scientific Method
• Number 4 - Test the Hypothesis - Experiment
– Design an experiment
• An organized procedure for collecting information under
controlled conditions
– The experiment will have two groups
• Control – all conditions
are kept the same
• Experimental – conditions
match that of the control
except for the one factor
being tested
7 Steps of the Scientific Method
• Testing…
• An important part in the experiment design is the
sample size – the number of test subjects
– A large sample size increases the reliability of results
– A large sample size decreases the effect of errors on the
outcome
• How could having a larger sample size help the
following experiments?
– Tim tested the effect of fertilizer on two plants.
The one with fertilizer grew taller than the
one without it.
– Suzy developed a drug to lower cholesterol.
She gave it to two patients who later died.
7 Steps of the Scientific Method
• Testing…
– The condition that is changed in the experiment is
the independent variable – it will be the only thing
that can affect the outcome
– The outcome observed is the dependent variable –
it depends upon the changes made to the
independent variable
– Note: Some experiments cannot be controlled so
other observation methods have to be used
• Example: wildlife study
Independent vs. Dependent Variables
• Mark the dependent and independent variable in
each situation
• Suzy wanted to test how changing her diet affected her
weight.
• The track team members that ran extra laps at practice
ran better times at the next meet.
• Jack planted half of his roses in the shade and the other
half in the direct sunlight and measured the differences
in plant height and bloom production.
7 Steps of the Scientific Method
• Number 5 - Record and Analyze Data
– Record Data
• Data – information obtained from experiments
– Observations
– Results
• Data should be precise and accurate
– Precision – the degree to which measurements made in the same way
agree with each other
» If you and I measure it, do we get the same thing?
– Accuracy – the degree to which the value measured agrees with the
true or accepted value
» Even if we both got the same thing, did we measure it correctly?
– Data must then be analyzed or interpreted
• Graphs
• Tables
• Charts
7 Steps of the Scientific Method
• Number 6 - State a Conclusion
– Did the data support the hypothesis?
• If yes…
– Verify results
» Can the experiment be repeated?
» Do other scientists support the findings?
• If no…
– Repeat the experiment
– Revise the experiment
– Develop a new hypothesis
7 Steps of the Scientific Method
• Number 7 - Repeat
– No matter what happened!
– Fact – Observable phenomenon that can be
confirmed by scientists many times
– Form a Theory – a hypothesis tested over a long
period of time, supported by separate experiments
Fact vs. Theory
• Which is Fact…Which is Theory?
– Dinosaurs were cold blooded.
– The caterpillar is 3.5 cm long.
Using the Scientific Method
• You haven’t been catching as many fish as
you used to at your best fishing spot
• Your friend tells you that you and your brother
smell funny
Identifying Study Components
A student noticed that when a dog is cut, the dog periodically licks its wounds. Usually after a few
days, the wound begins to heal without ever showing signs of infection. The following steps
outline the student's line of reasoning:
A. I wonder why the dog's wound doesn't become infected.
B. The dog's saliva must prevent the growth of infection-causing bacteria.
C. I'll obtain a bacterial culture and grow the same kind of bacteria in two identical culture dishes.
Once the bacteria start growing, I'll add dog saliva to only one of the dishes and leave the other
alone. I'll cover both dishes. Then I'll observe what happens each day for a week.
D. Even after adding the dog saliva to one of the dishes, the bacteria continued to grow in both
dishes over the course of the week. However, the bacteria in the treated dish grew more slowly
than the bacteria in the untreated dish.
E. I think I'll try something else. I'll start with two identical culture dishes, as before, and use the
same kind of bacteria in each dish, but this time I'll treat one dish with dog saliva before I add the
bacteria. I'll observe what happens each day for a week.
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What was the student’s hypothesis?
Which step described the experimental set up?
Identify the control
What is the independent variable?
What is the dependent variable?
What data did the student collect?
What is a possible conclusion from this experiment?
Is that conclusion a fact or an inference?
Identifying Study Components
A student noticed that when a dog is cut, the dog periodically licks its wounds. Usually after a few
days, the wound begins to heal without ever showing signs of infection. The following steps
outline the student's line of reasoning:
A. I wonder why the dog's wound doesn't become infected.
B. The dog's saliva must prevent the growth of infection-causing bacteria.
C. I'll obtain a bacterial culture and grow the same kind of bacteria in two identical culture dishes.
Once the bacteria start growing, I'll add dog saliva to only one of the dishes and leave the other
alone. I'll cover both dishes. Then I'll observe what happens each day for a week.
D. Even after adding the dog saliva to one of the dishes, the bacteria continued to grow in both
dishes over the course of the week. However, the bacteria in the treated dish grew more slowly
than the bacteria in the untreated dish.
E. I think I'll try something else. I'll start with two identical culture dishes, as before, and use the
same kind of bacteria in each dish, but this time I'll treat one dish with dog saliva before I add the
bacteria. I'll observe what happens each day for a week.
•
•
•
•
•
•
•
•
What was the student’s hypothesis?
Which step described the experimental set up?
Identify the control
What is the independent variable?
What is the dependent variable?
What data did the student collect?
What is a possible conclusion from this experiment?
Is that conclusion a fact or an inference?
• What is Biology?
– The study of life
• What kind of things would a Biologist
study?
– Characteristics of known and new living
things
– Interactions between living things
– Interactions between living things and the
environment
– Problems living things face and possible
solutions
Organisms possess all characteristics of
life. Which of these is not alive?
http://en.wikipedia.org/wiki/Bacteria
5 Characteristics of Living Things
• #1 Living things are Organized
– the parts that make up the organism are arranged in
an orderly structure
– Levels of Organization
Atoms
Molecules
Organelles
Cells
Tissues
Organs
System
Organism
Population
Communities
Ecosystems
Characteristics of Living Things: #2
• Living things Reproduce
– organisms produce offspring (reproduction) for the
survival of the species
– species: group of organisms
that can interbreed and
produce fertile offspring
in the future
Characteristics of Living Things : #3
• Living things Change during their lives
– Growth: increase in the amount of living material
and the formation of new structures
– Start as single cells and become more complex
– Changes throughout life are known as development
Characteristics of Living Things : #4
• Living things Respond to their surroundings
– Organisms are affected by their environment (such as air,
water, weather, temperature, other organisms)
– Conditions in the environment can cause a reaction by the
organism. Stimulus  Response
– Why respond?
• To Survive!
– Regulating internal conditions
suitable for survival: homeostasis
• Water, temperature, nutrients
Characteristics of Living Things: #4 cont.
• Response…
– Responding to surroundings requires Energy!
– Energy – ability to do work
• From food
Characteristics of Living Things: #5
• Living things Adapt and Evolve
• Organisms develop structures, behaviors, and internal
processes to help them respond to their environment –
adaptations
• The gradual accumulation of these adaptations is
evolution
5 Characteristics of Living Things
• What kind of adaptations have these organisms
developed?
http://www.saburchill.com/questions/lanlt00
1.html
•Where do they live?
•What do they eat?
•How do they hunt for their
food?
•How might they avoid
predators?
•In what other ways might they
have adapted themselves or
their senses for survival?
Manatee
Whooping Crane
•Where do they live?
•What do they eat?
•How do they hunt for their
food?
•How might they avoid
predators?
•In what other ways might they
have adapted themselves or
their senses for survival?
Blue Poison Dart Frog
•Where do they live?
•What do they eat?
•How do they hunt for their
food?
•How might they avoid
predators?
•In what other ways might they
have adapted themselves or
their senses for survival?
Manatee
• West Indian manatees are large,
gray aquatic mammals with bodies
that taper to a flat, paddle-shaped
tail. They have two forelimbs,
called flippers, with three to four
nails. The manatee's closest land
relatives are the elephant. Manatees
can be found in shallow, slowmoving rivers, estuaries, saltwater
bays, canals and coastal areas.
Manatees are a migratory species.
Manatees are gentle and slowmoving. Most of their time is spent
eating, resting, and in travel.
Manatees are completely
herbivorous. They eat aquatic
plants.
Whooping Crane
• The Whooping Crane is the tallest
flying North American bird. The
Whooping Crane is native to a
diverse array of ecosystems. Lives
in the coastal marshes of Louisiana
and Wetland Ecosystems. All
cranes are omnivorous. Principal
foods of the Whooping Crane on
their breeding grounds are
mollusks and crustaceans, insects,
minnows, frogs, and snakes.
Habitat loss and alteration is one of
the greatest threats.
Poison Dart Frog
• These little frogs are easily recognized by their blue color, which is generally
darker on the limbs and belly and overlaid with black spots or patches,
especially on the head and back. As their name implies, poison dart frogs can
release toxins from the skin that are distasteful and potentially lethal to
would-be predators. Three very toxic species of poison dart frogs from
Colombia and South America are utilized by Indians to poison the tips of
blowgun darts. Blue poison dart frogs are active during the day and can be
found hiding among boulders and debris near streams; however, they lack toe
webbing and are poor swimmers, so they are never found in the water.
• A constant forager, this frog is always searching for ants, termites, tiny
beetles, and any other small insect it may find among the leaf litter.
• These frogs are found in a few isolated “rain forest islands” in South America.
• Other than certain snakes and large spiders, there are few predators that can
cope with the noxious poisons of adult frogs.