What Makes Science so Hard?
It’s the ridiculous vocabulary!!!!
What do you think these words mean?
Auscultation
Borborygmus
Cacodyl
Emesis
Eructation
Flatus
Mastication
Micturation
Osculation
Oscitancy
Stertor
Wamble
Prefixes & Suffixes
• If you learn certain prefixes and suffixes,
you can figure out certain words. Don’t let
the vocabulary in science bog you down!!
You can figure it out.
Watch this video and describe
what it may have to do with
Biology.
• http://video.search.yahoo.com/search/video;_ylt=
AiLXpPTFzpxzCqWvSZXCemKbvZx4?p=giraffe
s+fighting&toggle=1&cop=mss&ei=UTF8&fr=yfp-t-701
• http://video.search.yahoo.com/search/video;_ylt=
AiLXpPTFzpxzCqWvSZXCemKbvZx4?p=giraffe
s+fighting&toggle=1&cop=mss&ei=UTF8&fr=yfp-t-701
Watch this video and describe
what it has to do with Biology.
• http://www.youtube.com/watch?v=btuxOC2IzE
• http://www.youtube.com/watch?v=md2CW
4qp9e8
Life Science
Biology – The study of living things
Branches of Biology
1.
2.
3.
4.
Ecology – The study of the environment
Zoology – The study of animals
Doctor – Human anatomy
Botany – The study of plants
Careers in Biology
Global Ecology
Marine Biologist
Herbatologist
Infectious disease
DNA and molecular Biology
Paleontologist
Doctor
Earth Science
Earth Science(Geology)– The study of the Earth
Branches of Earth Science
1.
2.
3.
4.
5.
Oceanography – Study of the Ocean
Volcanology – Study of volcanoes
Seismology – Study of earthquakes
Meteorology – Study of the weather
Astronomy – Study of space
Physical Science
Physical Science – Study of both matter and energy
Branches of Physical Science
1.
2.
3.
4.
Chemistry – The study of all forms of matter
Physics – The study of energy
Astronomy – Movement of objects in space
Oceanography – Study of the waves and tides
What is science?
How do scientists work?
What is Science?
Science is an organized way of gathering
and analyzing evidence about the natural
world. It’s asking questions!
I want to teach you this year about the world around.
Everyday,I want you to leave here with new knowledge
of the world around you !!!!
Science Methodology
Scientists go about solving problems in a
certain way. The methodology is always the
same. It is called Scientific Method!
STEP 1 - Good Observations
Being a good scientists involves making
great observations and then asking
questions. Several people can observe
the same event but have different
explanations. This happens in crime
scenes all the time.
Describe what you observe in this picture. DO NOT discuss it
with your neighbors.
Observations Leads to Data
Collection
• Data collection leads to forming an
hypothesis.
• Two Types of Data
1. Quantative
2. Qualiative
There is two types of data researchers can collect:
1. Qualitative data: factual description that do not
use numbers. For example, describing the
behavior of animals, color of eyes, how
mothers react to their young, etc.
2. Quantitative data: factual information that
uses number. For example, counting the
number of young, measure how tall something
grow, etc.
Qualitative or Quantitative?
Parts of a Controlled Experiment
•Constants – all the things you keep the
same(same # of plants in a container,
same amt of sunlight, same amt of dirt,
same amt of fertilizer)
*Control Group: The experiment group without
the variable being tested.
Qualitative or Quantitative?
Observations vs. Inferences
An OBSERVATION the act of noticing and describing
events or processes. You do it with your eyes; when we
see something, we observe it. However, all five of our
senses can be used to make observations: sight, hearing,
taste, touch, and smell.
An INFERENCE is an assumption or conclusion based on an
observation. It is a logical interpretation based on
observations and prior knowledge.
Observation Vs. Inferences
• When collecting data, as a scientists you
must only record your observations and not
read anything into what you see. Your
inferences are in the conclusion.
Name 2 observations and 2
inferences
Name 2 observations and 2
inferences
The Scientific Method
The scientific method is a process for experimentation
that is used to explore observations and answer
questions. Scientists use the scientific method to
search for cause and effect relationships in nature.
In other words, they design an experiment so that
changes to one item cause something else to change
in a predictable way.
THE SCIENTIFIC METHOD – a step by
step way scientists solve problems.
STEP 1: Problem Statement – always written in
questions form
The scientist then raises a question about what (s)he sees
going on!!!
Question: How many licks does it take to get to the center of
Tootsie roll pop?
Research
Step 2: Research – background information about
the topic. You have to know what you about you
topic before you can experiment.
Could be notes, books, internet resources, asking an
expert, etc.
Step 3: Hypothesis – a possible answer to the
problem statement.
Always written as an IF > THEN statement.
If I give 2 cups of water to a tomato plant, then it
will grow better than plants given more or less water.
This is a tentative answer to the question: a testable
explanation for what was observed. IT IS NOT ALWAYS
CORRECT!
Write a hypothesis for the picture below.
Controlled Experiment
•Experiment is used to compare an experimental
group with a control group to answer a problem
•Not all experiments are controlled. You can
conduct an experiment without variables. Why is
the car not running? You are just solving a problem!
* Contains dependent and independent variables.
Example – king snake vs. coral snake
Procedure – Controlled Experiment
Step 4: Procedure – a numbered step set of directions
that explains the experimental setup. Includes materials
list.
Variable – what is being tested, what is different in
the experiment (the amount of water given to the plants)
Types of Variable in a Controlled
Experiment
•Independent Variable – The independent
variable is the variable that is manipulated by
the researcher.
*Dependent variable – factors affected by the
independent variable.
What is the Dependent and Independent
Variable?
Data and Analysis
Step 5: Data and Analysis – explanation of what
happened in the experiment. All data collected should
be displayed on a data table or on a graph.
DATA:factual information gatehred in the
experiment.(information or numbers from experiment)
What is some data you could collect from these pics?
Observations Leads to Data
Collection
• Data collection leads to forming an
hypothesis.
• Two Types of Data
1. Quantative
2. Qualiative
There is two types of data researchers can collect:
1. Qualitative data: factual description that do not
use numbers. For example, describing the
behavior of animals, color of eyes, how
mothers react to their young, etc.
2. Quantitative data: factual information that
uses number. For example, counting the
number of young, measure how tall something
grow, etc.
Qualitative or Quantitative?
Parts of a Controlled Experiment
•Constants – all the things you keep the
same(same # of plants in a container,
same amt of sunlight, same amt of dirt,
same amt of fertilizer)
*Control Group: The experiment group without
the variable being tested.
Qualitative or Quantitative?
Step 6: Conclusion – the answer to the problem
statement based on the data you collected.
Was the hypothesis correct or not and identify
any errors that might have occurred in the experiment.
Data and conclusion
• Over the next month, you would collect
data(height).
• Conclusion: at the end of month, see which
group grew the best.
Scientific Method
•
1. Name the steps of the scientific method
2.Explain how to write a hypothesis.
3.Contrast a constant and a control group.
4. Define a variable.
5.Explain why it is important to have a control
group
6. Explain how to write a procedure.
spontaneous generation
Redi, Needham, Spallanzani, and Pasteur
Spontaneous Generation
• For much of history, people believed that animals could come
from non-living sources. They thought:
– Frogs developed from falling drops of rain
– mice arose from sweaty underwear
– and flies arose from decaying meat.
• This is called abiogenesis
• Also known as spontaneous generation
• These ideas
were followed
because people
simply
accepted what
they were told
The Power of Authority
• In the past, people
believed what they were
told by “authorities” such
as the Church, or the
ancient Greek philosopher
Aristotle
• Questioning Aristotle was
like questioning the
Church....
• One “scientist” put forward the belief that mice could
be generated spontaneously from wheat and a sweaty
shirt.
• The wheat provided the “nutritive power” and the
shirt provided the “active principle.”
• “active principle” = a mysterious “life-force” that
allowed spontaneous generation to occur.
Francesco Redi - 1668
Italian Physician challenged abiogenesis
Hypothesis: If there are maggots present, then
they did NOT come from rotting meat.
Variables: Open meat vs. not open meat
Conclusion: Only maggots on the open meat
so maggots came from flies.
“The flesh of dead animals cannot engender
worms unless the eggs of the living being
deposited therein”
REDI’S EXPERIMENTS!!
• Put dead snakes, eels, and veal in large wide
mouthed vessels. Sealed one set with wax
and left the other set open to air.
• Decaying meat was teeming with maggots,
sealed meat had no maggots
• Wax sealed vessels failed to produce maggots
because flies were unable to reach the meat
1668 -- Francisco Redi (Italian physician & poet)-attempted to disprove the theory of Spontaneous Generation.
Redi’s critics said:
• You have too many variables
• There is a lack of access and
a lack of air.
• We ALL know that everything
needs air.
• Of course no flies grew!
• You haven’t proven
anything.
Redi’s Second Experiment
• They argued that the flies were coming
from the air.
• He added a third set of jars that had mesh.
• This proved that the flies came from
maggots.
Redi part 2 – answer to critics
fine mesh allows in air,
but not flies
flies laid eggs on top of mesh
no maggots in meat
Redi’s Conclusions:
• “All living beings come from seeds of the
plants or animals themselves”
• However, if someone were to demonstrate
even one exception to this hypothesis, then
Redi’s hypothesis would be rejected.
John Needham - 1745
• He believed in abiogenesis(SG).
• Hypothesis: If you boiled broth, living
organisms still grow from nonliving broth.
• Experiment: He boiled broth and bacteria
still grew a few days later.
John Needham (English Clergyman)
wondered if this would work with micro
organisms in1745
• Everyone knew that boiling killed organisms.
• Needham prepared various broths and showed
that they contained microbes. He had a
microscope!
• Then he boiled them, and showed that there
were no longer any microbes.
• He ensured the stoppers were loose, so that air
would not be excluded
• Then, after a few days, microbes had
reappeared!
• This was “proof” that the microbes had
spontaneously generated from the non-living
broth.
• BUT: how was this evidence of
Needham’s error
a faulty experiment?
– what ERROR in experimental
method is shown here?
• Hypothesis: microbes MUST
HAVE arisen spontaneously from
the broth.
• Conclusion: there is no other
place the microbes could come
from (other than the broth).
• error: microbes could have come
from the air!
Lazzaro Spallanzani - 1745
• Italian priest and biologist
• Hypothesis: If you boiled the broth hotter,
then there would not be any bacteria.
• Experiment: He boiled the broth, sealed
them. Then boiled again to make sure killed
the bacteria.
• Conclusion: No spontaneous generation.
Spallanzani’s (Italian Naturalist)
-- 1745
Disagreed with Needham
•
• Claimed he didn’t seal jars well enough
• He said microbes could have come from the air
• He repeated Needham’s experiment, but changed two things:
– boiled flasks longer, and
– SEALED THEM after boiling by fusing the glass tops shut
– (hermetically sealed – absolutely airtight)
• Result: NO growth in ANY flask
Needham criticizes Spallanzani’s first experiment
• BUT Needham said: you boiled it
TOO LONG, and:
• You spoiled the vegetative power
by boiling.
• You killed the ability of the broth
to give life.
• Life can still come from broth -but the broth must not be
“damaged” by boiling.
Spallanzani’s secondtight
experiment
seal loose seal
• he did TIMED
BOILINGS
• then left them partially
sealed
• some partially sealed,
some hermetically
sealed as in his
previous experiment
• hypothesized that
more boiling should
lead to less life
• he left some jars as
Needham had (leaky
seals), to ensure
“active principle” was
not damaged
30 mins
60 mins
90 mins
120 mins
Spallanzani’s second experiment -results tight seal loose seal
• this showed
TWO main
things:
• boiling did NOT
damage broth’s
ability to support
life
• Conclusion:
growth depended
on the SEAL
only
30 mins
60 mins
90 mins
120 mins
Louis Pasteur
(French chemist) entered a contest sponsored
1859–by French Academy of Sciences to prove or
disprove Spontaneous generation.
• used swan-necked flask
• flask allowed in air, but
trapped dust (and
microbes)
• boiled infusion
• showed that NO growth
occurred, even after many
days
• BUT -- what about
damaging the “active
principle”?
• Pasteur showed
that the active
principle was NOT
damaged
• at any later time,
he could tip the
flask
• this allowed
nutrient broth to
contact the dust
• this carried
microbes into the
broth
• result: growth!
area where
dust had
been trapped
Pasteur squashes the idea of abiogenesis completely!
• Since then, no one has been able to refute Pasteur’s experiment
• scientists everywhere soon came to accept that abiogenesis did
NOT EXIST.
• but: then how did life on this planet start in the first place?
Louis Pasteur - 1845
• French Chemist – FINALLY Solved NO
abiogenesis!
• Hypothesis: If the broth is exposed to air
with dust, then there will be more bacteria.
• Experiment: Exposed broth to different
amounts of dust.
• Conclusion: More dust ; more bacteria