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The goal of science is to investigate and understand the ______________, to explain events in the natural world, and to use those explanations to make ___________________
To simplify, science is
natural world
useful predications
an organized way of using evidence to learn about the natural world
Science can also just refer to theknowledge scientists have complied
Scientific thinking usually starts with ________________an observation
An observation is just gathering info in an orderly way
_______= the information gathered through observations
There are 2 main types of data:
Data
qualitative and quantitative
Qualitative =____________________—written descriptions of what scientists observe.
Quantitative = results from experiments that use __________________________— numerical data can be used to make graphs, tables, or charts.counts or measurements
observational data
So we have made our observation, now what?
Scientists come up with a ______________ – a proposed explanation for a set of observations
Hypothesis’ must be able to be tested – some through ________________________ and some through further collection of data
hypothesis
controlled experiments
new medical treatments, new sources of fuel, different uses for waste
Biology can be considered a way of knowing – it is an ongoing process because things continue to change (we don’t leave things alone!!!)
Biological research can lead to all sorts of different things;
Can science answer all questions? some questions just don’t seem to apply to
science: good vs. evil
Good scientists are __________– they question both existing and new hypothesis they always want to know more
skeptics
Observations lead to questions – we need a way to test those questions. That’s where an experiment comes in.
The basic steps in designing an experiment:
1. Ask the question
5. Draw a conclusion
2. Form a hypothesis from the question3. Set up a controlled experiment
4. Record and analyze results
Aristotle came up with the idea that living things could come from nonliving things – he said there were special “vital” forces that brought this about – this became known as
To help understand each step, let’s look at some well-known experiments from history
This idea persisted for a while – it was only challenged some 400 years agospontaneous generation
These ideas were questioned because of simple observations: maggots on meat, mice on grain, beetles in poo
Redi, an Italian physician, came up with a different hypothesis as to why maggots appear on meat __________ His idea was that flies laid tiny eggs that produced the maggots
(step 1)
(step 2)
Controlled experiment = an experiment in which only _______________ is changed at a time all others are kept unchanged
Redi came up with a controlled experiment(step 3)
one variable
(controlled)
The variable being tested is the
The variable that changes in response to being manipulated is the
Redi predicted that keeping flies away from meat would prevent maggots, so the variable he changed was the flies access to the meat
independent variable
dependent variable
He set up meat in 2 sets of jars – most factors were the same: the jar, type of meat, location, temp, time – the only thing that changed was
the gauze over the jar
Redi recorded his data in notebooks for future generations of scientists
Redi’s finding ___________ his hypothesis – if the flies couldn’t get to the meat, there were no maggots
(step 4)
(step 5)
supported
Experiments are often repeated to make sure that results are
A key assumption in science is that experimental results can bereproduced
valid
Sometimes it’s not always possible to do an experiment to test a hypothesis
_______________ are used as a way to make observations and gather further information to help support a hypothesis
Field studies
When there is enough evidence from several investigations and a hypothesis is very well supported it is considered
Some people might try to criticize something because it is “just a theory”, but in science, a theory is
a theory
a well tested explanation that unifies a broad range of observations
We ask questions all the time; how, what, when, where, why?This is exactly what biologists do – they ask questions about living things
Biology is just the study of life
Bio =Logy =
lifethe study of
So how do we classify living things; what characteristics do they have?
All living things (___________) share the following characteristics, they are:
organisms
_______ = a collection of living matter enclosed by a _____________ that separates the cell from its surroundings
1. Are made up of units called cells
Cellbarrier
_____________________ = cells from 2 parents unite to produce the first cell of the new organism
______________________= the new organism has a single parent it divides in half to form 2 new organisms
2. Reproduce
Sexual reproduction
Asexual reproduction
Organisms inherit traits from their parents through
This code determines the inherited traits of every organism on Earth
3. Based on a universal genetic code
DNA – the genetic code
For some single-celled organisms, _________ is just an increase in size
All of the changes that take place during the life of an organism =
4. Grow and develop
growth
development
Organisms need material and energy just to stay alive!
_____________= the combo of chemical reactions through which an organism builds up or breaks down materials during life processes
5. Obtain and use materials and energy
Metabolism
_________= a signal to which an organism responds
Organisms can react to both _____________________ stimuli
6. Respond to their environment
Stimulus
internal and external
_______________ = the process by which organisms keep internal conditions constant for survival
Organisms go to great lengths to maintain conditions (temp and water content)
7. Maintain a stable internal environment
Homeostasis
It can take _________________________ of years for these changes to really be apparent
Ex. Desert plants have evolved and adapted to living in very hot, dry climates
8. As a group, change over time
hundreds or thousands
Since there is a very large range of living things, there are many branches of Biology
Some of the levels that biology can study are…
BiospheresMolecules
Cells
Groups of cells
Organisms
PopulationsCommunities
Ecosystems
Scientists use all sorts of tools to help make observations and _____________________
We need a _________________ _________________ so that scientists all over the world can understand it
take measurements
common systemof measurement
The ________________ is a decimal system of measurement whose units are based on certain physical standards and are scaled on multiples of
A revised version of the metric system is the
metric system
10
International System of Measurement (SI)
Measurement
Unit Symbol
Length meter m
Mass kilogram kg
Time second s
Temperature Kelvin K
Amount of substance
mole mol
_______________= devices that produce magnified images of structures that
are too small to see with the naked eye
Microscopes
Compound light microscopes use ______ lenses to form an image
They can magnify an object by about
____________________ produce an image by focusing visible light raysLight microscopes
two
1000 times
______________________ produce an image by focusing beams of electronsImages can get 1000 times more detailed than that of a light microscope
There are 2 main types of electron microscopes:
Electron microscopes
transmission electron (TEM) and scanning electron (SEM)
TEMs shine a beam through a thin specimen –
SEMs scan the beam across the surface of the specimen –
used to view details in the specimen
can create 3D images of the surface of the specimen