Transcript What is Biology? - Kentucky Department of Education

What is Biology?
• Biology = the study of life
Bio- = life
-logy = the study of
• Concepts, principles and theories
that allow people to understand
the natural world
• Biologist = person who studies life
• Essential Questions in Science
– What?
– Why?
– How?
What do Biologist Study?
– Interactions of life
• Living things do not exist in isolation
• Living things depend on other living
things as well as non-living things
– Interactions of the environment
• No species can exist in isolation from
the environment around them
– Ex. If you study rabbits, you would also
study the plants they eat and animals they
prey on them
– Problems and propose solutions
Science v. Pseudoscience
• Read the Scientific American
articles “Drawing the line between
science and pseudo-science”
• As you read, write notes over the
distinction between:
Science
Pseudo-science
Also, include examples of Science
and Pseudo-science from the
article.
Science or Pseudoscience
Observation v. Inference
• Observation – Direct method of
gathering information in an
orderly way
– Example – DATA
• Qualitative – descriptions of things
• Quantitative – number data
• Inference – Assumption based on
prior experience
– The process of combining what you
know with what you have learned to
make logical conclusions
What is an organism?
• An organism is anything that
possesses all the characteristics
of life
• Living things are organized
– Living things have structure
– All parts function together in an
orderly way
Characteristics of Life
• Organization (Cells) - Living things have structure
– All parts function together in an orderly way
• Reproduction – making more organisms of the same kind
• Growth and Development – living things change
during their life
• Adaptation/Regulation – responding to changes in the
organisms surroundings
• Exchange Gases – Move gases in or out of body
(ex. CO2, O2)
• Use Energy– Metabolism (release of energy from food)
• Excretion – eliminating waste materials produced by the
organism
• Movement – all living things move (internal and external)
Are viruses living things?
• Viruses are not living things.
• Viruses are complicated
assemblies of molecules,
including proteins, nucleic acids,
lipids, and carbohydrates.
• On their own they can do nothing
until they enter a living cell.
Without cells, viruses would not
be able to multiply.
• So how do viruses work?
Levels of Organization
Animation link
Atom
The atom is a basic unit of matter
that consists of a dense central
nucleus surrounded by a cloud of
negatively charged electrons.
Molecule
• A group of two or more atoms
held together by chemical bonds
Organelle
An organelle is a specialized subunit
within a cell that has a specific function,
and is usually separately enclosed within
its own lipid bilayer.
The name organelle comes from the idea
that these structures are to cells what an
organ is to the body.
Cell
• The cell is the basic structural and
functional unit of all known living
organisms.
• It is the smallest unit of life that is
classified as a living thing.
• Is often called the building block
of life
Tissue
• A group of biological cells that
perform a similar function
Organ
• A collection of tissues joined in a
structural unit to serve a common
function
Organ System
• a group of organs that work
together to perform a certain task.
Examples: circulatory system, the
respiratory system, the nervous
system, etc.
Organism
• Single individual
Population
• Group of
organisms of same
species that
interbreed and live
in the same place
at the same time
• Compete for
resources
Community
• Many interacting
populations
• Change in one
population causes
changes in the
others
Ecosystem
• Interacting
populations and
the abiotic factors
• Types: Terrestrial
Freshwater
Saltwater
Biosphere
• The portion of the
earth that supports
life
• How do we answer questions
about life?
– We use the Scientific Method
• Set of organized steps that help us
answer questions about observations
that we make
Steps of the Scientific Method
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Observation
Research
Hypothesis
Procedures
Experiment
Organize Data
Make Conclusion
Share Results
Observation
• Use your 5(4) senses to notice
things around you
– See an organism change color
– Hear an organism make a sound
– Feel the texture on an organism
– Smell an odor
– Taste – Never taste anything in lab!!!
• Develop a question based on your
observations
Research
• Find out as much as you can
about what you observed
– Look it up!
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Computer
Books
Journals
Talk to experts in the field
Newspaper
TV
Prior knowledge
Hypothesis
• Make an educated guess
– I stress the word “educated”
• Your hypothesis is a guess, but it is a
guess based on information that you
have learned from your research
• I hypothesize that…..
Procedures
• Write the steps you will use to test
your hypothesis
– First I will ….
– Then I will ….
– After that, …..
– Next, ….
– Finally, ….
Experiment
• Test your hypothesis using the
procedures you have written\
– When you experiment
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Follow procedures closely
Follow safety rules
Make observations
Record data collected
Organize Data
• Try to make sense out of the data
you collected and organize it in a
way that tells a story
– Make charts, graphs or tables
– Look for “trends” in your data
Make a Conclusion
• Determine what your data is
telling you.
• Does your data help to confirm or
disprove your hypothesis?
• Does your data answer your initial
question?
• What does it mean?
Share Your Results
• If you don’t share what you found
how will anyone know?
• It is important for scientist to let
others know what they have
discovered.
• Scientist usually publish their
research in scientific journals
– When scientist publish their research they
use a specific format. All scientific
journals use the same format
What are you doing Friday Night?
• Use the Scientific Method to go
through the steps you would use to
figure out what you will do this Friday
night.
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Observation – what is there to do???
Research – find out!
Hypothesis – what do you think will happen?
Procedures – how will you go about it?
Experiment – the actual activity
Organize Data – What happened
Make Conclusion – Ok, so how did it go?
Share Results – You know you will tell all your
friends about it…
Experimental Variables
• When you do an experiment you
should always be aware of your
variables
• There are three types
– Independent Variables
– Dependent Variables
– Controlled Variables
Independent Variables
• The condition in the experiment
that is changed
– By changing the independent
variable, a scientist can observe or
measure the effects of the change
Ex. Growing plants
You want to determine the effect of
water on the growth of a plant, in
that case, your independent variable
would be water.
Dependent Variables
• Any change that results from the
manipulation of the independent
variable
• It’s the thing you measure or collect
data on
Ex. Growing plants
When you change the amount of water
that you give the plants (independent
variable), the growth of the plant slows
down. The dependent variable is the
height of the plant or the number of
flowers that the plant produces
Controlled Variables
• Also referred to as a “Constant”
• The standard, the parts of the
experiment that are kept the same.
Ex. Growing plants
You change the amount of water you
give the plants (independent variable),
but you keep everything else the same,
like amount and type of soil, and
fertilizer, amount of sunlight,
temperature….
Experimental Design
• Experimental Group
– The group that receives the change
• Control Group
– The group that remains the same.
The original condition
Replication in Experiments
• You can’t determine the effect of
less water on a plant if you have
only one plant.
• You must replicate
• More is always better!
What happens when many people
come up with the same results?
• Theory
– After a hypothesis has been tested
and the same results are obtained
many times by many people, a
hypothesis may become a theory.
• Law
– After a theory has been tested and
the same results are obtained many,
many, many times by many, many,
many people, a theory may become a
law.