Transcript The Nature of Biology_020614

The Nature of Biology
Module 1: How to Define Life
How do you design an experiment?
A. Problem/Purpose
1. The question the lab will answer
2. Identifies the independent and dependent variables
a. Independent variable – the factor the scientist changes from
group to group
b. Dependent variable – the factor the scientist measures to
see the effect of the independent variable
Variables and Controls Videoclip
How do you design an experiment?
B. Research/Background
Information
1.
2.
Lets the reader learn about the topic
Helps the scientist develop an
educated hypothesis
C. Hypothesis
1.
2.
An educated prediction
Can be tested, proven false, and
agrees with previous research
How do you design an experiment?
•
D. Procedure/Experiment
1. Steps must be precise and detailed
2. Has one control group
a. Normal conditions or absence of independent variable
b. Used for comparison
3. Experimental group(s) have only one changing
variable (which is the independent variable)
How do you design an experiment?
– E. Observations/Data
1. Must be objective.
a. Good Example: The bacterial colony is yellow.
b. Bad Example: The bacterial colony is nasty.
2. Use measurements whenever possible.
a. Good Example: There are 50 bacterial colonies.
b. Bad Example: There are a whole bunch of colonies.
How do you design an experiment?
E. Observations/Data
4. Do not draw conclusions in the data section of the
report.
a. Good Example: There are bacteria and fungal colonies in the
shoe section.
b. Bad Example: The shoe was really dirty and so it was the
most contaminated and grew a lot of stuff.
5. Should be organized.
a. May use a graph, table, or drawing(s).
b. Always include units of measurement and a title.
How do you design an experiment?
F. Analysis/Conclusions
1.
2.
3.
Answers the purpose
question.
Accepts or rejects the
hypothesis.
Explains what can be
inferred from the data.
Design an Experiment YouTube
How do we know it is “good science”?
A. Scientific knowledge must be shared, which
allows other scientists to repeat and verify
the work of others (peer review).
A. Scientific knowledge is tentative.
1. Theories are the most logical explanation based on
current evidence, become stronger as more evidence
is gathered, and give us a basis for prediction.
2. Laws are universal generalizations that are virtually
unchanging.
How do you know something is alive?
•
•
A. Biology means the study of (-ology) all life
(bio-) and includes many branches.
B. Biologists organize living things into
kingdoms. There are currently six kingdoms
Kingdom
Example
Archaebacteria
Extremophile bacteria
Eubacteria
Typical bacteria
Protista
Seaweed, Amoeba, Slime Mold
Fungi
Yeast, Mushrooms
Plantae
Moss, Fern, Holly, Oak tree
Animalia
, Fish, Birds, Frogs, Humans
How do you know something is alive?
B. Characteristics of Life - Alive! Videoclip
1. Organization (The level of complexity)
a.
Organism
Organ System
Organs
Tissues
Cells
Molecules
Atoms / Elements
Meet the Elements - They Might Be Giants
How do you know something is alive?
b. All living things need
six essential elements
(atoms): Carbon,
Hydrogen, Nitrogen,
Oxygen, Phosphorus,
Sulfur (CHNOPS)
c. All living things are
made of cells.
b. One-celled
organism –
unicellular
c. Many-celled
organism multicellular
electron
neutron
proton
How do you know something is alive?
•
2. Energy Use
a. Organisms need energy constantly
to build molecules (synthesis) and
cells and to break down (digest)
substances (such as breaking down
food for nutrition)
b. Organisms must transport nutrients
to be used in cellular respiration to
produce energy.
c. An organisms’ chemical reactions
are called its metabolism
How do you know something is alive?
•
3. Reproduction
a. Organisms must
replace themselves so
the entire species will
survive.
b. May be asexual (only
one individual
contributes genetic
material) or sexual
(two individuals
contribute genes).
How do you know something is alive?
•
4. Growth and Development
a. Growth – to increase in size. Increases the number of cells
of a multicellular organism.
b. Development – change that takes place in structure and
function of an organism during its life cycle.
Example: Embryo becomes a fetus
How do you know something is alive?
5. Respond to Stimuli
a. A quick, nonpermanent change
b. Stimulus – any
condition that causes
an organism to react.
Example – A loud noise (stimulus) causes
your dog to run under the bed
(response).
How do you know something is alive?
6. Adjust to Environment
•
a.Homeostasis - the
regulation of an
organism’s internal
environment to
maintain conditions
suitable for life
Ex: Getting rid of wastes
by excretion
How do you know something is alive?
• b. An adaptation is an
inherited structure,
behavior, or internal
process that enables
organisms to better
survive an environment.
• Ex: Gills on a fish
Life Processes: STERNGRR
•
•
•
•
•
•
•
•
Synthesis – making materials
Transport – moving materials
Excretion – getting rid of wastes
Respiration – gas exchange AND production of
energy (ATP)
Nutrition – gaining and using energy from food
Growth and Development – getting bigger and/or
changing
Regulation – controlling internal processes
Reproduction – producing new cells or new
organisms