Transcript CHAPTER 1-INTRODUCTION

CHAPTER 1-INTRODUCTION
1.1 – Levels of Organization
Where life is found on
A. Biosphere
earth
B. Ecosystem All organisms + nonliving
components
C. Community All organisms in an area
D. Population Group of individuals of
one species
E. Organisms Individual living thing
F. Organ Systems Composed of related
organs
G. Organs
Individual body parts
H. Tissues Group of similar cells
I. Cells
Unit of living matter
surrounded by membrane
J. Molecule
Cluster of atoms
Characteristics of Life
Organisms need sources of energy so their
metabolism can function.
a) Photosynthesis transforms solar energy in to
chemical energy
● Must maintain homeostasis
● Organisms respond to their environment
● They need to be able to reproduce
a) Pass on their genes to offspring
● Organisms have adaptations that help them
to survive

Theory of Evolution
A. Theory - a comprehensive idea with great
explanatory power
B. Darwin’s Theory of Natural Selection:
1. Organisms have heritable variations
2. They are exposed to an environment
that favors the reproductive success of
some varieties over others.
3. Next generation can be different from
the first.
4. This goes on over many generations
leading to big changes.
C. Adaptations
1. Inherited characteristics that
enhance an organism’s ability to
survive and reproduce in a
particular environment.
2. Examples:
a. Body armor on pangolin
b. Its long tongue to eat
termites with
c. Blow hole on top of head of
marine mammals
1.2 – How Biosphere is
Organized
A.
B.
C.
See previous levels of organization section
Biodiversity is the total number and relative
abundance or species in an ecosystem
Extinction inherently lowers the biodiversity
of any ecosystem.
Humans may be the cause of the greatest
mass extinction event in the Earth’s history
Interconnecting Webs
A. All organisms and the environment are
connected in a complex web of relationships.
B. Examples:
1. Plants - provide food, trap CO2, absorb
nutrients from soil
2. Animals - eats plants & other animals
3. Decomposers - recycle dead matter back
to nutrients used by plants
Differences between Flow of
Energy and Nutrients
NUTRIENTS
Move from air and
soil to plants, to
animals, back to
air and soil
Nutrients are
said to CYCLE.
ENERGY
Flows in from sun
continuously, gets
trapped by plants,
eaten by animals,
and decomposed
with heat lost along
the way
Energy SHUTTLES
Nutrient Cycling & Energy Flow
Loss of
Heat Energy
Air
Cycling
Organisms
of
Nutrients
Soil
Chemical Energy Created
and Used
Light
Energy
1.3 – How Living Things are
Organized
A. Taxonomy is the discipline that identifies
organisms and attempts to classify them into
groups based on common characteristics or other
rules.
B. Ways of grouping organisms:
1. Domains - highest group
a. Bacteria
b. Archaea
c. Eukarya
---
Prokaryotes - no
nucleus
Have nucleus &
organelles
C. Levels of Classification
1.
2.
3.
4.
5.
6.
7.
8.
(From most inclusive to least inclusive)
Domains
Kingdom
Phylum
Class
Order
Family
Genus
Species
D. Eukarya Kingdoms
1. Protists - consist of algae & protozoans
a. Algae - mostly one-celled; do
photosynthesis
b. Protozoans - one-celled; must
eat food
2. Plants - multicellular; photosynthetic;
cells walls made of cellulose
3. Fungi - molds, yeasts, mushrooms.
Decomposers.
4. Animals – multicellular; must eat; motile; no cell
walls
E. Binomial Nomenclature
Scientists assign each living organism a twopart name; a scientific name.
a) First word is the genus
b) Second word is the species epithet
Examples:
Homo sapiens
Canus lupus
Sceloporus jarrovi
Tyrannosaurus rex
1.4– Process of Science
A. Observations – Looking at the world
B. Questions – What do observations
mean?
C. Hypothesis – testable explanation
Can be falsified but NOT proven.
D. Predictions – stating the results of a
hypothesis in advance of a test
E. Test (Experiment) - A method of
determining if a hypothesis is correct or
not
Controlled Experiment
1. Process of carrying out two parallel tests:
a. Experimental group – gets the treatment
b. Control group – no experiment treatment
2. Experimental group should differ from the
control group by only a single factor, called
the independent, or experimental, variable.
Everything else in experiment must be controlled
for and be exactly the same.
3. You measure one or more factors which are called
the dependent, or responding variables.
4. Is Science Proof of Hypotheses?
a. No. All knowledge is open to
reinterpretation. Science amasses
supporting evidence concerning
testable hypotheses
b. Hypotheses can be falsified and
then modified &/or discarded.
c. They are never proven 100% sure.