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AP Biology Chapter 1
A View of Life
Biology - the study of life
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Constantly changing
Increasing quality of life
Drastically changing health care
New discoveries daily
Technology
Themes of Biology
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Evolution of life
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Transmission of information
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Diverse life forms are related
DNA, Chemical signaling
Flow of energy through living systems
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Energy constantly required to maintain
complex processes
Characteristics of Organisms
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Cells – organisms are made of one or
more cells
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Cell Theory:
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All living organisms are composed of cells
New cells arise from existing cells
Cells are basic unit of structure and function of
living things
Schleiden, Schwann, and Virchow
**Cell Theory Video
Characteristics of Organisms
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Organisms grow and develop
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Biological growth - increase in the size of
cells or the number of cells
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Growth may be uniform or greater in some
parts than others
Development - all the changes that take
place during an organism's life
Characteristics of Organisms
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Metabolism - the sum of all the chemical
activities of the organism
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Processes occur continuously in every living
organism
Must be carefully regulated to maintain
homeostasis
Homeostatic mechanisms are control systems that
maintain constant levels of cellular products in the
organism
 Example - regulation of glucose in the blood of
complex animals
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Heterotrophs – organism that obtains
food by consuming other living
organisms
Autotrophs – organism that makes its
own food
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Photosynthesis
Chemosynthesis
**Metabolism Video Clip
Characteristics of Organisms
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Movement - basic property of cells
Many varieties of movement
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Extensions such as cilia (hairlike) and flagella
(longer structures)
Animals move obviously (swim, crawl, run, fly) have complex tissues for movement = muscles!
Even plants move toward the sun or trap
insects
Characteristics of Organisms
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Organisms respond to stimuli
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Stimuli that evoke a response in
organisms:
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Changes in light intensity, direction, or color
Changes in temperature, pressure, or sound
Changes in the chemical composition of the
surrounding soil, air, or water
Plants respond to stimuli too!
Characteristics of Organisms
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Reproduction
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Asexual - exact copy of
parent, ex. bacteria
Sexual - egg and
sperm cells combine to
form a fertilized egg,
provides genetic
variation
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Can be internal or
external fertilization
Characteristics of Organisms
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Adaptations
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Adaptations are traits that enhance an
organism's ability to survive
Every organism is a complex collection of
coordinated adaptations produced through
evolutionary processes
Transmission of Information
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Instructions are needed
to carry out life processes
DNA - genetic material
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Watson and Crick, 1953
Makes up genes - the
hereditary units
Used to specify instructions
for making every living
organism
Transmission of Information
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DNA contains the information to make
all the proteins needed by an organism
Proteins determine the structure and
function of cells and tissues
Cells also use proteins to communicate
with one another
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Cell signaling
*Learning to manipulate cell signaling may lead to
new discoveries in the medicine.
Chemical Transmission of
Information
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Hormones - molecules that function as
chemical messengers that transmit
information from one part of an
organism to another
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Can signal cells to produce a protein or
other substance
Electrical Transmission of
Information
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Nervous Systems
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Electrical Impulses
Neurotransmitters chemical compounds
Ex. Transmit message
from eyes and ears to
the brain
Biological Organization
Smallest
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Hierarchical
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At every level,
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coordinated
Solomon p.9
structure and
function are
Largest
Chemical – atoms
Molecule – atoms combine
Cell – atoms and
molecules form cells
(basic structure of living
things)
Tissue – cells working
together
Organ – tissues organized
Organ System – group of
tissues and organs
Organism – organ
systems working together
Ecological Organization
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Population – all the members of one
species that live in the same geographic
area at the same time
Community – the populations of
organisms that inhabit a particular area
and interact with one another
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Can be hundreds of different organisms
Ecological Organization
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Ecosystem – a community together with
its nonliving environment
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Can vary greatly in size
Biosphere – all of Earth’s ecosystems
together
Ecology – the study of how organisms
relate to one another and to their
environment
Evolutionary Relationships
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Systematics – studies evolutionary
relationships
Taxonomy – the science of naming and
classifying organisms
Binomial nomenclature – each species is
assigned a two-part name
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1st part of name = genus
2nd part of name = specific epithet
Taxonomic Classification
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Remember: King Phillip Came Over For Good
Spaghetti
Kingdom, Phylum, Class, Order, Family,
Genus, Specific epithet
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See page 11 (table 1-1)
3 domains: Archaea, Eubacteria, and Eukarya
6 kingdoms: Plant, Animal, Fungi, Protista
Archaebacteria, Eubacteria
Evolution is the primary
unifying concept of biology
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Theory of evolution explains how
populations change over time
Natural Selection – mechanism by which
evolution proceeds
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Organisms that possess favorable adaptations
to their environment survive and pass on
genes to next generation
Biology is Studied using the
Scientific Method
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Involves a series of ordered steps and is the
framework used by scientists
Scientists make careful observations, ask
critical questions, and develop hypotheses
Then, scientists make predictions, test their
predictions, interpret results, and draw
conclusions
See page 17 (figure 1-16)
Scientific Method
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A properly designed experiment
includes: a control group and
experimental group
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Only differ with respect to the variable
being studied
Must be free of bias!
Scientific Method
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When a number of related hypotheses
have been supported many times,
scientists develop a theory
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A theory is a well researched and
supported scientific statement.
A well established and tested theory
may be referred to as a scientific
principle