Chp 1 Biology: Exploring Life
1.10
Biology, Technology, & Society are Connected
What current Biology-related news topics have you
read/heard about?
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1.1
All Life Forms Share Common Properties
What common property of life does each picture display?
✶ Sunflower, Macaques, tadpole, hummingbird feeding,
dragonfly on Venus flytrap, Jackrabbit’s ears, Ptarmigan
coloration
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1.2 In
Life’s Hierarchy of Organization, New
Properties Emerge at Each Level
✶ Biology
is the ______________ study of
_________ (at any of its many levels of organization)
18th Century illustration of the bizarre world of microorganisms
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Biosphere
Biosphere
Ecosystem
Florida coast
___________
Community
_____________
Community
Organism
All organisms on
the Florida coast
Population
Biology’s Levels of Organization
Group of brown
pelicans
Organism Brown pelican
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Organ system
Organ
Organism Brown pelican
Spinal cord
Tissue
Organ system
Nervous system
Nerve
Brain
Cell
Organ
Brain
Tissue
Atom
Nervous tissue
Atom
Cell
Nerve cell
Nucleus
Organelle
Nucleus
Molecule
DNA
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✶ The
– – – – upper tier is a global perspective of life
_________________- all the environments on Earth
that support life
_________________- all the organisms and the physical
factors of a particular area
_________________- all of the organisms living in a
particular ecosystem
_________________ - all the individuals of a particular
species within a specific area
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middle tier is characterized by the organism,
an individual living thing, which is composed of
✶ The
– – – _________ ___________- have specific functions; are
composed of multiple organs
_____________- provide specific functions for the
organism; composed of multiple ___________
______________- composed of groups of similar cells
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✶ Life
emerges at the level of the cell, the lower
tier, which is composed of
– – – ___________- living entities distinguished from their
environment by a membrane; fundamental unit of life
_____________ - membrane-bound structures within a
cell that has specific functions
___________________ - clusters of atoms bonded
together
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1.3 Cells
✶ Two
– are the Smallest Units of Life
distinct types of cells exist on our planet
Prokaryotic cells
– Simple
and small
– Bacteria
– are examples of _____________ cells
Eukaryotic cells
– Possess
organelles surrounded by a ______________
– Plants,
animals, and fungi are composed of
______________ cells
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Prokaryotic cell
Eukaryotic cell
DNA
(no nucleus)
Membrane
Nucleus
(contains DNA)
Organelles
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EVOLUTION IS THE CORE THEME IN BIOLOGY
1.6 Diversity
of Life is Arranged into 3 Domains
∗ The 3 ____________ (categories) of life
– Bacteria—prokaryotic, and most are unicellular and
microscopic
– Archaea—like bacteria, are ____________, and most
are unicellular and microscopic
– Eukarya—are ____________ and contain a nucleus
and organelles
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Domain Eukarya
Domain Bacteria
Bacteria (multiple kingdoms)
Protists (multiple kingdoms)
Kingdom Plantae
Domain Archaea
Archaea (multiple kingdoms)
Kingdom Fungi
Kingdom Animalia
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Tree of life: Based on analyzing chemical components of organisms ✶ Earliest
living cells were ____________, then
multicellular ____________ organisms evolved
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1.7 Evolution
Explains Unity & Diversity of Life
1859, __________ __________ published On the
Origin of Species by Means of Natural Selection
✶ In
✶ The
book accomplished two
things
– – Presented evidence to support the
idea of evolution
Proposed a mechanism for
evolution called ______________
____________
Charles Darwin (1809-1882)
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✶ Natural
selection is
an editing process
– – – Individuals within a
_____________ have
inherited variations
Population exposed to
“outside” factors that
favor reproductive
success of some
individuals over others
Over time, this results in
a change in the
________________ =
biological evolution
(1) Population with varied inherited traits
(2) Elimination of individuals with certain traits
(3) Reproduction of survivors
Figure 1.6B Natural selection
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Evolution = “descent with modification”
✶ History
– – of life resembles a multi-branched tree
________ of tree are current living species, twigs and
limbs are lines of descent, branches are
______________ ____________
Living species are descendants of ancestral species
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THE PROCESS OF SCIENCE
1.8 Scientific Inquiry Asks and Answers Questions
About Nature
∗ 2 approaches to understand
natural causes for natural
events
– – Inductive reasoning- draw
general conclusions from
many observations
____________ reasoningcome up with ways to test a
hypothesis and see if results
support the hypothesis
Science: A method of inquiry
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In Science, Hypothesis & Theory are Different
✶ Hypothesis
- a proposed explanation for a set of
observations
✶ Theory
− - an explanatory idea that is
1) ________ in scope 2) Supported by a large body of
____________ and 3) Widely ___________
What is an example of a hypothesis, and a theory
✶ Science
seeks natural causes for natural events
– Limits scope to those structures/processes that
– Can be _________________ and ___________________
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1.9
Scientists Form and Test Hypotheses
✶ Case
– ✶ A
study
Flashlight failure
____________ that
has been tested and
not falsified is
tentatively accepted
Observations
Question
Hypothesis # 1:
Dead batteries
Hypothesis # 2:
Burnt-out bulb
Prediction:
Replacing batteries
will fix problem
Prediction:
Replacing bulb
will fix problem
Test prediction
Test falsifies hypothesis
Test prediction
Test does not falsify hypothesis
Figure 1.8A The hypothesis-based scientific method
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Scientists Conduct Controlled Experiments
✶ Each
factor that might influence a process is a
variable
– To evaluate hypotheses about one variable, all other
variables must be kept constant
experimental group has one variable
altered. In the ____________ group, that
variable is not altered
✶ The
– All other aspects the two groups are identical
✶ Controls are used to make the results of an
____________ meaningful
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✶ Case
study: Spider mimicry
Zebra spider and
snowberry fly.
Pounce rate (% of
trials in which spider
jumped on fly)
What is the hypothesis?
What do these results tell
you about the hypothesis?
Control group
(untreated flies)
Experimental group
(wing markings masked)
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Objective Checklist
! Name the common properties of all life
! Describe life’s hierarchy of organization
! Describe the two types of cells and name some
of their structural features
! Explain the theory of evolution by natural
selection and how current species are
descendants of ancestral species
! Describe the process of hypothesis-based
science
! Describe the difference between a hypothesis
and a theory
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