The Study of Life
Chapter 1
Week 1
FIGURE 1.2
Formerly called blue-green algae, these (a) cyanobacteria, shown here at 300x magnification
under a light microscope, are some of Earth’s oldest life forms. These (b) stromatolites along
the shores of Lake Thetis in Western Australia are ancient structures formed by the layering of
cyanobacteria in shallow waters. (credit a: modification of work by NASA; credit b: modification
of work by Ruth Ellison; scale-bar data from Matt Russell)
This OpenStax ancillary resource is © Rice University under a CC-BY 4.0 International license; it may be reproduced or modified but must be attributed to OpenStax,
Rice University and any changes must be noted. Any images credited to other sources are similarly available for reproduction, but must be attributed to their sources.
What is Biology?
✘ Study of living organisms and their
interactions with each other and their
environments.
✘ Permeates everyday life
✗ Escherichia coli and Salmonella breakouts
✗ Cures for diseases
✗ Protect the planet
Escherichia coli (E. coli) bacteria, seen in
this scanning electron micrograph, are
normal residents of our digestive tracts that
aid in the absorption of vitamin K and other
nutrients. However, virulent strains are
sometimes responsible for disease
outbreaks. (credit: Eric Erbe, digital
colorization by Christopher Pooley, both of
USDA, ARS, EMU)
Scientific Method
✘ General guideline for doing science
✗ Posing questions and seeking science based
responses.
✗ Logical, rational, problem-solving method.
✘ Question - How? Why?
✗ Testable
✘ Hypothesis - Tentative, testable, suggested
explanation for an observed phenomenon
✗ Hypothesis can become a verified theory.
■ Theory - tested and confirmed explanation for
observation of phenomena.
✗ Falsifiable
✗ Ex. The classroom is warm because no one
turned on the air conditioner.
Scientific Method - cont.
✘ Prediction - If/then statement.
✗ If we turn on the air conditioner
then the room will no longer be
hot.
✘ Controlled experiment
✘ Analysis - Rejecting a hypothesis
does not make others correct. It
just rules out that particular
explanation.
Provisional Assent
✘ Nothing is ever finally proven
✗ Things can be true for now, pending the addition of
new evidence
Provisional Assent
✘ Three principles regarding the scientific
process
✗ Every assertion regarding the natural world is
subject to challenge and revision based solely on
evidence.
✗ Any scientific hypothesis must be falsifiable, or open
to negation through experimentation
✗ Scientific inquiry concerns itself only with natural
explanations for natural phenomenon.
Basic vs. Applied Science
✘ Basic Science
✗ “pure”
✗ expand knowledge regardless of application
✘ Applied Science
✗ “technology”
✗ Use science to solve real-world problems
✘ Connected
✗ Basic scientific study of DNA and replication leads to
the applied science used to identify genetic diseases
✘ Discoveries are sometimes made by
serendipity
✗ Chance
✗ Unplanned
FIGURE 1.8
After Hurricane Ike struck the Gulf Coast in 2008, the U.S. Fish and Wildlife Service
rescued this brown pelican. Thanks to applied science, scientists knew how to
rehabilitate the bird. (credit: FEMA)
This OpenStax ancillary resource is © Rice University under a CC-BY 4.0 International license; it may be reproduced or modified but must be attributed to OpenStax,
Rice University and any changes must be noted. Any images credited to other sources are similarly available for reproduction, but must be attributed to their sources.
FIGURE 1.9
The Human Genome Project was a 13-year collaborative effort among researchers
working in several different fields of science. The project, which sequenced the entire
human genome, was completed in 2003. (credit: the U.S. Department of Energy
Genome Programs (http://genomics.energy.gov))
This OpenStax ancillary resource is © Rice University under a CC-BY 4.0 International license; it may be reproduced or modified but must be attributed to OpenStax,
Rice University and any changes must be noted. Any images credited to other sources are similarly available for reproduction, but must be attributed to their sources.
Reporting Scientific Work
✘ Communication and collaboration is essential
for scientific researchers to be able to expand
and build upon discoveries.
✘ Peer-review/Peer-reviewed manuscripts papers reviewed by colleagues or peers
✗ Experts
✗ Judge whether or not a work is suitable for
publication
✗ Helps to ensure that research is original, significant,
logical, and thorough.
Properties of Life
✘ 9 Characteristics - Viewed as a group define
life.
✗
✗
✗
✗
✗
✗
✗
✗
✗
Order
Sensitivity or Response to the Environment
Reproduction
Adaptation
Growth and Development
Regulation
Homeostasis
Energy Processing
Evolution
Order
✘ Levels of organization
✘ Complexity
✗ multicellular organisms
✗ single-celled organisms
A toad represents a highly
organized structure consisting
of cells, tissues, organs, and
organ systems. (credit:
“Ivengo”/Wikimedia Commons)
Sensitivity/Response to Stimuli
Chemotaxis - Bacteria attracted to a sugar crystal.
Sensitivity/Response to Stimuli
Phototropism - Plants growing towards light.
Sensitivity/Response to Stimuli
Sensitive Briar responding to touch.
Reproduction
✘ Single-celled - cell division
✘ Multicellular - reproductive germ lines that
will join to form new individuals
✘ Genes ensure offspring will belong to the
same species and will have similar
characteristics.
Growth and Development
✘ Change according to specific instructions
found in their DNA
Although no two look alike, these kittens have inherited genes from both parents and
share many of the same characteristics. (credit: Rocky Mountain Feline Rescue)
Regulation
✘ Important to the coordination of functions
✘ Systems interact
✘ Allow response to stimuli and to cope with
environmental stresses
Homeostasis
✘ Maintenance of internal conditions so that
cells can function properly
✗ Temperature
✗ pH
✗ Concentration of chemicals
Polar bears (Ursus maritimus)
and other mammals living in
ice-covered regions maintain
their body temperature by
generating heat and reducing
heat loss through thick fur and
a dense layer of fat under their
skin. (credit:
“longhorndave”/Flickr)
Energy Processing
✘ Obtaining and processing
energy
✗ Plants - sun converted to
chemical energy
✗ Humans - food
✘ Used for metabolic activities
The California condor (Gymnogyps
californianus) uses chemical energy
derived from food to power flight.
California condors are an endangered
species; this bird has a wing tag that helps
biologists identify the individual. (credit:
Pacific Southwest Region U.S. Fish and
Wildlife Service)
Biological Levels of Organization
Classification of Life
✘ Shows relationships among biological species
✘ Based on similarities and differences in
genetic traits, physical traits, or both.
✘ Genetics and genome exploration is playing a
major role in classification and organization of
organisms
✗ Comparison of gene sequences
FIGURE 1.18
These images represent different domains. The (a) bacteria in this micrograph belong to Domain
Bacteria, while the (b) extremophiles (not visible) living in this hot vent belong to Domain Archaea.
Both the (c) sunflower and (d) lion are part of Domain Eukarya. (credit a: modification of work by Drew
March; credit b: modification of work by Steve Jurvetson; credit c: modification of work by Michael
Arrighi; credit d: modification of work by Leszek Leszcynski)
This OpenStax ancillary resource is © Rice University under a CC-BY 4.0 International license; it may be reproduced or modified but must be attributed to OpenStax,
Rice University and any changes must be noted. Any images credited to other sources are similarly available for reproduction, but must be attributed to their sources.