Transcript Ch. 1 - Intro to Biology

Chapter 1
Discovery Science
Discovery science
Describes natural
structures and processes
as accurately as possible
through careful
observation and analysis
of data
Data
Are recorded
observations
Can be quantitative or
Figure 1.24
qualitative
Hypothesis-Based Science
In science, inquiry that asks specific
questions
Usually involves the proposing and testing of
hypothetical explanations, or hypotheses
In science, a hypothesis
Is a tentative answer to a well-framed question,
an explanation on trial
Makes predictions that can be tested
In this case study
Mimicry in king snakes is examined
The hypothesis predicts that predators in non–coral
snake areas will attack king snakes more frequently
than will predators that live where coral snakes are
present
Scarlet king snake
Key
Range of scarlet king snake
Range of eastern color snake
North
Carolina
South
Carolina
Eastern coral snake
Figure 1.27
Scarlet king snake
Artificial Snakes
 To test this mimicry hypothesis
Researchers made hundreds of artificial snakes, an
experimental group resembling king snakes and a
control group of plain brown snakes
(a) Artificial king snake
Figure 1.28
(b) Brown artificial snake that has been attacked
After a given period of time
The researchers collected data that fit a key
Key
Key
prediction
% of attacks on artificial king snakes
% of attacks on brown artificial snakes
Field site with artificial snakes
17%
In areas where coral snakes
were absent, most attacks
were on artificial king snakes
83%
X
XX
North
Carolina X
XX
South
X
Carolina X
X
XX
XXX
16%
84%
Figure 1.29
In areas where coral
snakes were present,
most attacks were on
artificial king snakes
Limitations of Science
Science cannot address supernatural
phenomena
Because hypotheses must be testable and
falsifiable and experimental results must be
repeatable
Concept of Scale
 The study of life extends from the microscope scale of
molecules and cells to the global scale of the entire
living planet
Hierarchy of Organization
Molecule
Organelle
Cells
Tissues
Organ
Organism
Population
Community
Ecosystem
Feedback Regulation: Negative
Accumulation of an
end product of a
process slows that
process
Example: sugar
breakdown generates
ATP; excess ATP
inhibits an enzyme
near the beginning of
the pathway
Feedback Regulation: Positive
An end product
speeds up its
production
Example: blood
clotting in response to
injury
Grouping Species
 Taxonomy
(classifying life)
Ursus Species Genus Family
americanus
(American
black bear)
Is the branch of
biology that names
and classifies
species according
to a system of
broader and
broader groups
Order
Class
Phylum Kingdom Domain
Ursus
Ursidae
Carnivora
Mammalia
Chordata
Animalia
Eukarya
The Three Domains of Life
At the highest level, life is classified into three
domains:
Bacteria (prokaryotes)
Archaea (prokaryotes)
Eukarya (eukaryotes)
Eukaryotes include protists and the kingdoms
Plantae, Fungi, and Animalia
LE 1-15
Bacteria
Archaea
4 µm
0.5 µm
Protists
Kingdom Fungi
100 µm
Kingdom Plantae
Kingdom Animalia
Unifying Themes in Biology