1. Chapter 1
Introduction: Themes in the
Study of Life

2. Big Picture
•Evolution: the process of change
that has transformed life on Earth.
•Biology: the scientific study of life.
•It is about asking questions:
•HOW?
•WHY?

3. Themes in Biology

4. Order
Evolutionary
adaptation
Response
to the
environment
Reproduction
Growth and
development
Energy
processing
Regulation

5. 8 Themes of AP Biology
1. Science as a Process
2. Evolution
3. Energy Transfer
4. Continuity and Change
5. Relationship of Structure to Function
6. Regulation
7. Interdependence in Nature
8. Science, Technology, and Society

6. Concept 1.1
Themes connect the concepts of
biology.

7. Evolution
•Overarching theme of biology.
•Makes sense of everything we
know about living organisms.
•All organisms living on Earth are
modified descendants of common
ancestors.

8. Biological Hierarchy
•Life at different levels.
The biosphere
Communities
Populations
Organisms
Ecosystems
Organs and organ
systems
Cells
Cell
Organelles
Atoms
Molecules
Tissues
10 µm
1 µm
50 µm

9. Emergent Properties:
• Result from the arrangement and interactions of
parts within a system.

10. Reductionism:
• The reduction of complex systems to simpler
components that are more manageable to study.

11. Systems Biology:
• Constructs models for the dynamic behavior of
the whole biological system – function together.

12. Organisms Interact with their
Environments
•Every organism interacts with its
environment, including nonliving
factors and other organisms.

13. EcosystemDynamics
Sunlight
Ecosystem
Heat
Heat
Cycling
of
chemical
nutrients
Producers
(plants and other
photosynthetic
organisms)
Chemical energy
Consumers
(such as animals)
EnergyConversion

14. Structure and Function
(a) Wings
(c) Neurons
(b) Bones
Infoldings of
membrane
Mitochondrion
(d) Mitochondria
0.5 µm100 µm

15. Cells are the basic unit of
structure and function.
•Lowest level of organization that
can perform all activities required
for life.

16. 1 µm
Organelles
Nucleus (contains DNA)
Cytoplasm
Membrane
DNA
(no nucleus)
Membrane
Eukaryotic cell
Prokaryotic cell

17. Continuity of life is based on heritable
information in the form of DNA
• DNA is the substance of genes.
• Genes are the units of inheritance that transmits
information from parents to offspring.
Nuclei
containing
DNA
Sperm cell
Egg cell
Fertilized egg
with DNA from
both parents
Embryo’s cells with
copies of inherited DNA
Offspring with traits
inherited from
both parents

18. Feedback mechanisms regulate
biological systems
•Negative Feedback: as more of a
product accumulates, the process
that creates is slows and less of the
product is produced.
•Positive Feedback means that as
more of a product accumulates, the
process that creates it speeds up and
more of the product is produced.

19. Excess D
blocks a step
(a) Negative feedback
Negative
feedback
D
D D
D
C
B
A
Enzyme 1
Enzyme 2
Enzyme 3
–

20. Excess Z
stimulates a
step
(b) Positive feedback
Z
Positive
feedback
Enzyme 4
Enzyme 5
Enzyme 6Z
Z
Z
Y
X
W
+

21. Concept 1.2
The Core Theme: Evolution accounts
for the unity and diversity of life.

22. “Nothing in biology makes
sense except in the light of
evolution”—Theodosius
Dobzhansky

23. Organizing the Diversity of Life
•Approximate 1.8 million species have
been identified.
•Estimates of species that actually exist
from 10 to over 100 million.
•Organized in groups: Taxonomy

24. Species Genus Family Order Class Phylum Kingdom Domain
Ursus americanus
(American black bear)
Ursus
Ursidae
Carnivora
Mammalia
Chordata
Animalia
Eukarya

25. (a) DOMAIN BACTERIA
(b) DOMAIN ARCHAEA
(c) DOMAIN EUKARYA
Protists
Kingdom Fungi
Kingdom
Plantae
Kingdom Animalia
ThreeDomainSystem

26. Unity in the Diversity of Life
•A striking unit underlies the diversity
of life:
• DNA is the universal genetic
language common to all organisms.
• Unity is evident in many features of
cell structure.

27. Cilia of
Paramecium
Cross section of a cilium, as viewed
with an electron microscope
Cilia of
windpipe
cells
15 µm 5 µm
0.1 µm

28. Evolution, Darwin and Natural
Selection
• Charles Darwin published On
the Origin of Species by Means
of Natural Selection in 1859
• Darwin made two main points:
• Species showed evidence of
“descent with modification”
from common ancestors
• Natural selection is the
mechanism behind “descent
with modification”

29. Darwin observed that:
• Individuals in a population have traits
that vary
• Many of these traits are heritable
(passed from parents to offspring)
• More offspring are produced than
survive
• Competition is inevitable
• Species generally suit their environment

30. Darwin inferred that:
• Individuals that are best suited to their
environment are more likely to survive
and reproduce
• Over time, more individuals in a
population will have the advantageous
traits
• In other words, the natural environment
“selects” for beneficial traits

31. Population
with varied
inherited traits.
Elimination
of individuals
with certain
traits.
Reproduction
of survivors.
Increasing
frequency
of traits that
enhance
survival and
reproductive
success.
4321

32. Darwin proposed that natural
selection could cause an ancestral
species to give rise to two or more
descendent species

33. COMMON
ANCESTOR
Warblerfinches
Insect-eaters
Seed-eater
Bud-eater
Insect-eaters
Treefinches
Green warbler finch
Certhidea olivacea
Gray warbler finch
Certhidea fusca
Sharp-beaked
ground finch Geospiza
difficilis
Vegetarian finch
Platyspiza crassirostris
Mangrove finch
Cactospiza heliobates
Woodpecker finch
Cactospiza pallida
Medium tree finch
Camarhynchus pauper
Large tree finch
Camarhynchus
psittacula
Small tree finch
Camarhynchus
parvulus
Large cactus
ground finch
Geospiza conirostris
Cactus ground finch
Geospiza scandens
Small ground finch
Geospiza fuliginosa
Medium ground finch
Geospiza fortis
Large ground finch
Geospiza magnirostris
Groundfinches
Seed-eaters
Cactus-flower-
eaters

34. Concept 1.3:
Scientists use two main forms of
inquiry in their study of nature

35. •Inquiry is the search for
information and explanation
•There are two main types of
scientific inquiry: discovery
science and hypothesis-based
science

36. Discovery Science
• This approach is based on
observation and the
analysis of data
• Data fall into two
categories
• Qualitative, or descriptions
rather than measurements
• Quantitative, or recorded
measurements, which are
sometimes organized into
tables and graphs

37. Inductive Reasoning
•Inductive reasoning draws
conclusions through the logical
process of induction
•Scientific method…

38. Observations
Question
Hypothesis #1:
Dead batteries
Hypothesis #2:
Burnt-out bulb

39. Test prediction
Hypothesis #1:
Dead batteries
Hypothesis #2:
Burnt-out bulb
Test prediction
Prediction:
Replacing batteries
will fix problem
Prediction:
Replacing bulb
will fix problem
Test falsifies hypothesis Test does not falsify hypothesis

40. Deduction: Logic of Hypothesis
Based Science
• Deductive reasoning uses general
premises to make specific predictions
• For example, if organisms are made of
cells (premise 1), and humans are
organisms (premise 2), then humans are
composed of cells (deductive prediction)

41. •A hypothesis must be testable
and falsifiable
•Failure to falsify a hypothesis
does not prove that hypothesis

42. The Myth of the Scientific Method
• The scientific method is an idealized
process of inquiry
• Hypothesis-based science is based on the
“textbook” scientific method but rarely
follows all the ordered steps
• Discovery science has made important
contributions with very little dependence
on the so-called scientific method

43. Limitations of Science
•In science, observations and
experimental results must be
repeatable
•Science cannot support or falsify
supernatural explanations, which are
outside the bounds of science