Intro: Themes in the Study of Life
BIOL 101 General Biology I
Chapter 1
Rob Swatski Associate Professor of Biology
HACC - York Campus 1
Biologists ask
questions …
2
3
4
Life is…
Order
5
Evolutionary adaptation
6 Response to the environment
7
Reproduction
8 Growth and development
9
Energy processing
10 Regulation
Themes organize & connect biology concepts
Chunk it!!!
11
12
“Nothing in biology makes sense except in the
light of evolution”
Theodosius Dobzhansky
The biosphere
Ecosystems
Tissues
Organs and organ systems
Communities
Populations
Organisms
Organelles Cells
Atoms
Molecules
13
14
Levels of Organization
Organ systems
Organs
Tissue
Cell
Molecule
Atom
15
Biosphere
Ecosystems
Communities
Populations
Organisms
Emergent Properties
16
17
18
19
Complex Simple
Reductionism
Systems Biology
20
21
Interactions
22
Ecosystem Dynamics
Nutrient Cycling
Energy Flow
23
Animals eat
leaves and fruit
from the tree.
Leaves take in carbon dioxide from the air and release oxygen.
Sunlight
CO2
O2
Cycling
of
chemical
nutrients
Leaves fall to the ground and are decomposed by organisms that return minerals to the soil.
Water and minerals in the soil are taken up by the tree through its roots.
Leaves absorb light energy from the sun.
24
Chemical energy
(a) Energy flow from sunlight to producers to consumers
Sunlight
Producers absorb light energy and transform it into chemical energy.
Chemical energy in food is transferred from plants to consumers.
25
Heat
(b) Using energy to do work
When energy is used to do work, some energy is converted to thermal energy, which is lost as heat.
An animal’s muscle cells convert chemical energy from food to kinetic energy, the energy of motion. A plant’s cells use
chemical energy to do work such as growing new leaves.
26
27
Energy
Potential
Chemical Kinetic
28
29
30
31
Structure vs. Function
100 µm
32
33
34
Cell Structure & Function
Plasma membrane
Contain DNA
Able to divide
35
36
Prokaryotes
No organelles
No nucleus
Bacteria & Archaea
Eukaryotes
Organelles present
Nucleus present
Protists, fungi, plants,
animals
37
Eukaryotic cell
Prokaryotic cell
Cytoplasm
DNA (no nucleus)
Membrane
Nucleus
(membrane-
enclosed)
Membrane
Membrane-
enclosed organelles
DNA (throughout
nucleus) 1 m
38
39
DNA
Chromosomes
Genes
Nucleus
DNA
Cell
Nucleotide
(b) Single strand of DNA
A
C
T
T
A
A
T
C
C
G
T
A
G
T
(a) DNA double helix
A
40
41
Genome Gene DNA RNA Protein
42
TRANSCRIPTION DNA
mRNA
TRANSLATION
Protein
43
44
Systems Biology
45 Bioinformatics
46
Homeostasis
47
48
Negative Feedback
Positive Feedback
Negative Feedback System
Decreases stimulus if too high
Increases stimulus if
too low
49
Excess D blocks a step
Negative feedback
Negative feedback
D
D D
D
C
B
A
Enzyme 1
Enzyme 2
Enzyme 3
–
50
51
Positive Feedback System
Excess Z stimulates a step
Positive feedback
Z
Positive feedback
Enzyme 4
Enzyme 5
Enzyme 6 Z
Z
Z
Y
X
W
+
52
Z
Z
53
Evolution accounts for the unity & diversity of life
54
55
Suedberg Fossil Pit Devonian 375 MYA 56
57
58
Species Genus Family Order Class Phylum Kingdom Domain
Ursus americanus (American black bear)
Ursus
Ursidae
Carnivora
Mammalia
Chordata
Animalia
Eukarya
59 Taxonomy
3 Domains of Life
Bacteria Archaea Eukarya
60
Domain Bacteria
61
62
Domain Archaea
63
Domain Eukarya
Kingdom Protista
Kingdom Fungi
Kingdom Plantae
Kingdom Animalia
Kingdom Protista
64
Kingdom Fungi
65
66
Kingdom Plantae
Kingdom Animalia
67
Cilia of Paramecium
Cilia of windpipe
cells
15 µm 5 µm
68
Unity in the Diversity of Life
70
71
72
1859: The Origin of Species by Charles Darwin
73
Don’t Listen to Your Parents
“You care for nothing
but shooting, dogs,
and rat-catching
and you will be a
disgrace to yourself
and your family.”
Dr. Robert Darwin
74
75
Two Main Points of Origin of Species
Descent with
modification
Natural Selection
76
Individuals in a population have traits that vary
Traits are heritable
More offspring are produced then actually survive
Competition is inevitable
Species are generally well adapted to their environment
77
78
79
Adaptations: evidence of natural selection 80
81
82
83
COMMON
ANCESTOR
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
Ins
ec
t-ea
ters
Se
ed
-ea
ter
Bu
d-e
ate
r
Ins
ec
t-ea
ters
Tre
e fin
ch
es
G
rou
nd
finc
he
s
Se
ed
-ea
ters
Cac
tus
-flow
er-
ea
ters
Wa
rble
r finc
he
s
84
85
86
Two Main Types of Scientific Inquiry
Discovery science
Hypothesis-Based science
87
Descriptive Natural
structures & processes
Observation Inductive reasoning
Data analysis Discovery Science
88 Inductive Reasoning
Generalizations are derived from a large number of specific observations
89
Qualitative Quantitative
Types of Data
90
Qualitative Data
91
Quantitative Data
92
Hypothesis-Based Science
Observe
Question
Hypothesize
Predict
Observations
Question
Hypothesis #1:
Dead batteries
Hypothesis #2:
Burnt-out bulb
93
Hypothesis #1:
Dead batteries
Hypothesis #2:
Burnt-out bulb
Prediction:
Replacing bulb
will fix problem
Test of prediction
Test falsifies hypothesis Test does not falsify hypothesis
Prediction:
Replacing batteries
will fix problem
Test of prediction
94
95 Deductive Reasoning
Eastern Coral Snake
96
Scarlet Kingsnake (nonvenomous)
Eastern coral snake (venomous) 97
South Carolina
North Carolina
Key
Scarlet kingsnake (nonvenomous)
Scarlet kingsnake (nonvenomous)
Eastern coral snake (venomous)
Range of scarlet kingsnake only
Overlapping ranges of scarlet kingsnake & eastern coral snake
98
(a) Artificial kingsnake
(b) Brown artificial snake that has been attacked 99
Artificial kingsnakes
Brown artificial snakes
83% 84%
17% 16%
Coral snakes absent
Coral snakes present
Pe
rce
nt
of
tota
l att
acks
o
n a
rtif
icia
l sn
ake
s 100
80
60
40
20
0
RESULTS
100
101
102
What is a Theory?
Broad and general
Supported by lots of evidence
Generates new
testable hypotheses
103
Models
3-D objects
Diagrams
Math equations
Computer programs
The Culture of Science: Creativity
The Culture of Science: Communication
104 The Culture of Science: Teamwork