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

69

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