Download Life at Its Many Levels

General Biology 1004 Chapter 1 Lecture Handout, Summer 2005
Dr. Frisby
Slide 1
THE SCOPE OF BIOLOGY
Biology is the scientific study of life
Slide 2
Life at Its Many Levels
Biologists explore life at
levels ranging from the
biosphere to the molecules
that make up cells
Slide 3
Ecosystems
Each organism interacts continuously with its
environment
General Biology 1004 Chapter 1 Lecture Handout, Summer 2005
Dr. Frisby
Slide 4
Sunlight
Ecosystem
The dynamics of any
ecosystem depend on
two processes
Heat
Consumers
(such as animals)
Heat
Producers
(plants and other
photosynthetic
organisms)
Chemical
energy (food)
Figure 1.3
Slide 5
Sunlight
Ecosystem
Energy flows one way
(from sunlight to producers
to consumers)
Heat
Consumers
(such as animals)
Heat
Producers
(plants and other
photosynthetic
organisms)
Chemical
energy (food)
Nutrients are recycled
(Between producers,
consumers and
decomposers)
Slide 6
The biosphere is enriched bya great
diversity of ecosystems including,
Figure 1.3
General Biology 1004 Chapter 1 Lecture Handout, Summer 2005
Dr. Frisby
Slide 7
Slide 8
Humans are organisms that now have
some presence, often disruptive, in all
ecosystems
Remember, an ecosystem consists of all the
organisms and nonliving factors affecting life
in a particular area.
And, all organisms are
composed of Cells
Slide 9
A cell is the lowest level of structure that
can perform all activities required for life,
including the capacity to reproduce.
General Biology 1004 Chapter 1 Lecture Handout, Summer 2005
Dr. Frisby
Slide 10
A cell is the lowest level of structure that
can perform all activities required for life,
including the capacity to reproduce.
The ability of cells to divide to form new cells is
the basis for:
Slide 11
We can distinguish two major types of cells
Prokaryotic
Eukaryotic
Slide 12
The prokaryotic cell is
simple and contains no
internal membraneous
organelles
They do not contain
a nucleus
The eukaryotic cell
is more complex and
contains organelles
The nucleus is
the largest
organelle in most
eukaryotic cells
Nucleus
(contains
DNA)
Eukaryotic cell
Prokaryotic cell
DNA
(no nucleus)
Organelles
Figure 1.4
General Biology 1004 Chapter 1 Lecture Handout, Summer 2005
Dr. Frisby
Slide 13
All cells use DNA as the
chemical material of genes
Slide 14
The language of DNA
contains just four letters
A, G, C, T
Slide 15
A genome is the entire “book” of genetic
instructions an organism inherits
The nucleus of each human cell
packs a genome that is about 3.2
billion chemical letters long
General Biology 1004 Chapter 1 Lecture Handout, Summer 2005
Dr. Frisby
Slide 16
The emerging field of genomics is a striking
example of human curiosity about life at its many
levels
- Genomics is the branch of biology that
studies whole genomes
Slide 17
Life in Its Diverse Forms
Diversity is the hallmark of life
The diversity of known life includes 1.7 million
species
– Estimates of the total diversity range from 5
million to over 30 million species
Slide 18
Grouping Species: The Basic Concept
Biodiversity can be
both beautiful and
overwhelming
Figure 1.7
General Biology 1004 Chapter 1 Lecture Handout, Summer 2005
Dr. Frisby
Slide 19
Grouping Species: The Basic Concept
Biodiversity
Taxonomy
Figure 1.7
Slide 20
The Three Domains of Life
Domain Bacteria
Domain Archaea
The three domains
of life are
Bacteria
Archaea
Eukarya
Domain Eukarya
Kingdom Protista
Kingdom Plantae
Kingdom Fungi
Kingdom Animalia
Figure 1.8.1
Slide 21
• Bacteria and Archaea are both prokaryotic
domains
Domain Bacteria
Domain Archaea
Figure 1.8.2
General Biology 1004 Chapter 1 Lecture Handout, Summer 2005
Dr. Frisby
Slide 22
• Eukarya includes at least four kingdoms
Protista
Plantae
Fungi
Animalia
Domain Eukarya
Kingdom Protista
Kingdom Plantae
Kingdom Fungi
Kingdom Animalia
Figure 1.8.3
Slide 23
Unity in the Diversity of Life
Underlying the diversity of life is a striking
unity, especially at the lower levels of structure
Example: the universal genetic language of DNA
Slide 24
EVOLUTION: BIOLOGY ’S UNIFYING THEME
The history of
life is a saga of
a restless Earth
billions of years
old
Fossils
document this
history
Figure 1.10
General Biology 1004 Chapter 1 Lecture Handout, Summer 2005
Dr. Frisby
Slide 25
• Life evolves
– Each species is one twig of a branching tree of life
extending back in time
Gian t
pan d a
Spectacled
bear
Slo th
bear
Su n
bear
Amer ican
black bear
Asiatic
Po lar
black b ear b ear
Ancestral bear
Slide 26
Br o wn b ear
Figure 1.11
The Darwinian View of Life
The evolutionary
view of life came
into focus in 1859
when Charles
Darwin published
The Origin of
Species
Figure 1.12
Slide 27
• Darwin’s book developed two main points
Descent with modification
Natural selection
General Biology 1004 Chapter 1 Lecture Handout, Summer 2005
Dr. Frisby
Slide 28
Natural Selection
Darwin was struck by the diversity of animals
on the Galápagos Islands
He thought of adaptation to the environment and
the origin of new species as closely related
processes
As populations separated by a geographic barrier
adapted to local environments, they became separate
species
Chapter 1 Study Objectives:
1.
2.
3.
4.
5.
Describe the two main dynamic processes of an ecosystem.
Compare the structure of prokaryotic and eukaryotic cells.
Distinguish between the three domains and four eukaryotic kingdoms of life.
Describe the two main points that Darwin makes in The Origin of Species.
Describe the two observations that led Darwin to his inescapable conclusion. State this
conclusion.
6. Explain how changes in the effectiveness of antibiotics illustrate natural selection.
7. Compare artificial and natural selection, noting similarities and differences.
8. Compare discovery science and hypothesis-driven science. Provide examples of each.
9. Describe the snake mimicry experiment presented in the text, noting the logical steps of
the experimental process.
10. Describe the two key features that distinguish science from other styles of inquiry.
11. Distinguish between a hypothesis and a theory.