Download File

1
Chapter 1
Introduction: Biology Today
PowerPoint® Lectures for
Campbell Essential Biology, Fifth Edition, and
Campbell Essential Biology with Physiology,
Fourth Edition
– Eric J. Simon, Jean L. Dickey, and Jane B. Reece
Lectures by Edward J. Zalisko
© 2013 Pearson Education, Inc.
THE SCOPE OF LIFE
2
The Properties of Life
• Biology is the scientific study of life.
– What is life?
• The study of biology encompasses
– a wide scale of size and
– a huge variety of life, both past and present.
© 2013 Pearson Education, Inc.
Properties of Life:
3
1) Order
2) Regulation
3) Growth and delopment
4) Energy Processing
5) Respons to the Environment
6) Reproduction
7) Evolution
1
Properties of Life:
4
1) Order
– All living things exhibit complex but ordered
organization
Properties of Life:
5
2) Regulation
– The environment outside an organism may change
drastically, but the organism can adjust its internal
environment,
Properties of Life:
6
3) Growth and development
– Information carried by DNA controls the pattern of
growth and development
2
Properties of Life:
7
4) Energy processing
– Organisms take in energy and use it to perform all
of life’s activities; they emit energy as heat
Properties of Life:
8
5) Response to the environment
– All organisms respond to environmental stimuli.
Properties of Life:
9
6) Response to the environment
– Organisms reproduce their own kind
3
10
Properties of Life:
7) Evolution
– Reproduction underlies the capacity of populations
to change (evolve) over time.
11
Life at Its Many Levels
• Biologists explore life at levels ranging from the
biosphere to the molecules that make up cells.
© 2013 Pearson Education, Inc.
12
Life at Its Many Levels
• Biologists explore life at levels ranging from the
biosphere to the molecules that make up cells.
1)
Biosphere
2)
Ecosystems
3)
Communities
4)
Populations
5)
Organisms
6)
Organ Systems and Organs
7)
Tissues
8)
Cells
9)
Organelles
Emergent properties:
•
At each level novel properties
emerge from the specific
arrangement and interactions of the
parts in an increasingly
sophisticated system.
•
In simple terms the sum is greater
than the parts
–
Car analogy
10) Molecules and Atoms
4
Life at Its Many Levels
13
• Biologists explore life at levels ranging from the
biosphere to the molecules that make up cells.
1)
Biosphere
2)
Ecosystems
3)
Communities
4)
Populations
5)
Organisms
6)
Organ Systems and Organs
7)
Tissues
8)
Cells
9)
Organelles
10) Molecules and Atoms
Life at Its Many Levels
14
• Biologists explore life at levels ranging from the
biosphere to the molecules that make up cells.
1)
Biosphere
2)
Ecosystems
3)
Communities
4)
Populations
5)
Organisms
6)
Organ Systems and Organs
7)
Tissues
8)
Cells
9)
Organelles
10) Molecules and Atoms
Life at Its Many Levels
15
• Biologists explore life at levels ranging from the
biosphere to the molecules that make up cells.
1)
Biosphere
2)
Ecosystems
3)
Communities
4)
Populations
5)
Organisms
6)
Organ Systems and Organs
7)
Tissues
8)
Cells
9)
Organelles
10) Molecules and Atoms
5
Life at Its Many Levels
16
• Biologists explore life at levels ranging from the
biosphere to the molecules that make up cells.
1)
Biosphere
2)
Ecosystems
3)
Communities
4)
Populations
5)
Organisms
6)
Organ Systems and Organs
7)
Tissues
8)
Cells
9)
Organelles
10) Molecules and Atoms
Life at Its Many Levels
17
• Biologists explore life at levels ranging from the
biosphere to the molecules that make up cells.
1)
Biosphere
2)
Ecosystems
3)
Communities
4)
Populations
5)
Organisms
6)
Organ Systems and Organs
7)
Tissues
8)
Cells
9)
Organelles
10) Molecules and Atoms
Life at Its Many Levels
18
• Biologists explore life at levels ranging from the
biosphere to the molecules that make up cells.
1)
Biosphere
2)
Ecosystems
3)
Communities
4)
Populations
5)
Organisms
6)
Organ Systems and Organs
7)
Tissues
8)
Cells
9)
Organelles
10) Molecules and Atoms
6
19
Life at Its Many Levels
• Biologists explore life at levels ranging from the
biosphere to the molecules that make up cells.
1)
Biosphere
2)
Ecosystems
3)
Communities
4)
Populations
5)
Organisms
6)
Organ Systems and Organs
7)
Tissues
8)
Cells
9)
Organelles
10) Molecules and Atoms
20
Life at Its Many Levels
• Biologists explore life at levels ranging from the
biosphere to the molecules that make up cells.
1)
Biosphere
2)
Ecosystems
3)
Communities
4)
Populations
5)
Organisms
6)
Organ Systems and Organs
7)
Tissues
8)
Cells
9)
Organelles
10) Molecules and Atoms
21
Life at Its Many Levels
• Biologists explore life at levels ranging from the
biosphere to the molecules that make up cells.
1)
Biosphere
2)
Ecosystems
3)
Communities
4)
Populations
5)
Organisms
6)
Organ Systems and Organs
7)
Tissues
8)
Cells
9)
Organelles
Nucleus
10) Molecules and Atoms
7
22
Life at Its Many Levels
• Biologists explore life at levels ranging from the
biosphere to the molecules that make up cells.
1)
Biosphere
2)
Ecosystems
3)
Communities
4)
Populations
5)
Organisms
6)
Organ Systems and Organs
7)
Tissues
8)
Cells
9)
Organelles
Atom
10) Molecules and Atoms
Ecosystems
23
• Each organism interacts continuously with its
environment.
– Organisms interact continuously with the living and
nonliving factors in the environment.
– All the living organisms in a specific area, along
with all of the nonliving factors with which they
interact, form an ecosystem.
© 2013 Pearson Education, Inc.
Ecosystems
24
• The dynamics of any ecosystem depend on two
main processes:
– recycling of chemical nutrients and
– flow of energy.
• Within ecosystems
– nutrients are recycled but
– energy flows through.
© 2013 Pearson Education, Inc.
8
25
Figure 1.3
Outflow
of heat
energy
ECOSYSTEM
Inflow
of light
energy
Consumers
(animals)
Chemical
energy
(food)
Producers
(plants and other
photosynthetic
organisms)
Cycling
of
nutrients
Decomposers
(in soil)
Cells and Their DNA
26
• The cell is the level at which the properties of life
emerge.
• Cells are the lowest level of structure that can
perform all activities required for life.
• All organisms are composed of cells.
• Cells are the subunits that make up multicellular
organisms such as humans and trees.
© 2013 Pearson Education, Inc.
Cells and Their DNA
27
• All cells share many characteristics.
– All cells are enclosed by a membrane that
regulates the passage of materials between the
cell and its surroundings.
– Every cell uses DNA as its genetic information.
© 2013 Pearson Education, Inc.
9
28
Cells and Their DNA
• We can distinguish two major types of cells:
1. The prokaryotic cell is
– simpler and usually smaller and
– characteristic of bacteria.
2. The eukaryotic cell is
– subdivided by internal membranes into different
functional compartments called organelles and
– found in plants and animals.
© 2013 Pearson Education, Inc.
29
Figure 1.4
Prokaryotic cell (bacterium)
Organelles
• Smaller
• Simpler structure
• DNA concentrated in
nucleoid region, which is
not enclosed by membrane
• Lacks most organelles
Eukaryotic cell
• Larger
• More complex
structure
• Nucleus enclosed
by membrane
• Contains many
types of organelles
Nucleoid
region
Colorized TEM
Nucleus
Cells and Their DNA
30
• All cells use DNA as the chemical material of
genes, the units of inheritance that transmit
information from parents to offspring.
• The chemical language of DNA
– is common to all organisms and
– consists of just four molecular building blocks with
names that are abbreviated as A, G, C, T.
© 2013 Pearson Education, Inc.
10
31
Figure 1.5
The four
chemical
building
blocks of
DNA
A DNA molecule
Cells and Their DNA
32
• Genetic engineering has transformed the
pharmaceutical industry and extended millions of
lives.
© 2013 Pearson Education, Inc.
Figure 1.6
33
11
Cells and Their DNA
34
• The entire “book” of genetic instructions that an
organism inherits is called its genome.
• The nucleus of each human cell packs a genome
that is about 3 billion chemical letters long.
© 2013 Pearson Education, Inc.
Life in Its Diverse Forms
35
• Diversity is a hallmark of life.
– The diversity of known life includes about 1.8
million species that biologists have identified and
named.
– Estimates of the total number of species range
from 10 million to over 100 million.
© 2013 Pearson Education, Inc.
Figure 1.7
36
12
Grouping Species: The Basic Concept
37
• Biodiversity can be beautiful but overwhelming.
• Categorizing life into groups helps us deal with this
complexity.
• Taxonomy is the branch of biology that names
and classifies species.
– It formalizes the hierarchical ordering of organisms
into broader and broader groups.
© 2013 Pearson Education, Inc.
The Three Domains of Life
38
• The three domains of life are
– Bacteria,
– Archaea, and
– Eukarya.
• Bacteria and Archaea have prokaryotic cells.
• Eukarya have eukaryotic cells.
© 2013 Pearson Education, Inc.
The Three Domains of Life
39
• Eukarya include
– Kingdom Plantae,
– Kingdom Fungi,
– Kingdom Animalia, and
– Protists (multiple kingdoms).
• Most plants, fungi, and animals are multicellular.
• Protists are generally single-celled.
© 2013 Pearson Education, Inc.
13
40
The Three Domains of Life
• These three multicellular kingdoms are
distinguished by how they obtain food.
– Plants produce their own sugars and other foods
by photosynthesis.
– Fungi are mostly decomposers, digesting dead
organisms.
– Animals obtain food by ingesting (eating) and
digesting other organisms.
© 2013 Pearson Education, Inc.
41
DOMAIN
BACTERIA
Figure 1.8
DOMAIN EUKARYA
DOMAIN
ARCHAEA
Kingdom Plantae
Kingdom Fungi
Kingdom Animalia
Protists (multiple kingdoms)
Unity in the Diversity of Life
42
• Underlying the diversity of life is a striking unity,
especially at the lower levels of biological
organization.
– For example, all life uses the genetic language
of DNA.
© 2013 Pearson Education, Inc.
14
43
- Genome-wide variation from one human being to another can be up to
0.5% (99.5% similarity)
- Chimpanzees are 96% to 98% similar to humans, depending on how it is
calculated.
- Cats have 90% of homologous genes with humans, 82% with dogs, 80%
with cows, 79% with chimpanzees, 69% with rats and 67% with mice.
- Cows (Bos taurus) are 80% genetically similar to humans
- 75% of mouse genes have equivalents in humans, 90% of the mouse
genome could be lined up with a region on the human genome 99% of mouse
genes turn out to have analogues in humans
- The fruit fly (Drosophila) shares about 60% of its DNA with humans
- About 60% of chicken genes correspond to a similar human gene.
Unity in the Diversity of Life
44
• Underlying the diversity of life is a striking unity,
especially at the lower levels of biological
organization.
– For example, all life uses the genetic language
of DNA.
• Biological evolution accounts for this combination
of unity and diversity.
© 2013 Pearson Education, Inc.
EVOLUTION:
BIOLOGY’S UNIFYING THEME
45
• The history of life is a saga of a constantly
changing Earth billions of years old.
– Fossils document this history.
© 2013 Pearson Education, Inc.
15
46
Figure 1.9
EVOLUTION:
BIOLOGY’S UNIFYING THEME
47
• Life evolves.
– Each species is one twig of a branching tree of
life extending back in time through ancestral
species more and more remote.
– Species that are very similar, such as the brown
bear and polar bear, share a more recent
common ancestor.
© 2013 Pearson Education, Inc.
48
Figure 1.10
Giant panda
Spectacled bear
Ancestral
bear
Sloth bear
Sun bear
Common ancestor
of all modern bears
American black bear
Asiatic black bear
Common ancestor of
polar bear and brown bear
Polar bear
Brown bear
30
25
20
15
10
5
Millions of years ago
16
The Darwinian View of Life
49
• The evolutionary view of life came into focus in
1859 when Charles Darwin published On the
Origin of Species by Means of Natural Selection.
© 2013 Pearson Education, Inc.
50
Figure 1.11a
The Darwinian View of Life
51
• Darwin’s book developed two main points:
1. Species living today descended from a succession
of ancestral species in what Darwin called
“descent with modification,” capturing the duality
of life’s
– unity (descent) and
– diversity (modification).
2. Natural selection is the mechanism for descent
with modification.
© 2013 Pearson Education, Inc.
17
Natural Selection
52
• Darwin was struck by the diversity of animals on
the Galápagos Islands.
• He thought that adaptation to the environment and
the origin of new species were closely related
processes.
– As populations separated by a geographic barrier
adapted to local environments, they became
separate species.
© 2013 Pearson Education, Inc.
Darwin’s Inescapable Conclusion
53
• Darwin synthesized the theory of natural selection
from two observations that were neither profound
nor original.
– Others had the pieces of the puzzle, but Darwin
could see how they fit together.
© 2013 Pearson Education, Inc.
Darwin’s Inescapable Conclusion
54
• Observation 1: Overproduction and competition
• Observation 2: Individual variation
• Conclusion: Unequal reproductive success
– It is this unequal reproductive success that Darwin
called natural selection.
– The product of natural selection is adaptation.
• Natural selection is the mechanism of evolution.
© 2013 Pearson Education, Inc.
18
55
Figure 1.12a
1 Population with varied inherited traits
2 Elimination of individuals with certain traits
56
Figure 1.12b
3 Reproduction of survivors
4 Increasing frequency of traits that enhance
survival and reproductive success
Adaptation
57
• The beetles are said to have adapted to their
environment
• However, it is the beetle population that evolved
and adapted. Individuals do not evolve.
© 2013 Pearson Education, Inc.
19
58
Observing Artificial Selection
• Artificial selection vs natural selection
• Artificial selection is the selective breeding of
domesticated plants and animals by humans.
• In artificial selection, humans do the selecting
instead of the environment.
© 2013 Pearson Education, Inc.
59
Figure 1.13a
(a) Vegetables descended
from wild mustard
Wild mustard
Cabbage
from
end buds
Brussels
sprouts from
side buds
Kohlrabi
from stems
Kale from
leaves
Broccoli from
flowers
and stems
Cauliflower
from flower
clusters
60
Figure 1.13b
(b) Domesticated dogs
descended from wolves
Gray wolves
Domesticated dogs
20
Observing Natural Selection
61
• There are many examples of natural selection in
action.
– In Galápagos finches, beak size becomes better
suited to the size and shape of available seeds.
– Antibiotic-resistance in bacteria evolves in
response to the overuse of antibiotics.
© 2013 Pearson Education, Inc.
Observing Natural Selection
62
• Darwin’s publication of The Origin of Species
fueled an explosion in biological research.
– Evolution is one of biology’s best demonstrated,
most comprehensive, and longest-lasting theories.
– Evolution is the unifying theme of biology.
© 2013 Pearson Education, Inc.
THE PROCESS OF SCIENCE
63
• The word science is derived from a Latin verb
meaning “to know.”
– Science is a way of knowing, based on inquiry.
– Science developed from our curiosity about
ourselves and the world around us.
© 2013 Pearson Education, Inc.
21
THE PROCESS OF SCIENCE
64
• There are two main scientific approaches:
– Discovery science is mostly about describing nature.
– Hypothesis-driven science is mostly about
explaining nature.
© 2013 Pearson Education, Inc.
Discovery Science
65
• Science seeks natural causes for natural
phenomena.
– This limits the scope of science to the study of
structures and processes that we can observe and
measure directly or indirectly.
• The dependence on observations that people can
confirm demystifies nature and distinguishes
science from belief in the supernatural.
© 2013 Pearson Education, Inc.
Discovery Science
66
• Verifiable observations and measurements are the
data of discovery science.
– In biology, discovery science enables us to
describe life at its many levels, from ecosystems
down to cells and molecules.
© 2013 Pearson Education, Inc.
22
Figure 1.14a
67
Figure 1.14b
68
Discovery Science
69
• Discovery science
– can stimulate us to ask questions and seek
explanations and
– uses a process of inquiry called the scientific
method, consisting of a series of steps that provide
a loose guideline for scientific investigations.
© 2013 Pearson Education, Inc.
23
70
Hypothesis-Driven Science
• Most modern scientific investigations can be
described as hypothesis-driven science.
– A hypothesis is a tentative answer to a question—
an explanation on trial.
– Although we don’t think of it in those terms, we use
hypotheses in solving everyday problems, like
figuring out why a TV remote fails.
© 2013 Pearson Education, Inc.
71
Hypothesis-Driven Science
• Once a hypothesis is formed, an investigator can
use logic to test it.
– A hypothesis is tested by performing an
experiment to see whether results are as
predicted.
– This deductive reasoning takes the form of
“If…then” logic.
© 2013 Pearson Education, Inc.
72
Hypothesis-Driven Science
• The mysterious case of the broken remote
Observation
The remote
doesn’t
work.
Question
What’s
wrong?
Hypothesis
The
batteries
are dead.
Prediction
With new
batteries, it
will work.
24
73
Hypothesis-Driven Science
• The mysterious case of the broken remote
Observation
The remote
doesn’t
work.
Question
What’s
wrong?
Hypothesis
The
batteries
are dead.
Prediction
With new
batteries, it
will work.
Experiment
Replace
batteries.
Experiment
supports
hypothesis;
make more
predictions
and test.
74
Hypothesis-Driven Science
Observation
The remote
doesn’t
work.
Question
What’s
wrong?
Revise.
Experiment
does not
support
hypothesis.
Hypothesis
The
batteries
are dead.
Prediction
With new
batteries, it
will work.
Experiment
Replace
batteries.
Experiment
supports
hypothesis;
make more
predictions
and test.
The Process of Science:
Are Trans Fats Bad for You?
• One way to better understand how the process of
science can be applied to real-world problems is to
examine a case study, an in-depth examination of
an actual investigation.
© 2013 Pearson Education, Inc.
25
The Process of Science:
Are Trans Fats Bad for You?
76
• Dietary fat comes in different forms.
• Trans fats are a non-natural form produced through
manufacturing processes called hydrogenation.
• Trans fats
– add texture,
– increase shelf life, and
– are inexpensive to prepare.
© 2013 Pearson Education, Inc.
The Process of Science:
Are Trans Fats Bad for You?
77
• A study of 120,000 female nurses found that a diet
with high levels of trans fats nearly doubled the risk
of heart disease.
© 2013 Pearson Education, Inc.
The Process of Science:
Are Trans Fats Bad for You?
78
• A hypothesis-driven study published in 2004
– started with the observation
– that human body fat retains traces of consumed
dietary fat,
– asked the question
– Would the adipose tissue of heart attack patients be
different from a similar group of healthy patients?
– formed the hypothesis
– healthy patients’ body fat would contain less trans fats
than the body fat in heart attack victims.
© 2013 Pearson Education, Inc.
26
79
The Process of Science:
Are Trans Fats Bad for You?
• Design experiment:
– The researchers set up an experiment to determine the
amounts of fat in the adipose tissue of 79 patients who
had experienced a heart attack.
• Collect data and analyze:
– They compared these patients to the data for 167
patients who had not experienced a heart attack.
• This is an example of a controlled experiment
– in which the control and experimental groups differ only
in one variable—the occurrence of a heart attack.
© 2013 Pearson Education, Inc.
80
The Process of Science:
Are Trans Fats Bad for You?
• The results showed significantly higher levels of
trans fats in the bodies of the heart attack patients.
© 2013 Pearson Education, Inc.
81
Trans fats in adipose tissue
(g trans fat per 100 g total fat)
Figure 1.16
2.0
1.77
1.48
1.5
1.0
0.5
0
Heart attack
patients
Control
group
27
The Process of Science:
Are Trans Fats Bad for You?
82
• The results showed significantly higher levels of
trans fats in the bodies of the heart attack patients.
• You would do well to read nutrition labels and
avoid trans fats as much as possible in your own
diet.
© 2013 Pearson Education, Inc.
Theories in Science
83
• What is a scientific theory, and how is it different
from a hypothesis?
– A scientific theory is much broader in scope than a
hypothesis.
– Theories only become widely accepted in science if
they are supported by an accumulation of extensive
and varied evidence.
© 2013 Pearson Education, Inc.
Theories in Science
84
• Scientific theories are not the only way of “knowing
nature.”
• Science, religion, and art are very different ways of
trying to make sense of nature.
© 2013 Pearson Education, Inc.
28
The Culture of Science
85
• Scientists build on what has been learned from
earlier research.
– They pay close attention to contemporary
scientists working on the same problem.
• Cooperation and competition characterize the
scientific culture.
– Scientists check the conclusions of others by
attempting to repeat experiments.
– Scientists are generally skeptics.
© 2013 Pearson Education, Inc.
Science, Technology, and Society
86
• Science and technology are interdependent.
– New technologies advance science.
– Scientific discoveries lead to new technologies.
– For example, the discovery of the structure of
DNA about 60 years ago led to a variety of DNA
technologies.
© 2013 Pearson Education, Inc.
Figure 1.17
87
29
The Culture of Science
88
• Science has two key features that distinguish it
from other forms of inquiry. Science
– depends on observations and measurements that
others can verify and
– requires that ideas (hypotheses) are testable by
experiments that others can repeat.
© 2013 Pearson Education, Inc.
Figure 1.18
Science, Technology, and Society
89
90
– Technology has improved our standard of living
in many ways, but it is a double-edged sword.
– Technology that keeps people healthier has
enabled the human population to double to
7 billion in just the past 40 years.
– The environmental consequences of this
population growth may be devastating.
© 2013 Pearson Education, Inc.
30
Evolution Connection:
Evolution in Our Everyday Lives
91
• Antibiotics are drugs that help cure bacterial
infections.
• When an antibiotic is taken, most bacteria are
typically killed.
• Those bacteria most naturally resistant to the drug
can still survive.
• Those few resistant bacteria can soon multiply and
become the norm and not the exception.
© 2013 Pearson Education, Inc.
Evolution Connection:
Evolution in Our Everyday Lives
92
• The evolution of antibiotic-resistant bacteria is a
huge problem in public health.
• Antibiotics are being used more selectively.
• Many farmers are reducing the use of antibiotics in
animal feed.
© 2013 Pearson Education, Inc.
Evolution Connection:
Evolution in Our Everyday Lives
93
• It is important to note that the adaptation of
bacteria to an environment containing an antibiotic
does not mean that the drug created the antibiotic
resistance. Instead, the environment screened the
heritable variations that already existed among the
existing bacteria.
© 2013 Pearson Education, Inc.
31
94
Colorized SEM
Figure 1.19
32