Which of the topics in this module did you find most relevant to your everyday life?

Which of the topics in this module did you find most relevant to your everyday life? Explain how the topic relates to your life and why it important to you

PowerPoint® Lectures created by Edward J. Zalisko for Campbell Essential Biology, Sixth Edition, and

Campbell Essential Biology with Physiology, Fifth Edition – Eric J. Simon, Jean L. Dickey, Kelly A. Hogan, and Jane B. Reece

Chapter

Introduction:

Biology Today

Biology and Society: An Innate Passion for Life

• Most of us have an inherent interest in life, an inborn curiosity of the natural world that leads us to explore and study animals and plants and their habitats.

Figure 1.0-1

Why Biology Matters

Figure 1.0-1a

Figure 1.0-1b

Figure 1.0-1c

Figure 1.0-2

Biology All Around Us

Biology and Society: An Innate Passion for Life

• Life is relevant and important to you, no matter your background or goals.

• The subject of biology is woven into the fabric of society.

The Scientific Study of Life

• Biology is the scientific study of life. But

• what is a scientific study and

• what does it mean to be alive?

The Process of Science

• How do we tell the difference between science and other ways of trying to make sense of nature?

The Process of Science

• Science is an approach to understanding the natural world that is based on inquiry:

• a search for information,

• explanations, and

• answers to specific questions.

The Process of Science

• This basic human drive to understand our natural world is manifest in two main scientific approaches:

• discovery science, which is mostly about describing nature, and

• hypothesis-driven science, which is mostly about explaining nature.

• Most scientists practice a combination of these two forms of inquiry.

Discovery Science

• Science seeks natural causes for natural phenomena.

• This limits the scope of science to the study of structures and processes that we can

• verifiably observe and

• measure directly or indirectly with the help of tools and technology, such as microscopes.

Figure 1.1

Light Micrograph (LM)

TYPES OF MICROGRAPHS

Scanning Electron Micrograph (SEM)

Transmission Electron Micrograph (TEM)

Figure 1.1-1

Light Micrograph (LM)

Figure 1.1-2

Scanning Electron Micrograph (SEM)

Figure 1.1-3

Transmission Electron Micrograph (TEM)

Discovery Science

• Recorded observations are called data, and data are the items of information on which scientific inquiry is based.

• This dependence on verifiable data

• demystifies nature and

• distinguishes science from supernatural beliefs.

Discovery Science

• Science can neither prove nor disprove that angels, ghosts, deities, or spirits, whether benevolent or evil, cause storms, eclipses, illnesses, or cure diseases, because such explanations are not measurable and are therefore outside the bounds of science.

Discovery Science

• Verifiable observations and measurements are the data of discovery science.

• Charles Darwin’s careful description of the diverse plants and animals he observed in South America is an example of discovery science.

• Jane Goodall spent decades observing and recording the behavior of chimpanzees living in the jungles of Tanzania.

Figure 1.2

Figure 1.2-1

Figure 1.2-2

Hypothesis-Driven Science

• The observations of discovery science motivate us to ask questions and seek explanations.

• As a formal process of inquiry, the scientific method consists of a series of steps that provide a loose guideline for scientific investigations.

Hypothesis-Driven Science

• There is no single formula for successfully discovering something new.

• Instead, the scientific method suggests a broad outline for how discovery might proceed.

Figure 1.3-s1 Applying the scientific method to a common problem (step 1)

Question What’s wrong?

Observation The remote doesn’t work.

Figure 1.3-s2 Applying the scientific method to a common problem (step 2)

Observation The remote doesn’t work.

Question What’s wrong?

Hypothesis The

batteries are dead.

Figure 1.3-s3 Applying the scientific method to a common problem (step 3)

Observation The remote doesn’t work.

Question What’s wrong?

Hypothesis The

batteries are dead.

Prediction With new

batteries, it will work.

Figure 1.3-s4 Applying the scientific method to a common problem (step 4)

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.

Figure 1.3-s5 Applying the scientific method to a common problem (step 5)

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.

Revise.

Experiment does not support

hypothesis.

Hypothesis-Driven Science

• Most modern scientific investigations can be described as hypothesis-driven science.

• A hypothesis is

• a tentative answer to a question or

• a proposed explanation for a set of observations.

• A good hypothesis immediately leads to predictions that can be tested by experiments.

Figure 1.3-s1 Applying the scientific method to a common problem (step 1)

Question What’s wrong?

Observation The remote doesn’t work.

Figure 1.3-s2 Applying the scientific method to a common problem (step 2)

Observation The remote doesn’t work.

Question What’s wrong?

Hypothesis The

batteries are dead.

Figure 1.3-s3 Applying the scientific method to a common problem (step 3)

Observation The remote doesn’t work.

Question What’s wrong?

Hypothesis The

batteries are dead.

Prediction With new

batteries, it will work.

Figure 1.3-s4 Applying the scientific method to a common problem (step 4)

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.

Figure 1.3-s5 Applying the scientific method to a common problem (step 5)

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.

Revise.

Experiment does not support

hypothesis.

Hypothesis-Driven Science

• Once a hypothesis is formed, an investigator can make predictions about what results are expected if that hypothesis is correct.

• We then test the hypothesis by performing an experiment to see whether or not the results are as predicted.

Hypothesis-Driven Science

• The scientific method is therefore just a formalization of how you already think and act.

• Having a firm grasp of science as a process of inquiry can therefore help you in many ways in your life outside the classroom.

Hypothesis-Driven Science

• Scientific investigations are not the only way of knowing nature.

• Science and religion are two very different ways of trying to make sense of nature.

• Art is yet another way to make sense of the world around us.

• A broad education should include exposure to all these different ways of viewing the world.

Theories in Science

• Accumulating facts is not the primary goal of science.

• Facts are

• verifiable observations and repeatable experimental results and

• the prerequisites of science.

Theories in Science

• But what really advances science are new theories that tie together a number of observations that previously seemed unrelated.

• The cornerstones of science are the explanations that apply to the greatest variety of phenomena.

Theories in Science

• People like Isaac Newton, Charles Darwin, and Albert Einstein stand out in the history of science not because they discovered a great many facts but because their theories had such broad explanatory power.

Theories in Science

• What is a scientific theory, and how is it different from a hypothesis?

• A scientific theory is much broader in scope than a hypothesis.

• A theory

• is a comprehensive explanation supported by abundant evidence, and

• is general enough to spin off many new testable hypotheses.

Theories in Science

• For example, these are two hypotheses.

1. “White fur is an adaptation that helps polar bears survive in an Arctic habitat.”

2. “The unusual bone structure in a hummingbird’s wings is an evolutionary adaptation that provides an advantage in gathering nectar from flowers.”

• In contrast, the following theory ties together those seemingly unrelated hypotheses:

• “Adaptations to the local environment evolve by natural selection.”

Theories in Science

• Theories only become widely accepted by scientists if they

• are supported by an accumulation of extensive and varied evidence and

• have not been contradicted by any scientific data.

Theories in Science

• The use of the term theory by scientists contrasts with our everyday usage, which implies untested speculation (“It’s just a theory!”).

• We use the word “theory” in our everyday speech the way that a scientist uses the word “hypothesis.”

The Nature of Life

• What is life?

• What distinguishes living things from nonliving things?

• The phenomenon of life seems to defy a simple, one-sentence definition.

• We recognize life mainly by what living things do.

The Properties of Life

• Figure 1.4 highlights seven of the properties and processes associated with life.

Figure 1.4-1

(a) Order (b) Regulation

Figure 1.4-1a

(a) Order

Figure 1.4-1b

(b) Regulation

Figure 1.4-1c

Figure 1.4-1d

(d) Energy processing

Figure 1.4-2

(f) Reproduction

(e) Response to the environment (g) Evolution

Figure 1.4-2a

(e) Response to the environment

Figure 1.4-2b

(f) Reproduction

Figure 1.4-2c

(g) Evolution

The Properties of Life

• The Mars rover Curiosity

• has been exploring the surface of the red planet since 2012 and

• contains several instruments designed to identify biosignatures, substances that provide evidence of past or present life.

• As of yet, no definitive signs of the properties of life have been detected, and the search continues.

Figure 1.5

Life in Its Diverse Forms

• The tarsier shown in Figure 1.6 is just one of about 1.8 million identified species on Earth that displays all of the properties outlined in Figure 1.4.

Figure 1.6

Life in Its Diverse Forms

• The diversity of known life—all the species that have been identified and named—includes

• at least 290,000 plants,

• 52,000 vertebrates (animals with backbones), and

• 1 million insects (more than half of all known forms of life).

Life in Its Diverse Forms

• Biologists add thousands of newly identified species to the list each year.

• Estimates of the total number of species range from 10 million to more than 100 million.

Grouping Species: The Basic Concept

• To make sense of nature, people tend to group diverse items according to similarities.

• A species is generally defined as a group of organisms that

• live in the same place and time and

• have the potential to interbreed with one another in nature to produce healthy offspring.

Grouping Species: The Basic Concept

• We may even sort groups into broader categories, such as

• rodents (which include squirrels) and

• insects (which include butterflies).

• Taxonomy, the branch of biology that names and classifies species, is the arrangement of species into a hierarchy of broader and broader groups.

The Three Domains of Life

• The three domains of life are

1. Bacteria,

2. Archaea, and

3. Eukarya.

• Bacteria and Archaea have prokaryotic cells.

• Eukarya have eukaryotic cells.

Figure 1.7

D O

M A

IN B

A C

T E

R IA

D O

M A

A R

C H

A E

Kingdom Plantae

Kingdom Fungi

Kingdom Animalia

Protists (multiple kingdoms)

D O

M A

IN E

U K

A R

Y A

Figure 1.7-1

D O

M A

IN B

A C

T E

R IA

D O

M A

IN A

R C

H A

E A

Figure 1.7-1a

Domain Bacteria

Figure 1.7-1b

Domain Archaea

Figure 1.7-2

DOMAIN EUKARYA

Kingdom Plantae Kingdom Animalia

Kingdom Fungi Protists (multiple kingdoms)

Figure 1.7-2a

Kingdom Plantae

Figure 1.7-2b

Kingdom Fungi

Figure 1.7-2c

Kingdom Animalia

Figure 1.7-2d

Protists (multiple kingdoms)

The Three Domains of Life

• The Domain Eukarya in turn includes three smaller divisions called kingdoms:

1. Kingdom Plantae,

2. Kingdom Fungi, and

3. Kingdom Animalia.

• Most members of the three kingdoms are multicellular.

The Three Domains of Life

• These three multicellular kingdoms are distinguished partly by how the organisms obtain food.

• Plants produce their own sugars and other foods by photosynthesis.

• Fungi are mostly decomposers, digesting dead organisms and organic wastes.

• Animals obtain food by ingesting (eating) and digesting other organisms.

The Three Domains of Life

• Those eukaryotes that do not fit into any of the three kingdoms fall into a catch-all group called the protists.

• Most protists are single-celled; they include microscopic organisms such as amoebas.

• But protists also include certain multicellular forms, such as seaweeds.

• Scientists are in the process of organizing protists into multiple kingdoms, although they do not yet agree on exactly how to do this.

Major Themes in Biology

• Five unifying themes will serve as touchstones throughout our investigation of biology.

Figure 1.8

Evolution Structure/ Function

Information Flow

Energy Transformations

Interconnections within Systems

MAJOR THEMES IN BIOLOGY

Figure 1.8-1

Evolution

Figure 1.8-2

Structure/Function

Figure 1.8-3

Information Flow

Figure 1.8-4

Energy Transformations

Figure 1.8-5

Interconnections within Systems

Evolution

• What do a tree, a mushroom, and a human have in common?

• At the cellular level, all life bears striking similarities.

• Despite the amazing diversity of life, there is also striking unity.

• What can account for this combination of unity and diversity in life?

• The scientific explanation is the biological process called evolution.

Evolution

• Evolution is

• the fundamental principle of life and

• the core theme that unifies all of biology.

• The theory of evolution by natural selection, first described by Charles Darwin more than 150 years ago, is the one idea that makes sense of everything we know about living organisms.

Evolution

• 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 that represents a relatively recent branch point on the tree of life.

Figure 1.9

Ancestral bear

Common ancestor of all modern bears

Common ancestor of polar bear

and brown bear

Giant panda bear

Spectacled bear

Sloth bear

Sun bear

American black bear

Asiatic black bear

Polar bear

Brown bear

Evolution

• Through an ancestor that lived much farther back in time,

• all bears are also related to squirrels, humans, and all other mammals and

• all have hair and milk-producing mammary glands.

The Darwinian View of Life

• The evolutionary view of life came into focus in 1859 when Charles Darwin published On the Origin of Species by Means of Natural Selection.

The Darwinian View of Life

• Darwin’s book developed two main points:

• Species living today descended from a succession of ancestral species in what Darwin called “descent with modification,” capturing the duality of life’s

1. unity (descent) and

2. diversity (modification).

• Natural selection is the mechanism for descent with modification.

Figure 1.10

Figure 1.10-1

Figure 1.10-2

The Darwinian View of Life

• In the struggle for existence, those individuals with heritable traits best suited to the local environment are more likely to survive and leave the greatest number of healthy offspring.

The Darwinian View of Life

• Therefore, these passed-down traits that enhance survival and reproductive success will be represented in greater numbers the next generation.

• It is this unequal reproductive success that Darwin called natural selection because the environment “selects” only certain heritable traits from those already existing.

• The product of natural selection is adaptation, the accumulation of variations in a population over time.

The Darwinian View of Life

• We now recognize many examples of natural selection in action.

• A classic example involves the finches (a kind of bird) of the Galápagos Islands.

The Darwinian View of Life

• Over two decades, researchers measured changes in beak size in a population of a species of ground finch that eats mostly small seeds.

• In dry years, when the preferred small seeds are in short supply, the birds must eat large seeds.

• Birds with larger, stronger beaks have a feeding advantage and greater reproductive success, and the average beak depth for the population increases.

The Darwinian View of Life

• During wet years, small seeds become more abundant.

• Smaller beaks are more efficient for eating the plentiful small seeds, and thus the average beak depth decreases.

• Such changes are measurable evidence of natural selection in action.

Figure 1.11

The Darwinian View of Life

• Antibiotic resistance in bacteria evolves in response to the overuse of antibiotics when dairy and cattle farmers add antibiotics to feed.

• The members of the bacteria population will, through random chance, vary in their susceptibility to the antibiotic.

• Once the environment changes by the addition of antibiotics,

• some bacteria will succumb quickly and die,

• while others will tend to survive.

The Darwinian View of Life

• Those bacteria that survive will multiply, producing offspring that will likely inherit the traits that enhance survival.

• Over many bacterial generations, feeding antibiotics to cows may promote the evolution of antibiotic-resistant bacteria that, if transferred to the human food supply, could cause infections that are not susceptible to standard drug treatments.

Figure 1.12

Bacterium with antibiotic resistance

Bacteria

Population with varied inherited traits

Antibiotic added

Reproduction of survivors

Many generations

Elimination of individuals with certain traits Increasing frequency of traits that enhance survival and reproductive success

Figure 1.12-1

Bacterium with antibiotic resistance

Bacteria

Population with varied inherited traits

Figure 1.12-2

Antibiotic added

Elimination of individuals with certain traits

Figure 1.12-3

Reproduction of survivors

Figure 1.12-4

Many generations

Increasing frequency of traits that enhance survival and reproductive success

Observing Artificial Selection

• Artificial selection is the purposeful breeding of domesticated plants and animals by humans.

• Humans have customized crop plants through many generations of artificial selection by selecting different parts of the plant to accentuate as food.

Observing Artificial Selection

• All the vegetables shown in Figure 1.13 have a common ancestor in one species of wild mustard (shown in the center of the figure).

Figure 1.13

Cabbage from end buds

Brussels sprouts from side buds

Kohlrabi

from stems

Kale from leaves

Broccoli from flowers and stems

Cauliflower from flower clusters

Wild mustard

Observing Artificial Selection

• The power of selective breeding is also apparent in our pets, which have been bred for looks and usefulness.

• For example, people in different cultures have customized hundreds of dog breeds as different as basset hounds and Saint Bernards, all descended from wolves.

Figure 1.14

Gray wolves

Artificial selection

Domesticated dogs

Figure 1.14-1

Gray wolves

Figure 1.14-2

Domesticated dogs

Structure/Function: The Relationship of Structure to Function

• Within biological systems, structure (the shape of something) and function (what it does) are often related, with each providing insight into the other.

Structure/Function: The Relationship of Structure to Function

• The correlation of structure and function can be seen at every level of biological organization.

• Consider your lungs, which function to exchange gases with the environment:

• oxygen (O2) in,

• carbon dioxide (CO2) out.

Structure/Function: The Relationship of Structure to Function

• The structure of your lungs correlates with this function.

• Increasingly smaller branches end in millions of tiny sacs in which the gases cross from the air to your blood and vice versa.

• This structure provides a tremendous surface area over which a very high volume of air may pass.

Figure 1.15

Structure/Function: The Relationship of Structure to Function

• Cells, too, display a correlation of structure and function.

• As oxygen enters the blood in the lungs, it diffuses into red blood cells.

• The shape of red blood cells provides a large surface area over which oxygen can diffuse.

Figure 1. 16

Information Flow

• For life’s functions to proceed in an orderly manner, information must be

• stored,

• transmitted, and

• used.

Information Flow

• Every cell in your body was created when a previous cell transmitted information (in the form of DNA) to it.

• Even your very first cell, the zygote, or fertilized egg, contains information passed on from the previous generation.

Information Flow

• In this way, information flows from generation to generation, passed down encoded within molecules of DNA.

Information Flow

• All cells use DNA as the chemical material of genes, the units of inheritance that transmit information from parent to offspring.

• The language of life has an alphabet of just four letters.

• The chemical names of DNA’s four molecular building blocks are abbreviated as A, G, C, and T.

Information Flow

• A gene’s meaning to a cell is encoded in its specific sequence of these letters, just as the message of this sentence is encoded in its arrangement of the 26 letters of the English alphabet.

Figure 1.17

The four chemical building blocks of DNA

A DNA molecule

Information Flow

• The entire set of genetic information that an organism inherits is called its genome.

• The nucleus of each human cell contains a genome that is about 3 billion chemical letters long.

Information Flow

• At any given moment, your genes are producing thousands of different proteins that control your body’s processes.

• For example, the information in one of your genes translates to “Make insulin.”

• Insulin

• is produced by cells within the pancreas and

• is a chemical that helps regulate your body’s use of sugar as a fuel.

Information Flow

• Some people with diabetes regulate their sugar levels by injecting themselves with insulin produced by genetically engineered bacteria.

Figure 1.18

Energy Transformations: Pathways That Transform Energy and Matter

• Various cellular activities of life are work, such as movement, growth, and reproduction, and work requires energy.

• Life is made possible by

• the input of energy, primarily from the sun, and

• the transformation of energy from one form to another.

Energy Transformations: Pathways That Transform Energy and Matter

• Most ecosystems are solar powered.

• Plants and other photosynthetic organisms (“producers”)

• capture the energy that enters an ecosystem as sunlight and

• convert it, storing it as chemical bonds within sugars and other complex molecules.

Figure 1.19

Inflow

of light

energy

Outflow

of heat

energy

ECOSYSTEM

Consumers

(animals)

Chemical

energy

(food)

Decomposers

(in soil)

Producers

(plants and other

photosynthetic

organisms)

Cycling

nutrients

Energy Transformations: Pathways That Transform Energy and Matter

• Chemical energy is then passed through a series of “consumers” that break the bonds,

• releasing the stored energy and

• putting it to use.

Energy Transformations: Pathways That Transform Energy and Matter

• In the process of these energy conversions between and within organisms, some energy is converted to heat, which is then lost from the system.

• Thus, energy flows through an ecosystem,

• entering as light and

• exiting as heat.

Energy Transformations: Pathways That Transform Energy and Matter

• Every object in the universe, both living and nonliving, is composed of matter.

• In contrast to energy flowing through an ecosystem, matter is recycled within an ecosystem.

Energy Transformations: Pathways that Transform Energy and Matter

• Within all living cells, a vast network of interconnected chemical reactions (collectively referred to as metabolism) continually converts energy from one form to another as matter is recycled.

Interconnections within Biological Systems

• The study of life extends

• from the microscopic scale of the molecules and cells that make up organisms

• to the global scale of the entire living planet.

Figure 1.20-s1

Ecosystems

Communities

Populations

Organisms

Biosphere

Figure 1.20-s2

Ecosystems

Communities

Populations

Organisms

Biosphere

Organ

Systems

and

Organs

Tissues

Figure 1.20-s3

Ecosystems

Communities

Populations

Organisms

Biosphere

Organ

Systems

and

Organs

Tissues

78 Cells

9 Organelles

Nucleus

Atom

10 Molecules and Atoms

Figure 1.20-1

1 Biosphere

Figure 1.20-2

2 Ecosystems

3 Communities

Figure 1.20-3

4 Populations

5 Organisms

Figure 1.20-4

Organ Systems and Organs6

Figure 1.20-5

Tissues7

Figure 1.20-6

Cells

Organelles

Nucleus

Figure 1.20-7

10 Molecules and Atoms

Atom

Interconnections within Biological Systems

• The biosphere consists of

• all the environments on Earth that support life, including soil, oceans, lakes, and other bodies of water, and the lower atmosphere.

• At the other extreme of biological size and complexity are microscopic molecules such as DNA, the chemical responsible for inheritance.

Interconnections within Biological Systems

• At each new level, novel properties emerge that are absent from the preceding one.

• These emergent properties are due to the specific arrangement and interactions of parts in an increasingly complex system.

• Such properties are called emergent because they emerge as complexity increases.

Interconnections within Biological Systems

• The global climate

• is another example of interconnectedness within biological systems and

• operates on a much larger scale.

• Throughout our study of life, we will see countless interconnections that operate at and between every level of the biological hierarchy.

Interconnections within Biological Systems

• Biologists are investigating life at its many levels,

• from the interactions within the biosphere

• to the molecular machinery within cells.

Figure 1.UN01

Observation Question Hypothesis Prediction Experiment

Revise and repeat

Figure 1.UN02

Order Regulation Growth and

development

Energy processing

Response to

the environment Reproduction Evolution

Figure 1.UN03

Prokaryotes Eukaryotes

Domain Bacteria

Domain Archaea

Plantae Fungi Animalia

Three kingdoms

Domain Eukarya

Protists

(all other

eukaryotes)

Life

Figure 1.UN04

MAJOR THEMES IN BIOLOGY

Evolution Structure/

Function Information

Flow

Energy

Transformations

Interconnections

within Systems

Figure 1.UN05

Heart attack

patients

Non–heart-attack

patients

Data from: P. M. Clifton et al., Trans fatty acids in adipose tissue

and the food supply are associated with myocardial infarction.

Journal of Nutrition 134: 874–879 (2004).

T ra

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i n

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ip o

s e t

is s

u e

(g t

ra n

s f

a ts

p e r

1 0 0 g

t o

ta l

fa t)

2.0

1.5

1.0

0.5

1.77

1.48

Which of the topics in this module did you find most relevant to your everyday life?

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