© 2013 Pearson Education, Inc.Lectures by Edward J. Zalisko

PowerPoint ® Lectures forCampbell Essential Biology, Fifth Edition, andCampbell Essential Biology with Physiology, Fourth Edition

– Eric J. Simon, Jean L. Dickey, and Jane B. Reece

Chapter 1Chapter 1Introduction: Biology Today

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• 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.

THE SCOPE OF LIFE The Properties of Life

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Properties of Life:

1) Order

2) Regulation

3) Growth and delopment

4) Energy Processing

5) Respons to the Environment

6) Reproduction

7) Evolution

3 Properties of Life:

1) Order

– All living things exhibit complex but ordered organization

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Properties of Life:

2) Regulation

– The environment outside an organism may change drastically, but the organism can adjust its internal environment,

5 Properties of Life:

3) Growth and development

– Information carried by DNA controls the pattern of growth and development

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Properties of Life:

4) Energy processing

– Organisms take in energy and use it to perform all of life’s activities; they emit energy as heat

7 Properties of Life:

5) Response to the environment

– All organisms respond to environmental stimuli.

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Properties of Life:

6) Response to the environment

– Organisms reproduce their own kind

9 Properties of Life:

7) Evolution

– Reproduction underlies the capacity of populations to change (evolve) over time.

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• Biologists explore life at levels ranging from the biosphere to the molecules that make up cells.

Life at Its Many Levels

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• Biologists explore life at levels ranging from the biosphere to the molecules that make up cells.

Life at Its Many Levels

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

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

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• Biologists explore life at levels ranging from the biosphere to the molecules that make up cells.

Life at Its Many Levels

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

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• Biologists explore life at levels ranging from the biosphere to the molecules that make up cells.

Life at Its Many Levels

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

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• Biologists explore life at levels ranging from the biosphere to the molecules that make up cells.

Life at Its Many Levels

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

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• Biologists explore life at levels ranging from the biosphere to the molecules that make up cells.

Life at Its Many Levels

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

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• Biologists explore life at levels ranging from the biosphere to the molecules that make up cells.

Life at Its Many Levels

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

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• Biologists explore life at levels ranging from the biosphere to the molecules that make up cells.

Life at Its Many Levels

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

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• Biologists explore life at levels ranging from the biosphere to the molecules that make up cells.

Life at Its Many Levels

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

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• Biologists explore life at levels ranging from the biosphere to the molecules that make up cells.

Life at Its Many Levels

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

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• Biologists explore life at levels ranging from the biosphere to the molecules that make up cells.

Life at Its Many Levels

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

Nucleus

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• Biologists explore life at levels ranging from the biosphere to the molecules that make up cells.

Life at Its Many Levels

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

Atom

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Ecosystems

• 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 .

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23 Ecosystems

• 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.

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Figure 1.3

ECOSYSTEMInflowof lightenergy

Outflowof heatenergy

Producers(plants and otherphotosyntheticorganisms)

Chemicalenergy(food)

Cyclingof

nutrients

Consumers(animals)

Decomposers(in soil)

25 Cells and Their DNA

• 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.

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• 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.

Cells and Their DNA

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• 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.

Cells and Their DNA

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Figure 1.4

Nucleoidregion Nucleus

Organelles

Prokaryotic cell (bacterium)Smaller

Simpler structure

DNA concentrated innucleoid region, which isnot enclosed by membrane

Lacks most organelles

•••

•

••

•

•

Larger

More complexstructureNucleus enclosedby membrane

Contains many types of organelles

Eukaryotic cell

Col

oriz

ed T

EM

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• 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.

Cells and Their DNA

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Figure 1.5

A DNA molecule

The fourchemicalbuildingblocks of DNA

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• Genetic engineering has transformed the pharmaceutical industry and extended millions of lives.

Cells and Their DNA

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Figure 1.6 33

• 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.

Cells and Their DNA

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Life in Its Diverse Forms

• 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.

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35 Figure 1.7 36

Grouping Species: The Basic Concept

• 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.

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37 The Three Domains of Life

• The three domains of life are

– Bacteria ,

– Archaea , and

– Eukarya .

• Bacteria and Archaea have prokaryotic cells.

• Eukarya have eukaryotic cells.

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• Eukarya include

– Kingdom Plantae,

– Kingdom Fungi,

– Kingdom Animalia, and

– Protists (multiple kingdoms).

• Most plants, fungi, and animals are multicellular.

• Protists are generally single-celled.

The Three Domains of Life

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• 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.

The Three Domains of Life

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Figure 1.8

Protists (multiple kingdoms)

Kingdom Animalia

Kingdom Fungi

Kingdom Plantae

DO

MA

IN E

UK

AR

YADO

MA

IN

AR

CH

AE

AD

OM

AIN

B

AC

TE

RIA

41 Unity in the Diversity of Life

• 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.

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- 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.

43 Unity in the Diversity of Life

• 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.

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