1. Biology: Exploring Life
Chapter 1
Biology: Exploring Life
Lecture by Richard L. Myers

2. THEMES IN THE STUDY OF BIOLOGY
Copyright © 2009 Pearson Education, Inc.

3. 1.1 In life’s hierarchy of organization, new properties emerge at each level
Life’s levels of organization define the scope of biology
Life emerges through organization of various levels
With addition of each new level, novel properties emerge—called emergent properties
During the study of biology, life should be considered from the molecular to the global level. An understanding of emergent properties allows one to appreciate the complexity and difficulty of understanding life as well as to appreciate life’s close association with the entire planet. Although emergent properties help explain the diversity of life, examples of emergent properties are not limited to life. Graphite and diamonds are both composed of carbon, but the carbons within them are arranged differently. The result is emergent properties that make the two very different.
Student Misconceptions and Concerns
1. Many students enter our courses with a limited appreciation of the diversity of life. Ask any group of freshmen at the start of the semester to write down the first type of animal that comes to mind, and the most frequent response is a mammal. As the diversity of life is explored, the common heritage of biological organization can be less, and not more, apparent. The diverse forms, habits, and ecological interactions overwhelm our senses with striking distinctions. Emphasizing the diversity as well as the unifying aspects of life is necessary for a greater understanding of the rich evolutionary history of life on Earth.
2. We live in a world that is largely understood by what we can distinguish and identify with our naked senses. However, the diversity of life and the levels of biological organization extend well below the physical scale of our lives. For many students, appreciating the diversity of the microscopic world is abstract, nearly on par with an understanding of the workings of atoms and molecules. The ability to examine the microscopic details of the world of our students (the surface of potato chips, the structure of table salt and sugar, the details of a blade of grass) can be an important sensory extension that prepares the mind for greater comprehension of these minute biological details.
Teaching Tips
1. Consider asking students to bring to class a page or two of some article about biology that appeared in the media in the last month. Alternatively, you could have each student a Web address of a recent biology-related news event to you. You might even have them relevant articles to you for each of the main topics you address throughout the semester.
2. The scientific organization Sigma Xi offers a free summary of the major science news articles appearing each weekday in major U.S. news media. The first paragraph or so of each article is included in the with a hyperlink to the rest of the article. The diverse topics are an excellent way to learn of general scientific announcements and reports. Typically, 5–10 articles are cited in each . To sign up for this free service, go to
3. For a chance to add a little math to the biological levels of organization, consider calculating the general scale differences between each level of biological organization. For example, are cells generally 5, 10, 50, or 100 times larger than organelles? Are organelles generally 5, 10, 50, or 100 times larger than macromolecules? For some levels of organization, such as ecosystems, communities, and populations, size/scale differences are perhaps less relevant and more problematic to consider. However, at the smaller levels, the sense of scale might enhance an appreciation for levels of biological organization.
4. The U.S. Census Bureau maintains updated population clocks that estimate the U.S. and world populations on its website at If students have an accurate general idea of the population of the United States, statistics about the number of people affected with a disease or disaster become more significant. For example, the current population of the United States is approximately 305 million (2009). It is currently estimated that about one million people in the United States are infected with HIV. The number of people infected with HIV is impressive and concerning, but not perhaps as meaningful as realizing that the number of people infected represents one out of every 305 people in the United States. Although the infected people are not evenly distributed among geographic and ethnic groups, if you apply this generality to the enrollments in your classes, the students might better appreciate the tremendous impact of the infection.
Copyright © 2009 Pearson Education, Inc.

4. Figure 1.1 Life’s hierarchy of organization.
Biosphere
Ecosystem
Florida coast
Community
All organisms on
the Florida coast
Population
Group of brown
pelicans
Organism
Brown pelican
Spinal cord
Organ system
Nervous system
Figure 1.1 Life’s hierarchy of organization.
Brain
Nerve
Organ
Brain
Tissue
Nervous tissue
Cell
Nerve cell
Nucleus
Atom
Organelle
Nucleus
Molecule
DNA

5. Biosphere Ecosystem Florida coast Community All organisms on
the Florida coast
Figure 1.1 Life’s hierarchy of organization.
Population
Group of brown
pelicans
Organism
Brown pelican

6. Organism Brown pelican Spinal cord Organ system Nervous system Brain
Nerve
Tissue
Nervous tissue
Atom
Figure 1.1 Life’s hierarchy of organization.
Cell
Nerve cell
Nucleus
Organelle
Nucleus
Molecule
DNA

7. 1.1 In life’s hierarchy of organization, new properties emerge at each level
The upper tier is a global perspective of life
Biosphere-
Ecosystem—
Community—
Population—
Student Misconceptions and Concerns
1. Many students enter our courses with a limited appreciation of the diversity of life. Ask any group of freshmen at the start of the semester to write down the first type of animal that comes to mind, and the most frequent response is a mammal. As the diversity of life is explored, the common heritage of biological organization can be less, and not more, apparent. The diverse forms, habits, and ecological interactions overwhelm our senses with striking distinctions. Emphasizing the diversity as well as the unifying aspects of life is necessary for a greater understanding of the rich evolutionary history of life on Earth.
2. We live in a world that is largely understood by what we can distinguish and identify with our naked senses. However, the diversity of life and the levels of biological organization extend well below the physical scale of our lives. For many students, appreciating the diversity of the microscopic world is abstract, nearly on par with an understanding of the workings of atoms and molecules. The ability to examine the microscopic details of the world of our students (the surface of potato chips, the structure of table salt and sugar, the details of a blade of grass) can be an important sensory extension that prepares the mind for greater comprehension of these minute biological details.
Teaching Tips
1. Consider asking students to bring to class a page or two of some article about biology that appeared in the media in the last month. Alternatively, you could have each student a Web address of a recent biology-related news event to you. You might even have them relevant articles to you for each of the main topics you address throughout the semester.
2. The scientific organization Sigma Xi offers a free summary of the major science news articles appearing each weekday in major U.S. news media. The first paragraph or so of each article is included in the with a hyperlink to the rest of the article. The diverse topics are an excellent way to learn of general scientific announcements and reports. Typically, 5–10 articles are cited in each . To sign up for this free service, go to
3. For a chance to add a little math to the biological levels of organization, consider calculating the general scale differences between each level of biological organization. For example, are cells generally 5, 10, 50, or 100 times larger than organelles? Are organelles generally 5, 10, 50, or 100 times larger than macromolecules? For some levels of organization, such as ecosystems, communities, and populations, size/scale differences are perhaps less relevant and more problematic to consider. However, at the smaller levels, the sense of scale might enhance an appreciation for levels of biological organization.
4. The U.S. Census Bureau maintains updated population clocks that estimate the U.S. and world populations on its website at If students have an accurate general idea of the population of the United States, statistics about the number of people affected with a disease or disaster become more significant. For example, the current population of the United States is approximately 305 million (2009). It is currently estimated that about one million people in the United States are infected with HIV. The number of people infected with HIV is impressive and concerning, but not perhaps as meaningful as realizing that the number of people infected represents one out of every 305 people in the United States. Although the infected people are not evenly distributed among geographic and ethnic groups, if you apply this generality to the enrollments in your classes, the students might better appreciate the tremendous impact of the infection.
Copyright © 2009 Pearson Education, Inc.

8. 1.1 In life’s hierarchy of organization, new properties emerge at each level
The middle tier is characterized by the organism, an individual living thing, which is composed of
Organ systems—
Organs—
Tissues—
Many organisms, such as protists, algae, and bacteria, are composed of microscopic individuals that exist as single cells.
Student Misconceptions and Concerns
1. Many students enter our courses with a limited appreciation of the diversity of life. Ask any group of freshmen at the start of the semester to write down the first type of animal that comes to mind, and the most frequent response is a mammal. As the diversity of life is explored, the common heritage of biological organization can be less, and not more, apparent. The diverse forms, habits, and ecological interactions overwhelm our senses with striking distinctions. Emphasizing the diversity as well as the unifying aspects of life is necessary for a greater understanding of the rich evolutionary history of life on Earth.
2. We live in a world that is largely understood by what we can distinguish and identify with our naked senses. However, the diversity of life and the levels of biological organization extend well below the physical scale of our lives. For many students, appreciating the diversity of the microscopic world is abstract, nearly on par with an understanding of the workings of atoms and molecules. The ability to examine the microscopic details of the world of our students (the surface of potato chips, the structure of table salt and sugar, the details of a blade of grass) can be an important sensory extension that prepares the mind for greater comprehension of these minute biological details.
Teaching Tips
1. Consider asking students to bring to class a page or two of some article about biology that appeared in the media in the last month. Alternatively, you could have each student a Web address of a recent biology-related news event to you. You might even have them relevant articles to you for each of the main topics you address throughout the semester.
2. The scientific organization Sigma Xi offers a free summary of the major science news articles appearing each weekday in major U.S. news media. The first paragraph or so of each article is included in the with a hyperlink to the rest of the article. The diverse topics are an excellent way to learn of general scientific announcements and reports. Typically, 5–10 articles are cited in each . To sign up for this free service, go to
3. For a chance to add a little math to the biological levels of organization, consider calculating the general scale differences between each level of biological organization. For example, are cells generally 5, 10, 50, or 100 times larger than organelles? Are organelles generally 5, 10, 50, or 100 times larger than macromolecules? For some levels of organization, such as ecosystems, communities, and populations, size/scale differences are perhaps less relevant and more problematic to consider. However, at the smaller levels, the sense of scale might enhance an appreciation for levels of biological organization.
4. The U.S. Census Bureau maintains updated population clocks that estimate the U.S. and world populations on its website at If students have an accurate general idea of the population of the United States, statistics about the number of people affected with a disease or disaster become more significant. For example, the current population of the United States is approximately 305 million (2009). It is currently estimated that about one million people in the United States are infected with HIV. The number of people infected with HIV is impressive and concerning, but not perhaps as meaningful as realizing that the number of people infected represents one out of every 305 people in the United States. Although the infected people are not evenly distributed among geographic and ethnic groups, if you apply this generality to the enrollments in your classes, the students might better appreciate the tremendous impact of the infection.
Copyright © 2009 Pearson Education, Inc.

9. 1.1 In life’s hierarchy of organization, new properties emerge at each level
Life emerges at the level of the cell, the lower tier, which is composed of
Molecules—
Organelles—
Cells—
A study of reductionism could be introduced at this point. Reductionism is the reduction of complex systems, such as an animal, to simpler components that are easier to study.
Student Misconceptions and Concerns
1. Many students enter our courses with a limited appreciation of the diversity of life. Ask any group of freshmen at the start of the semester to write down the first type of animal that comes to mind, and the most frequent response is a mammal. As the diversity of life is explored, the common heritage of biological organization can be less, and not more, apparent. The diverse forms, habits, and ecological interactions overwhelm our senses with striking distinctions. Emphasizing the diversity as well as the unifying aspects of life is necessary for a greater understanding of the rich evolutionary history of life on Earth.
2. We live in a world that is largely understood by what we can distinguish and identify with our naked senses. However, the diversity of life and the levels of biological organization extend well below the physical scale of our lives. For many students, appreciating the diversity of the microscopic world is abstract, nearly on par with an understanding of the workings of atoms and molecules. The ability to examine the microscopic details of the world of our students (the surface of potato chips, the structure of table salt and sugar, the details of a blade of grass) can be an important sensory extension that prepares the mind for greater comprehension of these minute biological details.
Teaching Tips
1. Consider asking students to bring to class a page or two of some article about biology that appeared in the media in the last month. Alternatively, you could have each student a Web address of a recent biology-related news event to you. You might even have them relevant articles to you for each of the main topics you address throughout the semester.
2. The scientific organization Sigma Xi offers a free summary of the major science news articles appearing each weekday in major U.S. news media. The first paragraph or so of each article is included in the with a hyperlink to the rest of the article. The diverse topics are an excellent way to learn of general scientific announcements and reports. Typically, 5–10 articles are cited in each . To sign up for this free service, go to
3. For a chance to add a little math to the biological levels of organization, consider calculating the general scale differences between each level of biological organization. For example, are cells generally 5, 10, 50, or 100 times larger than organelles? Are organelles generally 5, 10, 50, or 100 times larger than macromolecules? For some levels of organization, such as ecosystems, communities, and populations, size/scale differences are perhaps less relevant and more problematic to consider. However, at the smaller levels, the sense of scale might enhance an appreciation for levels of biological organization.
4. The U.S. Census Bureau maintains updated population clocks that estimate the U.S. and world populations on its website at If students have an accurate general idea of the population of the United States, statistics about the number of people affected with a disease or disaster become more significant. For example, the current population of the United States is approximately 305 million (2009). It is currently estimated that about one million people in the United States are infected with HIV. The number of people infected with HIV is impressive and concerning, but not perhaps as meaningful as realizing that the number of people infected represents one out of every 305 people in the United States. Although the infected people are not evenly distributed among geographic and ethnic groups, if you apply this generality to the enrollments in your classes, the students might better appreciate the tremendous impact of the infection.
Copyright © 2009 Pearson Education, Inc.

10. 1.2 Living organisms interact with their environments, exchanging matter and energy
Life requires interactions between living and nonliving components
The nonliving components are chemical nutrients required for life
The nonliving components are recycled and used over and over again. Carbon dioxide, oxygen, water, and various minerals are examples of components cycled within an ecosystem.
Student Misconceptions and Concerns
1. Many students enter our courses with a limited appreciation of the diversity of life. Ask any group of freshmen at the start of the semester to write down the first type of animal that comes to mind, and the most frequent response is a mammal. As the diversity of life is explored, the common heritage of biological organization can be less, and not more, apparent. The diverse forms, habits, and ecological interactions overwhelm our senses with striking distinctions. Emphasizing the diversity as well as the unifying aspects of life is necessary for a greater understanding of the rich evolutionary history of life on Earth.
2. We live in a world that is largely understood by what we can distinguish and identify with our naked senses. However, the diversity of life and the levels of biological organization extend well below the physical scale of our lives. For many students, appreciating the diversity of the microscopic world is abstract, nearly on par with an understanding of the workings of atoms and molecules. The ability to examine the microscopic details of the world of our students (the surface of potato chips, the structure of table salt and sugar, the details of a blade of grass) can be an important sensory extension that prepares the mind for greater comprehension of these minute biological details.
Teaching Tips
1. Consider asking students to bring to class a page or two of some article about biology that appeared in the media in the last month. Alternatively, you could have each student a Web address of a recent biology-related news event to you. You might even have them relevant articles to you for each of the main topics you address throughout the semester.
2. The scientific organization Sigma Xi offers a free summary of the major science news articles appearing each weekday in major U.S. news media. The first paragraph or so of each article is included in the with a hyperlink to the rest of the article. The diverse topics are an excellent way to learn of general scientific announcements and reports. Typically, 5–10 articles are cited in each . To sign up for this free service, go to
3. Help the class think through the diverse interactions between an organism and its environment. In class, select an organism and have the class develop a list of environmental components that interact with the organism. Items in this list will likely fall into living and nonliving categories.
Copyright © 2009 Pearson Education, Inc.

11. 1.2 Living organisms interact with their environments, exchanging matter and energy
To be successful, an ecosystem must accomplish two things:
The importance of plants and other photosynthetic organisms to ecosystem dynamics cannot be overstated.
Student Misconceptions and Concerns
1. Many students enter our courses with a limited appreciation of the diversity of life. Ask any group of freshmen at the start of the semester to write down the first type of animal that comes to mind, and the most frequent response is a mammal. As the diversity of life is explored, the common heritage of biological organization can be less, and not more, apparent. The diverse forms, habits, and ecological interactions overwhelm our senses with striking distinctions. Emphasizing the diversity as well as the unifying aspects of life is necessary for a greater understanding of the rich evolutionary history of life on Earth.
2. We live in a world that is largely understood by what we can distinguish and identify with our naked senses. However, the diversity of life and the levels of biological organization extend well below the physical scale of our lives. For many students, appreciating the diversity of the microscopic world is abstract, nearly on par with an understanding of the workings of atoms and molecules. The ability to examine the microscopic details of the world of our students (the surface of potato chips, the structure of table salt and sugar, the details of a blade of grass) can be an important sensory extension that prepares the mind for greater comprehension of these minute biological details.
Teaching Tips
1. Consider asking students to bring to class a page or two of some article about biology that appeared in the media in the last month. Alternatively, you could have each student a Web address of a recent biology-related news event to you. You might even have them relevant articles to you for each of the main topics you address throughout the semester.
2. The scientific organization Sigma Xi offers a free summary of the major science news articles appearing each weekday in major U.S. news media. The first paragraph or so of each article is included in the with a hyperlink to the rest of the article. The diverse topics are an excellent way to learn of general scientific announcements and reports. Typically, 5–10 articles are cited in each . To sign up for this free service, go to
3. Help the class think through the diverse interactions between an organism and its environment. In class, select an organism and have the class develop a list of environmental components that interact with the organism. Items in this list will likely fall into living and nonliving categories.
Copyright © 2009 Pearson Education, Inc.

12. Ecosystem Sunlight Cycling of chemical nutrients Heat Heat Producers
(such as plants)
Cycling of
chemical
nutrients
Heat
Chemical energy
Consumers
(such as animals)
Figure 1.2 The cycling of nutrients and flow of energy in an ecosystem.
Heat

13. 1.3 Cells are the structural and functional units of life
Form generally fits function
By studying a biological structure, you determine what it does and how it works
Life emerges from interactions of structures
Combinations of structures (components) provide organization called a system
Student Misconceptions and Concerns
1. Many students enter our courses with a limited appreciation of the diversity of life. Ask any group of freshmen at the start of the semester to write down the first type of animal that comes to mind, and the most frequent response is a mammal. As the diversity of life is explored, the common heritage of biological organization can be less, and not more, apparent. The diverse forms, habits, and ecological interactions overwhelm our senses with striking distinctions. Emphasizing the diversity as well as the unifying aspects of life is necessary for a greater understanding of the rich evolutionary history of life on Earth.
2. We live in a world that is largely understood by what we can distinguish and identify with our naked senses. However, the diversity of life and the levels of biological organization extend well below the physical scale of our lives. For many students, appreciating the diversity of the microscopic world is abstract, nearly on par with an understanding of the workings of atoms and molecules. The ability to examine the microscopic details of the world of our students (the surface of potato chips, the structure of table salt and sugar, the details of a blade of grass) can be an important sensory extension that prepares the mind for greater comprehension of these minute biological details.
Teaching Tips
1. Consider asking students to bring to class a page or two of some article about biology that appeared in the media in the last month. Alternatively, you could have each student a Web address of a recent biology-related news event to you. You might even have them relevant articles to you for each of the main topics you address throughout the semester.
2. The scientific organization Sigma Xi offers a free summary of the major science news articles appearing each weekday in major U.S. news media. The first paragraph or so of each article is included in the with a hyperlink to the rest of the article. The diverse topics are an excellent way to learn of general scientific announcements and reports. Typically, 5–10 articles are cited in each . To sign up for this free service, go to
3. Help the class think through the diverse interactions between an organism and its environment. In class, select an organism and have the class develop a list of environmental components that interact with the organism. Items in this list will likely fall into living and nonliving categories.
4. Here is a simple way to contrast the relative size of prokaryotic and eukaryotic cells. Mitochondria and chloroplasts are thought to have evolved by endosymbiosis (see Chapter 16). Thus, mitochondria and chloroplasts are about the size of bacteria, contained within a plant cell. A figure of a plant cell therefore provides an immediate comparison of these sizes, not side-by-side, but one inside the other!
5. Examples of biological form and function relationships are nearly endless. Those immediately apparent to your students will be easiest to comprehend. Have your students examine (in photos or in specimens) the teeth of various vertebrates. The diet of these animals is implied by the shape of the teeth (sharp teeth in carnivorous cats and blunted molars in a rat). Sliding your tongue over your teeth reveals our omnivorous history, with sharp canine teeth for slicing flesh and flat rear molars well-suited for grinding plant material.
Copyright © 2009 Pearson Education, Inc.

14. 1.3 Cells are the structural and functional units of life
Two distinct groups of cells exist
Prokaryotic cells
Eukaryotic cells
Regardless of the group studied, cells are enclosed by a membrane and use DNA as their genetic information.
Student Misconceptions and Concerns
1. Many students enter our courses with a limited appreciation of the diversity of life. Ask any group of freshmen at the start of the semester to write down the first type of animal that comes to mind, and the most frequent response is a mammal. As the diversity of life is explored, the common heritage of biological organization can be less, and not more, apparent. The diverse forms, habits, and ecological interactions overwhelm our senses with striking distinctions. Emphasizing the diversity as well as the unifying aspects of life is necessary for a greater understanding of the rich evolutionary history of life on Earth.
2. We live in a world that is largely understood by what we can distinguish and identify with our naked senses. However, the diversity of life and the levels of biological organization extend well below the physical scale of our lives. For many students, appreciating the diversity of the microscopic world is abstract, nearly on par with an understanding of the workings of atoms and molecules. The ability to examine the microscopic details of the world of our students (the surface of potato chips, the structure of table salt and sugar, the details of a blade of grass) can be an important sensory extension that prepares the mind for greater comprehension of these minute biological details.
Teaching Tips
1. Consider asking students to bring to class a page or two of some article about biology that appeared in the media in the last month. Alternatively, you could have each student a Web address of a recent biology-related news event to you. You might even have them relevant articles to you for each of the main topics you address throughout the semester.
2. The scientific organization Sigma Xi offers a free summary of the major science news articles appearing each weekday in major U.S. news media. The first paragraph or so of each article is included in the with a hyperlink to the rest of the article. The diverse topics are an excellent way to learn of general scientific announcements and reports. Typically, 5–10 articles are cited in each . To sign up for this free service, go to
3. Help the class think through the diverse interactions between an organism and its environment. In class, select an organism and have the class develop a list of environmental components that interact with the organism. Items in this list will likely fall into living and nonliving categories.
4. Here is a simple way to contrast the relative size of prokaryotic and eukaryotic cells. Mitochondria and chloroplasts are thought to have evolved by endosymbiosis (see Chapter 16). Thus, mitochondria and chloroplasts are about the size of bacteria, contained within a plant cell. A figure of a plant cell therefore provides an immediate comparison of these sizes, not side-by-side, but one inside the other!
5. Examples of biological form and function relationships are nearly endless. Those immediately apparent to your students will be easiest to comprehend. Have your students examine (in photos or in specimens) the teeth of various vertebrates. The diet of these animals is implied by the shape of the teeth (sharp teeth in carnivorous cats and blunted molars in a rat). Sliding your tongue over your teeth reveals our omnivorous history, with sharp canine teeth for slicing flesh and flat rear molars well-suited for grinding plant material.
Copyright © 2009 Pearson Education, Inc.

15. Prokaryotic cell Eukaryotic cell DNA (no nucleus) Membrane Nucleus
Figure 1.3 Contrasting the size and complexity of prokaryotic and eukaryotic cells.
This figure indicates that the eukaryotic cell is subdivided into functional compartments (organelles) by membranes.
Nucleus
(contains DNA)
Organelles

16. EVOLUTION, THE CORE THEME OF BIOLOGY
Copyright © 2009 Pearson Education, Inc.

17. 1.4 The unity of life: All forms of life have common features
DNA is the genetic (hereditary) material of all cells
Teaching Tips
1. The authors make an analogy between the four bases used to form genes and the 26 letters of the English alphabet used to create words and sentences. One could also make an analogy between the four bases and trains composed of four different types of railroad cars (perhaps an engine, boxcar, tanker, and caboose). Imagine how many different types of trains one could make using just 100 rail cars of four different types. (The answer is 4100.)
2. The seven characteristics of life described in Module 1.4 can easily become another list to memorize. Exercises that require reflection and analysis of these significant traits can help to make this list more meaningful. Consider creating examples of each of these properties for students to analyze and identify.
Copyright © 2009 Pearson Education, Inc.

18. (b) Single strand of DNA
Nucleus
DNA
Nucleotide
Cell
Campbell, Neil, and Jane Reece, Biology, 8th ed., Figure 1.10 DNA: The genetic material; (a) DNA double helix, (b) Single strand of DNA.
(a) DNA double helix
(b) Single strand of DNA

19. 1.4 The unity of life: All forms of life have common features
All living things share common properties
Teaching Tips
1. The authors make an analogy between the four bases used to form genes and the 26 letters of the English alphabet used to create words and sentences. One could also make an analogy between the four bases and trains composed of four different types of railroad cars (perhaps an engine, boxcar, tanker, and caboose). Imagine how many different types of trains one could make using just 100 rail cars of four different types. (The answer is 4100.)
2. The seven characteristics of life described in Module 1.4 can easily become another list to memorize. Exercises that require reflection and analysis of these significant traits can help to make this list more meaningful. Consider creating examples of each of these properties for students to analyze and identify.
Copyright © 2009 Pearson Education, Inc.

20. 1.4 The unity of life: All forms of life have common features
These common properties separate life forms from Earth’s other forms. Viruses, for example, are very important infectious agents but, because they do not share all of the properties listed here, are not considered “living.” Not all viruses have DNA; some use RNA as their genetic information. Viruses cannot generate energy through metabolism, but rather depend upon host cells for their energy needs.
Teaching Tips
1. The authors make an analogy between the four bases used to form genes and the 26 letters of the English alphabet used to create words and sentences. One could also make an analogy between the four bases and trains composed of four different types of railroad cars (perhaps an engine, boxcar, tanker, and caboose). Imagine how many different types of trains one could make using just 100 rail cars of four different types. (The answer is 4100.)
2. The seven characteristics of life described in Module 1.4 can easily become another list to memorize. Exercises that require reflection and analysis of these significant traits can help to make this list more meaningful. Consider creating examples of each of these properties for students to analyze and identify.
Copyright © 2009 Pearson Education, Inc.

21. (3) Growth and development (4) Energy processing
(1) Order
(2) Regulation
(3) Growth and development
(4) Energy processing
Figure 1.4B Some important properties of life.
(5) Response to the environment
(6) Reproduction
(7) Evolutionary adaptation

22. 1.5 The diversity of life can be arranged into three domains
The three domains (groups) of life
Archaea live in unusual places, such as thermal vents in deep oceans, in hot springs and even in places where they are continually exposed to an extreme pH. Some scientists believe that these environments mimic early Earth and suggest that Archaea may be reminiscent of early forms of life.
You may want to give a brief definition of species, which is discussed in detail in Chapter 14.
Teaching Tips
1. An excellent introduction to the domains and kingdoms of life is presented at
Copyright © 2009 Pearson Education, Inc.

23. Domain Eukarya Domain Bacteria Domain Archaea
Bacteria (multiple kingdoms)
Protists (multiple kingdoms)
Kingdom Plantae
Domain Archaea
Figure 1.5B The three domains of life.
Archaea (multiple kingdoms)
Kingdom Fungi
Kingdom Animalia

24. 1.6 Evolution explains the unity and diversity of life
In 1859, Charles Darwin published On the Origin of Species by Means of Natural Selection
The book accomplished two things
Student Misconceptions and Concerns
1. Students often misunderstand the basic process of evolution and instead express a Lamarckian point of view. Organisms do not evolve structures deliberately or out of want or need, and individuals do not evolve. Evolution is a passive process in which the environment favors one or more variations of a trait that naturally exist within a population.
2. Students often believe that Charles Darwin was the first to suggest that life evolves; the early contributions by Greek philosophers and the work of Jean-Baptiste de Lamarck and others may be unappreciated. Consider emphasizing this earlier work in your introduction to Darwin’s contributions.
Teaching Tips
1. Many resources related to Charles Darwin are available on the Internet.
a. General evolution resources:
b. Texts of The Voyage of the Beagle, The Origin of Species (first and sixth editions), and The Descent of Man can be found at
c. Details about Charles Darwin’s home are located at
d. An extensive usenet newsgroup devoted to the discussion and debate of biological and physical origins is at
2. Many games model aspects of natural selection. Here is one that is appropriate for a laboratory exercise. Purchase several bags of dried grocery store beans of diverse sizes and colors. Large lima beans, small white beans, red beans, and black beans are all good options. Consider the beans food for the “predatory” students. To begin, randomly distribute (throw) 100 beans of each of four colors onto a green lawn. Allow individual students to collect beans over a set period, perhaps 2 minutes. Then count the total number of each color of bean collected. Assume that the beans remaining undetected (still in the lawn) reproduce by doubling in number. Calculate the number of beans of each color remaining in the field. For the next round, count out the number of each color to add to the lawn such that the new totals on the lawn will double the number of beans that students did not find in the first “generation”. Before each predatory episode, record the total number of each color of beans that have “survived” in the field. Then let your student predators search for another round (generation). Repeat the process for at least three or four generations. Note what colors of beans have been favored by the environment. Apply Darwin’s observations and inferences to this exercise. Ask students to speculate which colors might have been favored during another season of the year or in another location, such as a parking lot.
Copyright © 2009 Pearson Education, Inc.

25. 1.6 Evolution explains the unity and diversity of life
Natural selection was inferred by connecting two observations
Student Misconceptions and Concerns
1. Students often misunderstand the basic process of evolution and instead express a Lamarckian point of view. Organisms do not evolve structures deliberately or out of want or need, and individuals do not evolve. Evolution is a passive process in which the environment favors one or more variations of a trait that naturally exist within a population.
2. Students often believe that Charles Darwin was the first to suggest that life evolves; the early contributions by Greek philosophers and the work of Jean-Baptiste de Lamarck and others may be unappreciated. Consider emphasizing this earlier work in your introduction to Darwin’s contributions.
Teaching Tips
1. Many resources related to Charles Darwin are available on the Internet.
a. General evolution resources:
b. Texts of The Voyage of the Beagle, The Origin of Species (first and sixth editions), and The Descent of Man can be found at
c. Details about Charles Darwin’s home are located at
d. An extensive usenet newsgroup devoted to the discussion and debate of biological and physical origins is at
2. Many games model aspects of natural selection. Here is one that is appropriate for a laboratory exercise. Purchase several bags of dried grocery store beans of diverse sizes and colors. Large lima beans, small white beans, red beans, and black beans are all good options. Consider the beans food for the “predatory” students. To begin, randomly distribute (throw) 100 beans of each of four colors onto a green lawn. Allow individual students to collect beans over a set period, perhaps 2 minutes. Then count the total number of each color of bean collected. Assume that the beans remaining undetected (still in the lawn) reproduce by doubling in number. Calculate the number of beans of each color remaining in the field. For the next round, count out the number of each color to add to the lawn such that the new totals on the lawn will double the number of beans that students did not find in the first “generation”. Before each predatory episode, record the total number of each color of beans that have “survived” in the field. Then let your student predators search for another round (generation). Repeat the process for at least three or four generations. Note what colors of beans have been favored by the environment. Apply Darwin’s observations and inferences to this exercise. Ask students to speculate which colors might have been favored during another season of the year or in another location, such as a parking lot.
Copyright © 2009 Pearson Education, Inc.

26. 1.6 Evolution explains the unity and diversity of life
Natural selection is an editing mechanism
It results from exposure of heritable variations to environmental factors that favor some individuals over others
Student Misconceptions and Concerns
1. Students often misunderstand the basic process of evolution and instead express a Lamarckian point of view. Organisms do not evolve structures deliberately or out of want or need, and individuals do not evolve. Evolution is a passive process in which the environment favors one or more variations of a trait that naturally exist within a population.
2. Students often believe that Charles Darwin was the first to suggest that life evolves; the early contributions by Greek philosophers and the work of Jean-Baptiste de Lamarck and others may be unappreciated. Consider emphasizing this earlier work in your introduction to Darwin’s contributions.
Teaching Tips
1. Many resources related to Charles Darwin are available on the Internet.
a. General evolution resources:
b. Texts of The Voyage of the Beagle, The Origin of Species (first and sixth editions), and The Descent of Man can be found at
c. Details about Charles Darwin’s home are located at
d. An extensive usenet newsgroup devoted to the discussion and debate of biological and physical origins is at
2. Many games model aspects of natural selection. Here is one that is appropriate for a laboratory exercise. Purchase several bags of dried grocery store beans of diverse sizes and colors. Large lima beans, small white beans, red beans, and black beans are all good options. Consider the beans food for the “predatory” students. To begin, randomly distribute (throw) 100 beans of each of four colors onto a green lawn. Allow individual students to collect beans over a set period, perhaps 2 minutes. Then count the total number of each color of bean collected. Assume that the
beans remaining undetected (still in the lawn) reproduce by doubling in number. Calculate the number of beans of each color remaining in the field. For the next round, count out the number of each color to add to the lawn such that the new totals on the lawn will double the number of beans that students did not find in the first “generation”. Before each predatory episode, record the total number of each color of beans that have “survived” in the field. Then let your student predators search for another round (generation). Repeat the process for at least three or four generations. Note what colors of beans have been favored by the environment. Apply Darwin’s observations and inferences to this exercise. Ask students to speculate which colors might have been favored during another season of the year or in another location, such as a parking lot.
Copyright © 2009 Pearson Education, Inc.

27. Population with varied inherited traits1
Population with varied inherited traits 2
Elimination of individuals with certain traits
Figure 1.6B An example of natural selection in action. 3
Reproduction of survivors