Chapter 5 49
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BIOLOGICAL CONCEPTS
Chapter Outline
BUILDING BLOCKS OF LIFE
Carbohydrates
Sugars
CELLS
Types of Cells
Organelles
Nucleus and Ribosomes
Organelles Involved in Synthesis,
Cellular Division in Prokaryotes
Cellular Division in Eukaryotes
Levels of Organization
EVOLUTION AND NATURAL
SELECTION
Darwin and the Theory for Evolution
Voyage of Discovery
Formulating a Theory for Evolution
Evolution of New Species
Typological Definition of Species
Modern Species Definition
Process of Speciation
CLASSIFICATION: BRINGING ORDER TO
ARE YOU STILL WONDERING?
QUESTIONS FOR REVIEW
SUGGESTIONS FOR FURTHER READING
Chapter Objectives
• Describe the structure and function of the four macromolecules.
• Compare and contrast prokaryotic and eukaryotic cells.
• Identify the function of the various organelles within a eukaryotic cell.
Key Terms
macromolecules
carbohydrates
monosaccharides
glucose
disaccharides
chitin
lipids
triglyceride
phospholipids
steroids
proteins
amino acids
polypeptides
ribosomal RNA (rRNA)
transfer RNA (tRNA)
cells
cell membrane
cell wall
nucleus
chromosomes
nucleolus
endoplasmic reticulum
(ER)
rough endoplasmic
reticulum (RER)
smooth endoplasmic
thylakoids
stroma
carbon fixation
binary fission
mitosis
genetics
molecular biology
modern synthetic theory
of evolution
alleles
asexual reproduction
sexual reproduction
haploid number
species (modern
definition)
morphology
hybrids
speciation
allopatric speciation
fungi
plants
animals
Chapter Summary
1. Four main groups of large molecules are necessary for life: carbohydrates, lipids,
proteins, and nucleic acids.
2. All living things are composed of cells. Prokaryotic cells lack a nucleus and
membrane-bound organelles. Eukaryotic cells have a nucleus and many membrane-
3. Charles Darwin introduced the theory of evolution by natural selection in 1859 in his
book On the Origin of Species by Means of Natural Selection. His theory suggests that
4. Although the genetic mechanisms that govern inheritance play a significant role in
evolution, they were unknown during Darwin’s time. The modern synthetic theory
5. Today, a species is defined as one or more populations of potentially interbreeding
organisms that are reproductively isolated from other such groups. New species
52 Biological Concepts
6. Biologists throughout the world use a common system for naming organisms. The
system, known as binomial nomenclature, uses two words—a genus and species
epithet—to identify a given species. The science of taxonomy deals with classifying
Chapter Outline
I. Building Blocks of Life
A. Carbohydrates.
1. Sugars.
2. Polysaccharides.
1. DNA (deoxyribonucleic acid).
a. Nitrogenous bases: adenine, guanine, cytosine, and thymine.
b. Genes.
c. Transfer RNA (t-RNA).
II. Cells: Basic Units of Life
A. Types of cells.
1. Prokaryotic cells.
2. Eukaryotic cells.
B. Organelles.
1. Nucleus.
4. Golgi apparatus.
5. Lysosome.
6. Vacuole.
C. Energy transfer in cells.
1. Photosynthesis.
a. Thylakoids.
E. Levels of organization: arranged from simplest to most complex (refer to Figure 5-12).
1. Cell.
2. Tissue.
III. Evolution and Natural Selection
A. Evolution: change in gene frequency over time.
B. Darwin and the theory for evolution.
1. Voyage of the HMS Beagle (1831–1836).
C. Theory of evolution by natural selection.
1. Artificial selection.
2. Natural selection: “survival of the fittest.”
a. Organisms produce more offspring than will survive to reproductive age.
b. There is considerable variation in natural populations; many of the variations
are heritable.
D. Genes and natural selection.
1. Genetics: the study of inheritance.
2. Modern synthetic theory of evolution.
3. Alleles.
4. Role of reproduction (refer to Figure 5–16).
a. Asexual reproduction.
i. Common in stable environments, where it is not necessary to invest
energy in looking for a mate.
ii. Beneficial to populations; can rapidly increase asexually (bacteria).
54 Biological Concepts
g. In many life cycles—such as plant, protist, and fungi—there is an alternation
between haploid and diploid forms; in animals, the haploid phase is reduced
IV. Evolution of New Species
A. Typological species definition.
1. Morphology.
2. Sexual dimorphism.
3. Species.
B. Modern species definition.
1. Reproductive isolation.
a. Prevent the act of breeding.
i. Habitat isolation.
ii. Anatomical isolation.
C. Process of speciation.
1. Allopatric speciation.
V. Classification: Bringing Order to Diversity
A. Linnaeus and the binomial system of naming.
1. Binomial nomenclature: system of naming organisms using two words, proposed by
B. Taxonomy: science of classification.
1. Until the 1960s, biologists considered everything to be either a plant or an animal.
2. Modern classification.
a. Three domains, largest taxonomic grouping.
i. Domain Archaea (primitive bacteria).
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ii. Phylogenetic tree.
iii. Phenetics.
iv. Cladistics.
v. Cladogram.
Suggestions for Presenting the Material
1. Assign a section from Darwin’s Origin of the Species and ask students to summarize
Classroom Discussion Ideas
1. What are the differences between prokaryotic and eukaryotic cells? Why is it
important to know about how cells work when studying marine biology?
2. Discuss how natural selection explains the way in which creatures diversified. How
does this relate to ecological niches?
3. How influential is reproduction on the process of evolution and speciation?
Videos, Animations, and Websites
Videos
The Habitable Planet Unit 9 — Biodiversity Decline. (video course)
Referenced in the chapters of the textbook, this series of videos covers a wide array of
Nova—Evolution: Extinction! (PBS Series)
PBS Video Library—Evolution.
Series of short videos discussing different aspects of evolution, its history, and
Animations
Evolution: Deep Time Interactive.
56 Biological Concepts
Websites
University of California Museum of Paleontology, Evolution Exhibit.
Tree of Life.
Evolving Planet.
Archived from the Field Museum in Chicago—a great overview of geologic time,
National Evolutionary Synthesis Center.
Good resource for current information on evolution in the news and examples of
Biological Diversity and Classification.
Good introduction to naming and taxonomy.
Suggested Answers to End of Chapter Questions
Multiple Choice
1. c. synthesize proteins
Matching
1. c.
2. a.
3. e.
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Short Answer
1. How can you distinguish between flagella and cilia?
2. How can you distinguish prokaryotic cells from eukaryotic cells?
Prokaryotic cells lack a membrane-bound nucleus and membrane-bound
3. What are the four points of Darwin’s theory of evolution by natural selection?
Darwin’s theory of evolution by natural selection contains four basic premises:
1. All organisms produce more offspring than will survive to reproduce.
4. What are the higher categories in modern classification?
The categories in modern classification, from most general to most specific, are:
5. Describe how new species are formed.
New species are formed when a population becomes reproductively isolated,
6. Describe how populations can become reproductively isolated.
Reproductive isolation can be physical due to geographic barriers such as a river,
58 Biological Concepts
7. Describe the characteristics of organisms in each of the three domains.
The members of the domains Archaea and Bacteria are prokaryotic organisms, but
8. Compare asexual and sexual reproduction.
Sexual reproduction produces offspring that have new combinations of genetic
9. Why does it make more sense not to place protists into one kingdom?
All members of the kingdom Protista have an independent unicellular phase at
10. How does the phenetic approach to taxonomy differ from the cladistic approach?
Phenetics is the classification of organisms based on shared characteristics, in
Thinking Critically
1. While studying plankton samples, a friend asks you how you can distinguish
protozoans from small animals such as crustaceans. What would you answer?
2. While on a field trip, you collect two snails that look very similar. How would you
determine if they are the same or different species using the methods available in
1858? How would you determine it using the methods available today?
Using phenetic classification (taxonomic classification scheme used in 1858), you
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3. While working in the field you collect several similar specimens of marine fishes
from populations in two different localities. What experiments would you perform
to determine if these fishes are the same or different species? What results might you
expect from these experiments, and what might the results prove?
Molecular studies would characterize the genome of each population of marine
Suggested InfoTrac® Articles
“On the Origin of a Theory.” Conniff, R. Smithsonian, (2008).