Bio 2 ch1 Notes

© 2012 Pearson Education, Inc. Lecture by Edward J. Zalisko
PowerPoint Lectures for
Campbell Biology: Concepts & Connections, Seventh Edition
Reece, Taylor, Simon, and Dickey
Biology: Exploring Life

Chapter 1: Big Ideas
Themes in the Study
of Biology
The Process
of Science
Biology and
Everyday Life
Evolution, the Core
Theme of Biology

 Biology is the scientific study of life.
 Properties of life include
1. Order—the highly ordered structure that typifies life,
2. Reproduction—the ability of organisms to reproduce
their own kind,
3. Growth and development—consistent growth and
development controlled by inherited DNA,
4. Energy processing—the use of chemical energy to power
an organism’s activities and chemical reactions,
© 2012 Pearson Education, Inc.

5. Response to the environment—an ability to
respond to environmental stimuli,
6. Regulation—an ability to control an organism’s
internal environment within limits that sustain
life, and
7. Evolutionary adaptation—adaptations evolve over
many generations as individuals with traits best
suited to their environments have greater
reproductive success and pass their traits to
offspring.

Biosphere
Madagascar
Ecosystem:
Forest in
Madagascar
Community:
All organisms in
the forest
Population:
Group of ring-tailed
lemurs
Organism:
Ring-tailed lemur

Organism:
Ring-tailed lemur
Organ system:
Nervous system
Organ:
Brain
Tissue:
Nervous tissue
Nerve
Spinal
cord
Brain
Organelle:
Nucleus
Cell:
Nerve cell
Nucleus
Atom
Molecule:
DNA

 Cells are the level at which the properties of life
emerge.
 A cell can
 regulate its internal environment,
 take in and use energy,
 respond to its environment,
 develop and maintain its complex organization, and
 give rise to new cells.

 All cells
 are enclosed by a membrane that regulates the passage
of materials between the cell and its surroundings and
 use DNA as their genetic information.

 There are two basic types of cells.
1. Prokaryotic cells
 were the first to evolve,
 are simpler, and
 are usually smaller than eukaryotic cells.
 bacteria
2. Eukaryotic cells
 contain membrane-enclosed organelles, including a nucleus
containing DNA, and
 are found in plants, animals, and fungi.

Eukaryotic cell
Membrane
Prokaryotic
cell
DNA
(no nucleus)
Organelles
Nucleus
(membrane-
enclosed)
DNA (throughout
nucleus)

 Cells illustrate another theme in biology: the
correlation of structure and function.
 Structure is related to function at all levels of
biological organization.

 Living organisms interact with their
environments, which include other organisms and
physical (non-living) factors.
 In most ecosystems
 plants are the producers that provide the food,
 consumers eat plants and other animals, and
 decomposers act as recyclers, changing complex matter
into simpler mineral nutrients.

Figure 1.4
Ecosystem
Sunlight
CO2
Heat
Chemical energy
(food)
Producers
(such as
plants)
Water and minerals
taken up by tree roots
Cycling of
chemical nutrients
Decomposers
(in soil)
Consumers
(such as
animals)
CO2
O2O2

 All cells have DNA, the chemical substance of genes.
 Genes
 are the unit of inheritance that transmits information
from parents to offspring,
 are grouped into very long DNA molecules called
chromosomes, and
 control the activities of a cell.

 A species’ genes are coded in the sequences of the
four building blocks making up DNA’s double helix.
 All forms of life use essentially the same code to
translate the information stored in DNA into proteins.
 The diversity of life arises from differences in DNA
sequences.

 Diversity is the hallmark of life.
 Biologists have identified about 1.8 million species.
 Estimates of the actual number of species ranges from
10 to 100 million.
 Taxonomy names species and classifies them into a
system of broader groups.

 The diversity of life can be arranged into three
domains.
1. Bacteria are the most diverse and
widespread prokaryotes.
2. Archaea are prokaryotes that often live in
Earth’s extreme environments.
3. Eukarya have eukaryotic cells and include
 single-celled protists and
 multicellular fungi, animals, and
plants.

Domain Bacteria
Domain Archaea
Domain Eukarya
Bacteria
Archaea
Protists
(multiple kingdoms)
Kingdom Fungi Kingdom Animalia
Kingdom Plantae

 The history of life, as documented by fossils, is a saga
of a changing Earth
 billions of years old and
 inhabited by an evolving cast of life forms.

 In 1859, Charles Darwin published the book On the
Origin of Species by Means of Natural
Selection, which articulated two main points.
1. A large amount of evidence supports the idea of
evolution, that species living today are descendants of
ancestral species in what Darwin called ―descent with
modification.‖
2. Natural selection is a mechanism for evolution.

 Evolution is a core theme of biology.
 Evolutionary theory is useful in
 medicine
 agriculture
 forensics
 Conservation
 Human-caused environmental changes are powerful
selective forces that affect the evolution of many
species, including
 antibiotic-resistant bacteria,
 pesticide-resistant pests,
 endangered species, and
 increasing rates of extinction.

The word science is derived from a Latin
verb meaning ―to know.‖ Science is a way
of knowing.
Science is a process not a thing.

 How is a theory different from a hypothesis? A
scientific theory is
 much broader in scope than a hypothesis,
 usually general enough to generate many
new, specific hypotheses, which can then
be tested, and
 supported by a large and usually growing
body of evidence.

• General Stages of Scientific Investigation
1. Asking a Question
2. Collecting Information/Making
observations
3. Inferring and forming a hypothesis
4. Designing a controlled experiment to test
the hypothesis
5. Collecting/Analyzing Data (qualitative vs.
quantitative)
6. Drawing Conclusions

 Inference and imagination can lead to a hypothesis.
 If..then format
 Example:
 If artificial king snakes are placed in an environment
without coral snakes, then they will be attacked more
frequently than the artificial brown snakes.

 Variables – factors that change
 Independent – you manipulate (what you
deliberately change)
 Dependent – change in response to the
independent variable (variable that is measured)
 Control Group – used for comparison
 Nothing is changed

Case Study
 Scientists began with a set of observations and
generalizations
 poisonous animals are brightly colored and
 imposters resemble poisonous species but are actually
harmless.
 They then tested the hypothesis that mimics benefit
because predators confuse them with the harmful
species.

 The scientists conducted a controlled
experiment, comparing
 an experimental group consisting of artificial king
snakes
 a control group consisting of artificial brown snakes.
 The groups differed only by one factor, the coloration
of the artificial snakes.
 The data fit the key prediction of the mimicry
hypothesis.

Figure 1.9E
Coral snakes
present
Artificial
king snakes
Artificial
brown snakes
84%
0
20
40
60
80
100
Coral snakes
absent
17% 16%
Percentoftotalattacks
onartificialsnakes
83%

 Science is a social activity with most scientists
working in teams.
 Scientists share information in many ways.
 Science seeks natural causes for natural
phenomena.
 The scope of science is limited to the study of
structures and processes that we can directly observe
and measure.

 The graph below shows
the results of an
experiment in which mice
learned to run through a
maze.
1. State the hypothesis
that you think this
experiment tested.
2. Identify the variables
and control group.
3. What variables that
must have been kept
constant so as not to
affect the results
(validity).
4. Looking at the data
collected, does it
support the hypothesis?
Explain.

 Many issues facing society are related to
biology. Most involve our expanding technology.
 The basic goals of science and technology
differ.
 The goal of science is to understand natural
phenomena.
 The goal of technology is to apply scientific
knowledge for some specific purpose.

 Although their goals differ, science and
technology are interdependent.
 Technological advances stem from scientific
research.
 Research benefits from new technologies.

1. Describe seven properties common to all
life.
2. Describe the levels of biological
organization from molecules to the
biosphere, noting the interrelationships
between levels.
3. Define the concept of emergent
properties and describe an example of it.
4. Explain why cells are a special level in
biological organization. Compare
prokaryotic and eukaryotic cells.

5. Compare the three domains of life.
6. Describe the process and products of natural
selection.
7. Distinguish between quantitative and qualitative
data.
8. Distinguish between the scientific definition and
common use of the word theory.
9. Describe the structure of a controlled experiment
and give an example.
10. Compare the goals of science and technology.
Explain why an understanding of science is
essential to our lives.

Bio 2 ch1 Notes

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