Chapter 1
The Science of Life
Table of Contents
Section 1 The World of Biology
Section 2 Themes in Biology
Section 3 The Study of Biology
Section 4 Tools and Techniques
Chapter 1
Section 1 The World of Biology
Objectives
• Relate the relevance of biology to a person’s daily life.
• Describe the importance of biology in human society.
• List the characteristics of living things.
• Summarize the hierarchy of organization within complex
multicellular organisms.
• Distinguish between homeostasis and metabolism and
between growth, development, and reproduction.
Chapter 1
Section 1 The World of Biology
Biology and You
• Biology and Society
– Biology is the study of life and can be used to
both solve societal problems and explain aspects
of our daily lives.
Chapter 1
Section 1 The World of Biology
Biology
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Chapter 1
Section 1 The World of Biology
Characteristics of Life
• Living things share the same 7 characteristics:
organization and cells, response to stimuli,
homeostasis, metabolism, growth and development,
reproduction, and evolution.
Chapter 1
Section 1 The World of Biology
The Seven Properties of Life
Chapter 1
Section 1 The World of Biology
Characteristics of Life, continued
• Organization and Cells
– Organization is the high degree of order within an
organism’s internal and external parts and in its
interactions with the living world.
– A cell is the smallest unit of an organism that can
perform all life’s processes.
Chapter 1
Section 1 The World of Biology
Characteristics of Life, continued
• Organization and Cells
– Multicellular organisms are made up of many
cells and show a hierarchy of organization going
from the organism to the atom.
Chapter 1
Section 1 The World of Biology
Characteristics of Life, continued
• Response to Stimuli
– Another characteristic of life is that an organism
can respond to a stimulus—a physical or chemical
change in the internal or external environment.
Chapter 1
Section 1 The World of Biology
Characteristics of Life, continued
• Homeostasis
– All living things have mechanisms that allow them
to maintain stable internal conditions.
Homeostasis is the maintenance of a stable level
of internal conditions even though environmental
conditions are constantly changing.
Chapter 1
Section 1 The World of Biology
Characteristics of Life, continued
• Metabolism
– Metabolism is the sum of all the chemical
reactions that take in and transform energy and
materials from the environment.
Chapter 1
Section 1 The World of Biology
Characteristics of Life, continued
• Growth and Development
– The growth of living things results from the division
and enlargement of cells.
– Development is the process by which an
organism becomes a mature adult.
Chapter 1
Section 1 The World of Biology
Characteristics of Life, continued
• Reproduction
– Living organisms pass on hereditary information
from parents to offspring, also called
reproduction.
Chapter 1
Section 1 The World of Biology
Characteristics of Life, continued
• Change Through Time
– Populations of living organisms evolve or change
through time.
Chapter 1
Section 1 The World of Biology
Evolution
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Chapter 1
Section 2 Themes in Biology
Objectives
• Identify three important themes that help explain the
living world.
• Explain how life can be diverse, yet unified.
• Describe how living organisms are interdependent.
• Summarize why evolution is an important theme in
biology.
Chapter 1
Section 2 Themes in Biology
Diversity and Unity of Life
• Unity in the Diversity of Life
– Life is so diverse,or full of variety. Yet, life is also
characterized by unity, or features that all living
things have in common.
Chapter 1
Section 2 Themes in Biology
Diversity and Unity of Life, continued
• Unity in the Diversity of Life
– The tree of life shows that all living things have
descended with modification from a single
common ancestor. Yet, there are many different
lineages, or branches, representing different
species.
Chapter 1
Section 2 Themes in Biology
Phylogenetic Diagram of Living Organisms
Chapter 1
Section 2 Themes in Biology
Diversity and Unity of Life, continued
• Three Domains of Life
– The three domains of life are Bacteria, Archaea,
and Eukarya.
– The six kingdoms include Archaea, Bacteria,
Protista, Fungi, Plantae, and Animalia.
Chapter 1
Section 2 Themes in Biology
Interdependence of Organisms
• Organisms live in interdependent communities and
interact with both organisms and the environment.
Chapter 1
Section 2 Themes in Biology
Evolution of Life
• Evolution, or descent with modification, is the
process in which the inherited characteristics within
populations change over generations.
• Evolution helps to explain how species came to exist,
have changed over time, and adapt to their
environment.
Chapter 1
Section 2 Themes in Biology
Evolution of Life, continued
• Natural Selection
– Natural selection is a process by which
organisms that have certain favorable traits are
better able to survive and reproduce successfully
than organisms that lack these traits.
– Natural selection can lead to the evolution of
populations.
Chapter 1
Section 2 Themes in Biology
Natural Selection
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Chapter 1
Section 3 The Study of Biology
Objectives
• Outline the main steps in the scientific method.
• Summarize how observations are used to form hypotheses.
• List the elements of a controlled experiment.
• Describe how scientists use data to draw conclusions.
• Compare a scientific hypothesis and a scientific theory.
• State how communication in science helps prevent
dishonesty and bias.
Chapter 1
Section 3 The Study of Biology
Science as a Process
• Steps of the Scientific Method
– The scientific method involves making
observations, asking questions, forming
hypotheses, making predictions, designing
experiments, analyzing data, and drawing
conclusions.
Chapter 1
Section 3 The Study of Biology
Scientific Processes
Chapter 1
Section 3 The Study of Biology
Scientific Method
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Chapter 1
Section 3 The Study of Biology
Observing and Asking Questions
• The process of science begins with an observation.
• An observation is the act of perceiving a natural
occurrence that causes someone to pose a question.
Chapter 1
Section 3 The Study of Biology
Forming a Hypothesis
• A hypothesis is a proposed explanation for the way
a particular aspect of the natural world functions.
Chapter 1
Section 3 The Study of Biology
Forming a Hypothesis, continued
• Predicting
– To test a hypothesis, scientists make a prediction
that logically follows from the hypothesis.
Chapter 1
Section 3 The Study of Biology
Designing an Experiment
• Performing the Experiment
– A controlled experiment compares an
experimental group and a control group and only
has one variable.
Chapter 1
Section 3 The Study of Biology
Controlled Experiment and Variable
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Chapter 1
Section 3 The Study of Biology
Designing an Experiment, continued
• Performing the Experiment
– The control group provides a normal standard
against which the biologist can compare results of
the experimental group.
– The experimental group is identical to the control
group except for one factor.
Chapter 1
Section 3 The Study of Biology
Designing an Experiment, continued
• Performing the Experiment
– The experimenter manipulates the independent
variable.
– The experimenter measures the dependent
variable because it is is affected by the
independent variable.
Chapter 1
Section 3 The Study of Biology
Independent and Dependent Variables
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Chapter 1
Section 3 The Study of Biology
Designing an Experiment, continued
• Testing the Experiment
– Experiments should be conducted without bias
and they should be repeated.
Chapter 1
Section 3 The Study of Biology
Collecting and Analyzing Data
• Analyzing and Comparing Data
– Scientists analyze data to draw conclusions about
the experiment performed.
Chapter 1
Section 3 The Study of Biology
Drawing Conclusions
• Making Inferences
– An inference is a conclusion made on the basis of
facts and previous knowledge rather than on direct
observations.
Chapter 1
Section 3 The Study of Biology
Drawing Conclusions, continued
• Applying Results and Building Models
– Scientists often apply their findings about the
natural world to solve practical problems.
Chapter 1
Section 3 The Study of Biology
Constructing a Theory
• A theory is a set of related hypotheses confirmed to
be true many times, and it can explain a great
amount of data.
Chapter 1
Section 3 The Study of Biology
Communicating Ideas
• Publishing a Paper
– Scientists submit research papers to scientific
journals for publication.
– In peer review, the editors of a journal will send
submitted papers out to experts in the field who
anonymously read and critique the paper.
Chapter 1
Section 3 The Study of Biology
Honesty and Bias
• Communication between scientists about their
methods and results helps prevent dishonesty and
bias in science.
Chapter 1
Section 3 The Study of Biology
Honesty and Bias
• Conflict of Interest
– The threat of a potential scandal based on
misleading data or conclusions is a powerful force
in science that helps keep scientists honest and
fair.
Chapter 1
Section 4 Tools and Techniques
Objectives
• List the function of each of the major parts of a
compound microscope.
• Compare two kinds of electron microscopes.
• Describe the importance of having the SI system of
measurement.
• State some examples of good laboratory practice.
Chapter 1
Section 4 Tools and Techniques
Microscopes as Tools
• Light Microscopes
– A compound light microscope is a microscope
that shines light through a specimen and has two
lenses to magnify an image.
– Four major parts of a compound light microscope
are the ocular lens, objective lens, stage, and light
source.
Chapter 1
Section 4 Tools and Techniques
Microscopes as Tools
• Light Microscopes
– The eyepiece magnifies the image.
– The objective lens enlarges the specimen.
– The stage is a platform that supports slides with
specimens.
– The light source is a light bulb that provides light
for viewing images.
Chapter 1
Section 4 Tools and Techniques
Microscopes as Tools, continued
• Magnification and Resolution
– Magnification is the increase of an object’s
apparent size.
– Resolution is the power to show details clearly in
an image.
Chapter 1
Section 4 Tools and Techniques
Object Size and Magnifying
Power of Microscopes
Chapter 1
Section 4 Tools and Techniques
Microscopes as Tools, continued
• Electron Microscopes
– In an electron microscope, a beam of electrons
produces an enlarged image of the specimen.
– Electron microscopes provide greater
magnification and resolution than light
microscopes.
Chapter 1
Section 4 Tools and Techniques
Microscopes as Tools, continued
• Electron Microscopes
– Scanning electron microscopes pass a beam of
electrons over the specimen’s surface for better
viewing the external surface of a specimen.
– Transmission electron microscopes transmit a
beam of electrons through a thinly sliced specimen
for better viewing the internal structures of a
specimen.
Chapter 1
Section 4 Tools and Techniques
Units of Measurement
• Base and Other Units
– Scientists use a single, standard system of
measurement, called the metric system. The
official name of the metric system is Système
International d’Unités or SI.
Chapter 1
Section 4 Tools and Techniques
Units of Measurement
• Base and Other Units
– The metric system has seven base units.
Chapter 1
Section 4 Tools and Techniques
Safety
• Good Laboratory Practice
– Lab safety involves safe and common-sense
habits such as never working alone in a lab or
without proper supervision by the teacher.