Transcript View of Life - Biology Junction

Biology
Solomon • Berg • Martin
Chapter 1
A View of Life
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology
CHAPTER 1 A View of Life
• The Human Genome Project mapped
the complete set of human genes
• Genomics analyses the DNA
sequence of an organism
• While genomics will lead to
breakthroughs in science, it also
raises ethical concerns
• Safeguarding the privacy of genetic
information, for example
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology
CHAPTER 1 A View of Life
• Living organisms composed of cells
• Unicellular organisms
–Single cell
• Multicellular organisms
–Many cells organized to form
tissues, organs, and organ systems
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology
CHAPTER 1 A View of Life
• Cells
• Plasma membrane regulates
passage of materials
• Specialized molecules (usually
DNA) contain genetic instructions
• Internal structures called
organelles perform specific
functions
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology
CHAPTER 1 A View of Life
• Types of cells
• Prokaryotic cells, exclusive to
bacteria and microscopic
organisms
• Eukaryotic cells contain a variety
of organelles, including a
nucleus, which houses DNA
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology
CHAPTER 1 A View of Life
• Biological growth
• Increase in the size of cells, the
number of cells, or both
• Development
• Includes all the changes that take
place during an organism’s life
• Structures and body form are
adapted to an organism’s
functions
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology
CHAPTER 1 A View of Life
• Metabolism processes
• Chemical reactions and energy
transformations
• Essential to nutrition, growth and
repair of cells, and conversion of
energy
• Regulation of metabolic
processes maintains
homeostasis
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology
CHAPTER 1 A View of Life
• Stimuli
• Physical or chemical changes in
the internal or external
environment
• The organism responds to, for
example, changes in
–Light
–Temperature, pressure, or sound
–The chemical composition of soil
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology
CHAPTER 1 A View of Life
• Locomotion
• Simpler organisms
–Amoeboid movement
–The beating of cilia or flagella
• Animals
–Move by contracting muscles
–Some are sessile and have cilia or
flagella
• Plants respond to light, water, etc.
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology
CHAPTER 1 A View of Life
Asexual reproduction and sexual reproduction
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology
CHAPTER 1 A View of Life
• Adaptation
• Populations evolve to better
survive
• Adaptations
–Characteristics that enhance an
organism’s ability to survive in a
particular environment
–May be structural, physiological,
behavioral, or a combination
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology
CHAPTER 1 A View of Life
The hierarchy
of biological
organizations
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology
CHAPTER 1 A View of Life
• The cell
• Consists of atoms and molecules
• Is the basic unit of life
• In multicellular organisms,
associates to form tissues
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology
CHAPTER 1 A View of Life
• Tissues
• In animals, an example is muscle
• In plants, an example is epidermis
• Tissues are organized into
organs
• Tissues and organs form organ
systems
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology
CHAPTER 1 A View of Life
• Population
• Members of a species that live in
the same area at the same time
• Community
• Populations that live together and
interact
• Ecosystem
• A community and the environment
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology
CHAPTER 1 A View of Life
• To carry on life processes, an
organism must have
• Precise instructions
• Communication among cells
• This information is coded and
delivered by
• Chemical substances
• Electric impulses
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology
CHAPTER 1 A View of Life
• DNA is the large molecule that
makes up genes
• Genes specify instructions for
making every living organism
• Watson and Crick worked out
structure of DNA in 1953
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology
CHAPTER 1 A View of Life
DNA consists of two
chains of atoms
twisted into a helix
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology
CHAPTER 1 A View of Life
• DNA contains “recipe” for
proteins
• Proteins determine structure and
function of cells and tissues
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology
CHAPTER 1 A View of Life
• In multi-cellular organisms,
communication with and among
cells is critical
• Some proteins are important in
this communication
• Cell-to-cell communication is a
complex process called cell
signaling
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology
CHAPTER 1 A View of Life
• Information transmitted from one
part of the body to another is
important in regulating life
processes
• Information is transmitted by
• Hormones
• Neurotransmitters and their
receptors
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology
CHAPTER 1 A View of Life
• Evolution is the unifying concept
of biology
• Biology
• Hierarchical classification scheme
• Identifies the approximately 1.7
million species of living organisms
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology
CHAPTER 1 A View of Life
• Systematics studies the diversity
of organisms and their
evolutionary relationships
• Taxonomy is the science of
naming and classifying organisms
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology
CHAPTER 1 A View of Life
• Binomial system of
nomenclature
• Developed in the 18th century by
Linnaeus, a Swedish botanist
• Names and classifies organisms
• Basic unit is a species
• Each species assigned a two-part
name
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology
CHAPTER 1 A View of Life
• Binomial system of
nomenclature uses a series of
taxonomic categories from
species to domain
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology
CHAPTER 1 A View of Life
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology
CHAPTER 1 A View of Life
Each category is
more general and
more inclusive
than the one
below it
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology
CHAPTER 1 A View of Life
• Natural selection
• Theory of evolution developed by
Darwin and Wallace
• The Origin of Species by Natural
Selection published in 1859
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology
CHAPTER 1 A View of Life
• Natural selection based on four
observations
• Members of a species show
variation
• Organisms produce many more
offspring than will survive
• Organisms compete
• Only some survive to reproduce
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology
CHAPTER 1 A View of Life
Egg masses of
the wood frog—
Many more
produced than
can survive
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology
CHAPTER 1 A View of Life
• Variation among individuals
• Result of different varieties of
genes that code each
characteristic
• Ultimate source of variation is
random mutation
–Chemical or physical changes in
DNA that can be inherited
–Modifies genes
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology
CHAPTER 1 A View of Life
• Every cell of an organism
requires nutrients
• Certain nutrients are used as
fuel for cellular respiration
• Virtually all cells carry on cellular
respiration
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology
CHAPTER 1 A View of Life
• A self-sufficient ecosystem
contains three types of
organisms
• Producers
• Consumers
• Decomposers
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology
CHAPTER 1 A View of Life
• Ecosystems depend on
continuous input of energy
• Organisms can neither create
energy nor use it with complete
efficiency
• During every energy transaction,
some is lost to the environment
as heat
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology
CHAPTER 1 A View of Life
Energy
flow
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology
CHAPTER 1 A View of Life
• The scientific method involves
systematic thought
• Deductive reasoning draws
conclusions from premises
• Inductive reasoning begins with
observations and draws
conclusions or extrapolates
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology
CHAPTER 1 A View of Life
The scientific
method involves
ordered steps
•
•
•
•
Hypothesis
Method
Results
Conclusion
Copyright © 2005 Brooks/Cole — Thomson Learning