chapter 1 introduction: themes in the study of life
TRANSCRIPT
Chapter 1Introduction: Themes in the Study of
Life
Biology: Scientific study of life
Bio- = life
The phenomenon we call life defies a simple, one-sentence definition
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Properties of Life
(c) Response to the environment
(a) Order
(d) Regulation
(g) Reproduction (f) Growth and development
(b) Evolutionary adaptation
(e) Energy processing
Themes of Biology
Identifiable common themes Makes study of complex
subject more manageable
Pay attention as we move through semester
We will see evidence of themes many times
Theme: Hierarchy of Life
Biological systems are much more than the sum of their parts
Emergent properties
New properties emerge with each step upward in the hierarchy of biological order
Reductionism
Involves reducing complex systems to simpler components that are more manageable to study
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Hierarchy of Life
From atoms to organisms
Cell
4.) Cells
6 6.) Organs and organ systems
7 5.) Tissues
3.) Organelles
50 µm
10 µm
1 µm
1.) Atoms
2.) Molecules
Theme: Organisms Interact with Other Organisms and their
Environment Organisms exist in constant
interaction with other living organisms and the physical world
Nutrients and other vital materials are cycled through living organisms, into the environment and back again
Global climate change is just one of many examples of this interaction
Theme: Energy Transfer and Transformation
Activities of life
Require organisms to perform work, which depends on an energy source
The exchange of energy between an organism and its surroundings
Often involves the transformation of one form of energy to another
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Energy Conversion
Energy flows through an ecosystem Usually entering as sunlight and exiting as
heat
Producers(plants and other
photosynthetic
organisms)
Consumers
(including animals)
Sunlight
Chemical
energy
Heat
Heat
Ecosystem
Theme: Structure and Function
Things are constructed based on their function
Ex. Wheels are round so they can roll so they can move a vehicle
Can you think of some biological examples of structure and function?
Theme: The Cell The cell is the lowest level of organization
that can perform all activities required for life
All living organisms are made of cells
Types of Cells All cells share certain characteristics
They are all enclosed by a membrane
They all use DNA as genetic information
There are two main forms of cells
Prokaryotic: No membrane bound nucleus
Eukaryotic: Does have membrane bound nucleus
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Prokaryotic cells vs. Eukaryotic cells
EUKARYOTIC CELL
Membrane
Cytoplasm
Organelles
Nucleus (contains DNA) 1 µm
PROKARYOTIC CELL
DNA
(no nucleus)
Membrane
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Theme: The Cell’s Heritable Information
Cells contain chromosomes made partly of DNA, the substance of genes
Which program the cell’s production of proteins and transmit information from parents to offspring
Egg cell
Sperm cell
NucleicontainingDNA
Fertilized eggwith DNA fromboth parents
Embyro’s cells with copies of inherited DNA Offspring with traits
inherited fromboth parents
Theme: Evolution Main theme of biology
Evolution explains diversity and unity of all living organisms on our planet
Organization: Three Domains of Life
At the highest level, life is classified into three domains
Bacteria
Archaea
Eukarya
Organization: Three Domains of Life
Domain Bacteria and Domain Archaea
Consist of prokaryotes
Domain Eukarya, the eukaryotes, includes
Multiple kingdoms: Protista
Kingdom Plantae
Kingdom Animalia
Kingdom Fungi