Biology: The Study of Life
• Biology is the study of living things
• Living things are diverse
• Organisms are classified
– by cell type into Domains
– & other characteristics into
6 Kingdoms
The Six Kingdoms of Life Figure 1.1
What qualifies something as “living”
versus “non-living?”
• 5 Basic Properties of Life
• 1. Order & Organization
(Fig. 1-2)
– Cellular organization
– all living things are
comprised of at least one
cell
– Unicellular-one cell
– Multicellular- more than
one cell
The Organization of Life
• Living things function and interact with
each other on many levels
• The organization of life is a hierarchy of
levels of increasing complexity
– cellular
– organismal
– populational
Cellular Level Organization
Organism Level Organization
Population Level Organization
• 2. Sensitivity
– All organisms respond to stimuli
• 3. Growth and
reproduction
– all organisms have the
capacity for growth
and reproduction
Heredity
– all organisms pass
genetic information
across generations
from parents to
offspring
• 4. Regulation-
coordination of body
processes
– Metabolism
– all living things process
energy which is used to
power other processes
– Cellular Respiration,
Fermentation,
Photosynthesis
• 5. Homeostasis
– all living things maintain
stable internal
environments to optimize
conditions for metabolism
and other processes
Living or Not Living
• Your pet cat • Living
• A plant • Living
• Bacteria • Living
• Soccer ball • Not Living
• Mushroom • Living
• Mold • Living
• Flu Virus
• Not Living
Why are viruses not alive?
• Are viruses made of cells?
– NO
• Do viruses need energy?
– NO
• Do viruses use processes to maintain a stable internal environment
(Homeostasis)?
– NO
• Do Viruses Grow and Reproduce independently of a host organism?
– NO