The Seven Characteristics of Life
A. Display order: all forms of life including
this flower are arranged in a highly ordered
manner, with the cell being the fundamental
unit of life.
B. Harness and utilize energy: like this
hummingbird, all forms of life acquire energy
from the environment and use it to maintain
their highly ordered state.
C. Reproduce: all organisms have the ability
to make more of their own kind. Here, some
of the bacteria have just divided into two
D. Respond to stimuli: organisms can make
adjustments to their structure, function, and
behavior in response to changes in the
external environment. A plant can adjust the
size of the pore on the surface of its leaves to
regulate gas exchange.
organisms are able to
regulate their internal environment such
that conditions remain relatively constant.
Sweating is one way which the body
attempts to remove heat and thereby
maintain a constant temperature.
F. Growth and development: all organisms
increase their size by increasing the size and /
number of cells. Many organisms also change
over time. G. Evolve: populations of organisms change
over the course of generations to become
better adapted to the environment. The
snowy owl illustrates this perfectly.
Timeline for the evolution of major forms
of life: *when earth first formed it was too hot…it took 500 million years for
earth to cool down for life to exist
o Organic molecules that formed building blocks of life
could have been formed given conditions that prevailed
on primitive earth
o Reducing atmosphere that lacked oxygen
Hydrogen, methane, and ammonia
o Allows for synthesis of complex organic molecules
Biologically Important Macromolecules
4 major types of macromolecules important for all forms of
o Nucleic acid (DNA and RNA)
All except lipids are polymers made up from simpler building
blocks, and all are made within cells by complex metabolic
- Simulate conditions on
- Abiotic synthesis of