The Characteristics of Life
PreAP Biology
Ms. Haut
Biology


Study of life
Biologists recognize that all living things
share certain characteristics
Characteristics of Life
1.
Order


All living things
made of one or
more cells
Cells are the smallest
unit capable of all
life functions
Life at Its Many
Levels

Biologists
explore life at
levels ranging
from the
biosphere to the
molecules that
make up cells.
Figure 1.3
2.
Regulation

Maintenance of
stable internal
conditions despite
changes in external
conditions
(Homeostasis)
homestudy.ihea.com/wildlifeID/0
43jackrabbit.htm
Characteristics of Life
Characteristics of Life
3.
Growth and
Development


DNA directs pattern
of growth and
development
Pattern of growth
characteristic of
species
www.antarcticlife.com/.../emperor-penguin.html
Characteristics of Life
4.
Energy Utilization
 Sum of all chemical
reactions carried out
in an organism
(Metabolism)
 All energy originates
from the sun
 Plants convert solar
energy into sugar
 Animal use/store
energy in own
tissues
Characteristics of Life
5.
Response to the Environment


Organisms have evolved to
live and interact with other
organisms (Interdependence)
Ecology is the study of
interactions of living
organisms with one another
and their environment


Food webs
Respond to stimuli

Each organism interacts continuously with its
environment.


Both organism and environment are affected by the
interactions.
The dynamics of any ecosystem depend on two
processes:


Cycling of nutrients
Flow of energy
Figure 1.4
6.
Reproduction


Process of making more
of one’s own kind
No organism lives
forever; necessary part of
living
Heredity


Passing of traits from
parent(s) to offspring
Genes are inherited from
parent(s)
www.blue-room.com/animals/rosie/
Characteristics of Life
Characteristics of Life
7.
Evolution



Change over time
New species (group
of genetically similar
organisms that can
produce fertile
offspring) can
develop over time if
enough changes
occur
Natural selection—
survival of the fittest
Figure 1.11