The Characteristics of Life
 Cellular
Organization
 Reproduction
 Heredity
 Metabolism
 Homeostasis
 Responsiveness
 Growth and Development
Cellular Organization
 All
life is made up of one or more cells.
 A bacteria is made up of one cell, but plants and
animals have even more.
 How many cells do humans have?

10 to 50 trillion cells!
 Each
cell in the body does a special job, and
working together they make an organism.
What kinds of cells are there?
Reproduction
 All
organisms need a way to make more of
themselves.
 There are a variety of different ways that
organisms reproduce.

Sexual Reproduction
 Eggs
 Live
Birth
 Broadcast Spawning

Asexual Reproduction
 Binary
Fission
 Mitosis
 Fragmentation
Heredity
All organisms pass traits on to their offspring.
 Your father’s nose, your mother’s hair are all traits
that you have inherited from your parents.
 These traits are passed on through DNA.
 Every organism we know of in the world uses DNA
to pass on it’s genetic code.

Metabolism
 Metabolism
is a sum of all the chemical reactions
in an organism.



Metabolism is broken into two parts.
Catabolism breaks down molecules and releases
energy.
Anabolism creates new molecules and uses energy.
 Anabolic
steroids help build proteins which are added
to muscles.
 All
organisms require energy to do pretty much
anything.
Homeostasis
 From
greek, Homeo – the same, and Stasis –
standing still.
 Homeostasis is a stable state of conditions in an
organism’s body that are necessary for life.



Body Temperature
Water balance
Blood pH
Responsiveness
 All
organisms respond to things in their
environment.
 We call these thing that organisms respond to
stimuli.







Light
Temperature
Odor
Sound
Gravity
Heat
Pressure
Growth and Development
 All

organisms grow and develop.
Development is a change in the physical or
physiological make-up of an organism.
 Without
growth, each generation would get
smaller and smaller.
 Metabolism helps create the energy that fuels
growth and development.
The Unifying Themes of Biology
 Cellular
Structure and Function
 Homeostasis
 Metabolism
 Reproduction
 Heredity
 Evolution
 Interdependence
Evolution
 Evolution
is the changes in the genetic makeup of
a population over time.
 Every species undergoes evolution, however,
some do it faster than others.
 Evolution acts on whole species, not on individual
organisms.
 What is a species?

A species is a group of organisms that are capable
of interbreeding and can produce fertile offspring of
both sexes.
What about hybrids?
Interdependence

All organisms depend on other for survival.

Or, as Elton John put it, there is a circle of life and it
moves us all.
 The
study of this interdependence between
organisms and the environments in which they
live is called ecology.
 This is one of the reasons environmental
protection is so important, just like all other
animals and life, humans rely on other organisms
to live and thrive.