Chapter 1 Lesson 1
 All
living things are organized.
 They grow and develop.
 They reproduce.
 They respond.
 They maintain certain internal conditions.
 They use energy.
 Organisms
 What

is the smallest unit of life?
Cell
 Unicellular


Only one cell
Specialized structures
 Multicellular


Two or more cells
Different cells perform different functions
 Growth

Unicellular

 Development

Increase in size
Changes that occur
during lifetime


Multicellular

Increase in number of
cells

Specialization of cells
Explain the
development of a
frog
 Unicellular

Asexual reproduction – cell division
 Multicellular

Sexual reproduction
 Internal

Hunger, thirst, fatigue
 External

stimuli
stimuli
Light, temperature, sights, sounds
 How
can an external stimulus create an
internal stimulus?
 Ability
to maintain internal conditions when
outside conditions change

Fever, shivering, sweating, collecting excess
water
 Why
is maintaining homeostasis important to
organisms?

Homeostasis ensures that an organism can
function.
 Why
do you think the human body cannot
maintain homeostasis for very long in water
that is less than 10 degrees C?
 Everything
an organism does requires energy.
 What
is the source of energy for almost all
life on Earth?

Almost all life on Earth gets energy from the Sun.
 From
which food sources does the badger in
Figure 6 get energy?

The badger gets energy from the snake, lizard,
and squirrel.
 What
do the arrows leading to the pronghorn
from the desert paintbrush and from the
pronghorn to the mountain lion mean?

The arrows mean that the pronghorn gets energy
feeding on the desert paintbrush, and the
mountain lion gets energy by eating the
pronghorn.
 Why
is there no arrow leading away from the
mountain lion?

There is no arrow leading away from the
mountain lion because the mountain lion is a top
predator and is at the top of this food chain.