Introduction
to Life
Science
What is Life?
What Characteristics do
all Living Things Share?
1.All living things have a
cellular organization.
A cell is the basic unit of life.
Unicellular- one celled
Multicellular- more than one cell
2.
Cells are composed of
chemicals.
Water- the most abundant
Carbohydrates- for energy
Proteins and lipids- building
materials
Nucleic Acids- contain
genetic material
3. Living things react to
stimuli.
A stimulus is something in
the environment that causes a
reaction, or a response.
A response is an action or
change in behavior.
4. Living things grow
and develop.
Growth- an increase in the size
of an organism.
Development- a progressive
change in an organism over
time.
All living things have the
ability to reproduce.
5.
All living things arise from other
living things.
The theory of Spontaneous
Generation, which proposed that
life can appear spontaneously from
non-living things, was disproved by
experiments performed by Redi
and Pasteur.
Life Comes from Life
• Living things come from living
things.
• 400 years ago people though
that living things came from
non-living things (Spontaneous
Generation).
• Francisco Redi, Louis Pasteur
did experiments to disprove
this theory.
Redi’s Experiment
Do Now!
Answer questions #1-3 on
pages 18-19 in your
workbooks.
6. All living things use
energy.
Energy is used to nourish,
repair and create new cells.
We obtain energy from
converting the foods that we
eat into energy that can be
used by the cells.
7. All living things can
move.
This process is called
Locomotion.
Plants move their branches and
leaves toward the Sun!
8.All living things will
die.
One of the realities of life is that
all life eventually comes to an
end. This process is called
Expiration.
Do Now!
Answer question #4 on
page 20 in your
workbook.
What do All Living
Things Need to Survive?
1. Water****
2. Food
3. Living space
4. Stable internal
conditions
(Homeostasis)
How do Organisms
Obtain Food for Energy?
• Autotrophs- make their own
food (Plants).
• Heterotrophs- obtain food
from other sources.
 Herbivore- eat plants.
 Carnivore- eat animals
(meat).
 Omnivore- eat plants and
animals.
Do Now!
Answer questions #5,6 on
page 21 in your
workbook.
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