Prentice Hall Science Explorer Life Science
Chapter 2 pages 34 - 67
All living things have
needs that must be
satisfied.
Stable
Internal
Conditions
Living Space
Need for Water
Food
COS 1 – Describe the characteristics common to living things, including growth
and development, reproduction, cellular organization, use of energy, exchange of
gases, and response to the environment.
Need for Water
• All living things need water to survive.
• Organisms need water to obtain
chemicals from the surroundings,
break down food, grow, move
substances within their bodies, and
reproduce.
• Most organisms can only live a few
days without water.
COS 1 – Describe the characteristics common to living things, including growth
and development, reproduction, cellular organization, use of energy, exchange of
gases, and response to the environment.
Need for Food
• Organisms need a source of energy to
live.
• Food is used as the energy source.
• Definition – Autotrophs (auto – self;
troph – feeder) make their own food.
– For example, plants capture the sun’s
energy to make their food.
COS 1 – Describe the characteristics common to living things, including growth
and development, reproduction, cellular organization, use of energy, exchange of
gases, and response to the environment.
Need for Food
• Definition – Heterotrophs (hetero –
other; troph – feeder) are organisms
that cannot make their own food.
• Heterotrophs obtain energy by
feeding on others.
• Some heterotrophs eat autotrophs
and some eat other heterotrophs
that eat autotrophs.
COS 1 – Describe the characteristics common to living things, including growth
and development, reproduction, cellular organization, use of energy, exchange of
gases, and response to the environment.
Need for Living Space
• All organisms need a place to live.
• An organism’s surroundings must be
able to provide what it needs to
survive.
• Organisms compete for space because
there is a limited amount of space on
Earth.
COS 1 – Describe the characteristics common to living things, including growth
and development, reproduction, cellular organization, use of energy, exchange of
gases, and response to the environment.
Need for Stable Internal
Conditions
• All organisms must be able to keep
the conditions inside their bodies
stable.
• Definition – Homeostasis is the
maintenance of stable internal
conditions.
• Homeostasis keeps internal conditions
just right for cells to function.
COS 1 – Describe the characteristics common to living things, including growth
and development, reproduction, cellular organization, use of energy, exchange of
gases, and response to the environment.
Microorganisms come from other
microorganisms.
Complex life comes only from
other life.
COS 1 – Describe the characteristics common to living things, including growth
and development, reproduction, cellular organization, use of energy, exchange of
gases, and response to the environment.
Stretching to the Limit @ home
Many people believe that
understanding how life arose on
Earth is one of the great
mysteries.
What do you believe about how life
arose on Earth?
COS 1 – Describe the characteristics common to living things, including growth
and development, reproduction, cellular organization, use of energy, exchange of
gases, and response to the environment.
Reading: Go back to the Moodle topic
outline page and click on the
resource titled “Origins of Life”.
Answer the Student Book questions
on the following slides in your
science notebook. Write the
questions and answers.
1. What did the idea of spontaneous
generation state?
2. Briefly, what does the chemical
evolution hypothesis state?
3. What does the Drake equation
attempt to show?
4. If the common chemicals in the
early atmosphere led to the
creation of the building blocks of
life, do you think the same thing
could happen elsewhere?