Cycles of Matter A. 1. 2.

Name
Date
Class
Chapter 20
Lesson Outline
LESSON 2
Cycles of Matter
A. How does matter move in ecosystems?
1. Many types of
are used over and over again in the
environment.
2. The way water and gases move through ecosystems and are used over and over is
called a(n)
.
3. Most of Earth’s water is in the
.
4. The path water follows as it moves from Earth through the
and back to Earth is called the water cycle.
5. The three processes involved in the water cycle are evaporation, condensation,
and
.
a. Water changes from a liquid to a gas during the process
of
.
b.
changes back into liquid water during condensation.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
c. Rain, snow, sleet, and hail are examples of
.
B. The Nitrogen Cycle
1. Nitrogen is an important element in
, which all
organisms need to survive.
2. Nitrogen in
is essential to passing on genetic
information.
3. During the process of
, nitrogen changes from a gas into
a form that organisms can use.
a.
in the soil and water fix nitrogen gas in compounds
that organisms can use.
b. Some animals obtain the nitrogen they need when they eat
that have absorbed nitrogen compounds from the soil.
4.
in the soil break down dead organisms and animal wastes.
Thus,
Matter and Energy in the Environment
returns to the soil.
25
Name
Date
Class
Lesson Outline continued
C. The Oxygen Cycle
1. The process that is the main source of oxygen in Earth’s atmosphere
is
.
2. The oxygen cycle involves the change from oxygen to
and back again.
D. The Carbon Cycle
1. All organisms contain the element
.
2. When dead organisms decompose, carbon returns to the
and carbon dioxide is released into the atmosphere.
3. In the atmosphere, carbon appears as
.
4. The process through which thermal energy from the Sun is absorbed and keeps the
Earth warm is called the
.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
26
Matter and Energy in the Environment