Download Document

Name ______________________________ Class ___________________ Date __________________
Skills Worksheet
Directed Reading (4.3 in textbook)
Section: Cycling of Matter
Read each question, and write your answer in the space provided.
1. What is the source of the energy that drives the water cycle? Explain.
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
2. Which of the cycles of matter involves the process of percolation?
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
3. What are the most important substances that pass through the cycles of matter?
_______________________________________________________________
Complete each statement by underlining the correct term or phrase in the
brackets.
4. The process that returns water to the atmosphere from the surface of lakes and
oceans is called [evaporation / transpiration].
5. Water that falls to Earth as rain or snow and seeps into the soil
becomes [surface water / ground water].
6. In the living portion of the water cycle, water is taken up by
[condensation / the roots of plants].
7. The process by which water evaporates from the leaves of plants
is called [respiration / transpiration].
Read each question, and write your answer in the space provided.
8. How does carbon become part of organic molecules?
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
Holt Biology
5
Ecosystems
Name ______________________________ Class ___________________ Date __________________
Directed Reading continued
9. List three ways carbon atoms return to the nonliving part of the carbon cycle.
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
Complete each statement by writing the correct term or phrase in the space
provided.
10. Organisms need nitrogen to build ______________________.
11. Phosphorus is usually present as ______________________
______________________ in soil and rock.
12. The process of combining nitrogen gas with hydrogen to form ammonia is
called ______________________ ______________________.
13. Nitrogen-fixing bacteria use ______________________ to split molecules of
nitrogen gas and combine the nitrogen atoms with hydrogen.
In the space provided, write the letter of the term or phrase that best completes the
statement or answers the question.
_____ 14. All of the following are examples of materials that cycle in ecosystems
except
a. energy.
b. oxygen.
c. water.
d. nitrogen.
_____ 15. Which is one way in which carbon dioxide enters the atmosphere?
a. percolation
b. photosynthesis
c. combustion
d. evaporation
_____ 16. Bacteria return nitrogen to the soil by which process?
a. denitrification
b. assimilation
c. nitrification
d. ammonification
Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
Holt Biology
6
Ecosystems