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Objectives
- Understand the sources of Nitrates and the role that Nitrates
play in an ecosystem
- Describe the effects of excess Nitrates on water quality
and human health
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Pre-Test
Multiple-choice items make up the pre-test.
Printed copies of the exams have been provided for your students.
Access the answer key (among the resources above) to check your
students' answers.
Post-Test
Multiple-choice items make up the post-test.
Printed copies of the exams have been provided for your students.
Access the answer key (among the resources above) to check your
students' answers.
Lesson
Presentation
This lesson introduces the students to the concepts
of nitrates. The students will gain an understanding of the
chemical nature of nitrates and how nitrogen is used in an ecosystem.
This is depicted in a diagram that shows a part of the nitrogen
cycle and the flux of nitrogen in an environment. The students
will be introduced to the idea that nitrogen is present in different
forms (i.e. ammonia) and is changed as it travels through an ecosystem.
Further, the students will learn the causes of excess nitrates in
the environment, specifically bodies of water and how excess amounts
of nitrates affect water quality, organisms that live within the
water and human beings.
Activity
The activity is designed to help the students
appreciate the response of goldfish to different levels of nitrates
in the water.
Note: This experiment is intended to show how the goldfish
are impacted by varying the level of nitrates in the water. It is
expected that you will not get a measurable difference in the activity
of the goldfish if the experiment is conducted without
"conditioning" the water.
It would be ideal if the beakers could be left out for 3-4 weeks
for algae to multiply. This would more accurately show the
effects of excess nitrates in the water. It is expected that
you would then see a more dramatic difference between the fish in
different nitrate levels. Also, two to three days before the experiment
is performed, the beakers could be covered (with say, aluminum foil)
to simulate nighttime and you could then notice how the algae bloom
changes the dissolved oxygen level in the beakers.
Tools
and Resources
Software
used in the lesson:
Microsoft WORD
Microsoft Internet Explorer or Netscape Navigator
 
Introduction
| Objectives | Pre-Test
| Presentation | Activity
| Post-Test
PEER Curriculum
| Water
Quality Modules | Teacher's
Pages | Standards
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