In the Water: In the Plants

Print Version
(Size - 21KB)

OREGON BENCHMARKS

Benchmark 1

Describe the basic needs of living things.

Benchmark 2

Describe basic plant structures and their functions.

USA NATIONAL SCIENCE EDUCATION CONTENT STANDARDS

Grades K-4

Systems, order, and function.

Systems, order, and organization.
Structure and function of living systems.
Understanding about scientific inquiry.

VICTORIAN LEARNING OUTCOMES

Biological Science:

3.1 Describe environmental factors that affect the survival of living things.

4.1 Identify relationships between living things which help them survive in their habitat.

CONTENT OBJECTIVES

Learners will be able to do the following:

Explain a wetlands capability to cleanse water through storage of soluble substances in living plants.
Explain that any natural system can become overloaded with too many contaminants.

PROCESS OBJECTIVES

Learners will be able to do the following:

Make observations.
Ask questions that can be answered through scientific investigation.
Design an investigation to answer a question.
Collect, organize, and summarize data from an investigation.
Analyze and interpret data from an investigation.

What Can We Learn About Plants at the Pond?

Lesson C - In the Water: In the Plants

FYI

Wetlands play an important role in maintaining water quality. Water enters the wetland from surface runoff or from ground water. Either of these water sources may bring with them fertilizers and other waterborne contaminants.

Many things may be dissolved in the water that moves through plants. If the water carries pollutants, these pollutants may be left in the plant; if the plant is one used for food, then these pollutants may get into the people or animals who eat them.

In the summer when plants are actively growing, nutrients and contaminants are absorbed by wetland plants. In the fall and winter when plants die and decay, these nutrients are released. There is a lower concentration of nutrients in water from runoff and ground water in the winter so ecosystems downstream can generally make good use of these released nutrients.

Wetlands have been called natural “water treatment Operations.” In a time when humans introduced fewer pollutants and less silt to the waters entering wetlands, they were very efficient indeed.

Today heavy metals, petroleum products, and fertilizers are more abundant in the environment. Wetland’s ability to purify water can be exceeded, resulting in degradation of other parts of the environment. As you study the ability of plants to remove contaminants from the system, remind students that the ultimate answer is to reduce the amount of these pollutants in the environment.

MATERIALS

• “It’s in the Water” (PDF - 26KB) data sheet, one copy per team
• Two sets of two plastic water cups per team, 250 ml polypropylene beakers
• Red food coloring
• Vinegar
• Two measuring cups, 250 ml polypropylene beakers
• One paring knife per team
• Several bunches of fresh celery stalks
• One ruler per team indeed.

PROCEDURE

Divide the group into two teams. Give each team two plastic cups and two stalks of celery. Have the learners trim the bottom end off each celery stalk. No stalk should be longer than 11 Inches. Use stalks with leaves if possible. Label the plastic cups with masking tape: cup “A,” cup “B.”

In Cup A put 3/4 cup water, several drops red food coloring, and 1/4 cup vinegar. Add a trimmed celery stalk. In Cup B put 1 cup water, several drops red food coloring, and a trimmed celery
stalk.

Place all the cups near a window and leave them there for a minimum of 4 hours, overnight, or up to several days. Ask the learners what they think will happen to each celery stalk. How will the results in Cup A differ from Cup B? Have the learners answer the questions on page 1 of the Data Sheet with what they expect to find for each celery stalk. If you are doing this activity as a demonstration, place the celery in the prepared cups 48 hours before you will show it to the learners.

When the celery has been soaking a sufficient amount of time, some red color may show on
the celery stalks that have leaves. Ask the learners to observe their celery stalks beginning with Cup B. For this part of the investigation, learners will need a ruler, a knife, and a piece of notebook paper. Each team should answer all the questions on the data sheet. After the teams have completed their observations, bring the group back together and compare results.

Could anyone tell, just by looking at the celery stalks, that a substance other than red colored
water was in one of the celery stalks? If the pollutant in the water used by the celery stalk had no color, no odor, and no taste, how would we know it was there?