NAME___________________________ DATE___________________ HOUR___________________

BIOLOGY I

A CLOSED ENVIRONMENT

CELL ENERGY - 10

PURPOSE: To investigate how plants and animals affect each others ability to live in a closed environment.

MATERIALS NEEDED: 4 test tubes, 2 animals (snails or fish), Parafilm paper, Bromthymol blue solution, and 2 small stalks of Elodea

PROCEDURE:

1. Label your test tubes A – H.

2. Prepare the tubes in the following manner:

A and E	One stalk of Elodea
B and F	One Snail
C and G	One Snail and one Elodea stalk
D and H	nothing

3. Tubes A, B, C, and D get just water. THESE WILL BE SET UP BY YOUR INSTRUCTOR.

4. Tubes E, F, G, and H each get an equal amount of the Bromthymol blue solution.

5. Seal the top of the tubes with the Parafilm.

6. Place the tubes in a test tube rack and place them close to the window.

TUBE SET UP

DATA TABLES

TABLE ONE – SOLUTION COLOR
	TUBE A	TUBE B	TUBE C	TUBE D
DAY ONE
DAY TWO
DAY THREE

TABLE TWO – SOLUTION COLOR
	TUBE E	TUBE F	TUBE G	TUBE H
DAY ONE
DAY TWO
DAY THREE

ANALYSIS QUESTIONS

:

1. Which test tubes were used as controls?__________________________________________

2. What color did the bromthymol blue solution turn?_________________________

3. What made the bromthymol blue solution turn color?

4. Fill in the following table:

	Tube A	Tube B	Tube C	Tube D	Tube E	Tube F	Tube G	Tube H
Final observed changes
What caused the change?

5. What is the relationship between photosynthesis and respiration.

6. Fill in the blanks in the following diagram.