When do plants undergo photosynthesis?
When do plants undergo respiration?
Materials: 2 vials labeled “Light”; 2 vials labeled “Dark”; 2 vials not labeled; Elodea (water plant); straw; 1 jar with Bromothymol Blue (BTB); eye dropper; 1 glass measuring flask; 1 measuring cup; plastic knife; scissors; sparking water
Procedures:
1.) Fill the glass flask ½ way with water. Use eyedropper and put drops of (BTB) in water and stir with plastic knife until water turns blue. (Do Not Drink Water!!)
2.) Choose one group member to blow through straw. Place straw bottom in base of jar and gently blow bubbles in jar until liquid changes color. Why does liquid change color?
3.) Dark Experiment:
a.) Fill two vials labeled “Dark” with water. Fill up to top. Put 5 drops of (BTB) in both vials.
b.) Cut a 3-inch piece of Elodea and stick in one vial. Put cap on each vial tightly. (One vial has BTB, H20, & Plant; one vial has BTB, H20 ONLY)
c.) Place vials in a dark cabinet.
4.) Light Experiment:
a.) Put 5 squirts of (BTB) in 2 vials labeled “Light”.
b.) Carefully open sparkling water bottle and pour into vials until filled to top. What color is BTB? Why?
c.) Cut a 3-inch piece of Elodea and stick in one vial. Put cap on each vial tightly.
d.) Put both vials in a sunny spot. What will happen? Why?
5.) Create a hypothesis using the questions above and your own observations.