Snail

1
Snail Elodea Lab

• General Biology
• Laboratory Notes

2
Introduction

• Plant Producer
• Can utilize light to make food as it grows.
• Snail Consumer
• Cannot manufacture its own food.
• Must consume organic compounds produced by plants
  and/or other animals.

3
Photosynthesis

• Carbon Dioxide Water Suns Energy ? Food
  Energy

4
Respiration

• Occurs in plants and animals.
• Plants respire as they grow, circulate nutrients,
  and utilize energy.

5
Indicator

• A substance that shows the presence of a chemical
  substance by changing color.
• Bromthymol Blue, (BTB) Indicator that changes to
  a green or yellow color in the presence of an
  acid.

6
Demonstration

• Blow into a straw that is immersed in water and
  BTB.
• 1) Do you see a color change?
• 2) If so, why?

7
Why did the water change color?

• Carbon dioxide (CO2) forms an acid when dissolved
  in water
• H20 CO2 ? H2CO3 (Carbonic Acid)
• In this experiment, bromthymol blue can be used
  to indicate, indirectly, the presence of CO2 and
  the dominance of respiration.
• Lab Set-Up.

8
Lab Observations

• Take down observations of each tube for the
  starting day on your observation sheet.
• Then, on a sheet of paper titled Snail Elodea
  Lab, write your hypothesis about what will
  happen to each tube during this experiment.
• Tubes A1, A2, A3, A4 Light 1st Night
• Tubes B1, B2, B3, B4 Dark 1st Night