Ecology

Rashad Gray

Biology Lab Group 1

Ecology

Problem: What is the effect of acid rain on seed germination?

Hypothesis: If tomato seeds are exposed to a pH of 2 and 4, then the seeds will not germinate.

Protocol:

Control: Water

Independent Variable: pH 2
Independent Variable 2: pH 4
Dependent Variable: Seed germination

1. Collect 3 petri dishes

2. Fill bottom, of petri dishes with soil, 3/4 full.

3. Check pH of bottle labels with pH strips.

4. Add 2 pH to one petri dish, 4 pH to 2nd petri dish, and water to third petri dish, add enough appropriate pH to each petri dish so that the soil is moist, but not soupy.

Provided Supplies:
Variety of flower, fruit and vegetable seeds.
Petri Dishes
pH solutions: Variety-may include pH 2.0, pH 4.0, pH 6.0, pH 7.0, pH 8.0, pH 10.0.
Different types of soil
Parafilm

Procedure:
For germination with soil, fill the bottom part of the Petri plate about 3/4 full of soil, add enough of appropriate pH solution so that the soil is wet but not soupy, then spread 6-8 seeds on the wet soil. Cover the plate and wrap the edges with parafilm. Repeat for each experimental condition to be tested. Allow to germinate for one week.

Research: What effect does acid rain have on seed germination?

Water becomes acidic when it mixes with certain chemicals. When water mixes with pollution and other chemicals from factories, power plants, and cars. These industrial processes are sent into the air, mix with water vapor, and enter the water supply through rain. The acid rain prevents germination. Not only are the seeds affected by the acid rain, but the soils basic nutrient system is also affected. Since acid rain destroys the soils nutrients, the seeds are unable to grow.

Conclusion:

Was your hypothesis supported? The tomato seeds in the petri dishes with pH 2 and pH 1 did not germinate. We believe this is due to the acidity of the water in these petri dishes.