Lab1 - Introduction to Science

Exercise 1: Data Interpretation (2 pts each)

1. What patterns do you observe based on the information in Table 4?

Ans: No fish are present when the dissolved oxygen is zero. When there is more dissolved oxygen in the water, more fish are present. However, the number of fish tends to drop or level off when the dissolved oxygen is higher than 12 ppm.

2. Develop a hypothesis relating to the amount of dissolved oxygen measured in the water sample and the number of fish observed in the body of water.

Possible Hypotheses:

1. The amount of dissolved oxygen affects the number of fish that can live in a body of water.

2. As dissolved oxygen concentration increases, more fish can live in the body of water.

3. There is an ideal dissolved oxygen concentration for fish to live in.

3. What would your experimental approach be to test this hypothesis?

Possible Experimental Approach: Deposit an equal number of fish in several tanks. Maintain all other variables (temperature, light, food, etc.), but vary the dissolved oxygen concentration in each of the tanks. Observe the fish over time to determine how many fish can survive at different oxygen concentrations.

4. What are the independent and dependent variables?

Independent Variable: Dissolved oxygen concentration.

Dependent Variable: The number of fish.

5. What would be your control?

Possible Control: Aquarium with no fish. Measure the dissolved oxygen level in a fish tank at normal room conditions, and repeat this measurement every time you make an observation of the number of fish. [Use only one type of fish for your experiment, and control other variables such as light, food and temperature.]

6. What type of graph would be appropriate for this data set? Why?

A line graph is most appropriate because it can best display the relationship between the variables.

7. Graph the data from Table 4: Water Quality vs. Fish Population (found at the beginning of this exercise).

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8. Interpret the data...