the scientific method.

INSTRUCTIONS:

· On your own and without assistance, complete this Lab 1 Answer Sheet electronically and submit it via the Assignments Folder by the date listed in the Course Schedule (under Syllabus).

· To conduct your laboratory exercises, use the Laboratory Manual located under Course Content. Read the introduction and the directions for each exercise/experiment carefully before completing the exercises/experiments and answering the questions.

· Save your Lab 1 Answer Sheet in the following format: LastName_Lab1 (e.g., Smith_Lab1).

· You should submit your document as a Word (.doc or .docx) or Rich Text Format (.rtf) file for best compatibility.

Exercise 1: Data Interpretation

Dissolved oxygen is oxygen that is trapped in a fluid. Since many living organisms require oxygen to survive, it is a necessary component of water systems (streams, lakes, rivers, etc.). Dissolved oxygen is measured in units of parts per million (ppm). Examine the data in Table 4, which shows the amount of dissolved oxygen present in a body of water and the number of fish observed in the sample. Then, answer the questions below.

Table 4: Water Quality vs. Fish Population

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

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.

What would your experimental approach be to test this hypothesis?

What would be the independent and dependent variables?

What would be your control?

Exercise 2: Experimental Variables

Determine the variables tested in each of the following experiments. If applicable, determine and identify any positive or negative controls.

1. A study is being done to test the effects of habitat space on the size of fish populations. Different sized aquariums are set up with six goldfish in each one. Over a period of six months, the fish are fed the same type and amount of food. The aquariums are equally maintained and cleaned throughout the experiment. The temperature of the water is kept constant. At the end of the experiment, the number of surviving fish are surveyed.

A. Independent Variable:

B. Dependent Variable:

C. Controls:

To determine if the type of agar affects bacterial growth, a scientist cultures E. coli on four different types of agar. Five petri dishes are set up to collect results:

• One with nutrient agar and E. coli

• One with mannitol-salt agar and E. coli

• One with MacConkey agar and E. coli

• One with LB agar and E. coli

• One with nutrient agar but NO E. coli

A. Independent Variable:

B. Dependent Variable:

C. Controls:

Exercise 3: Testable Observations

Determine which of the observations below are testable. For those that are testable:

· Determine if the observation is qualitative or quantitative.

· Write a hypothesis and a null hypothesis.

· What would be your experimental approach?

· What are the dependent and independent variables?

· What are your controls - both positive and negative?

· How will you collect your data?

· How will you present your data (e.g., charts, graphs, types)?

· How will you analyze your data?

Observations

1. A plant grows 3 cm faster per day when placed on a window sill than it does when placed on a coffee table in the middle of the living room.

The bank teller with brown hair and brown eyes is taller than the other tellers.

When Sally eats healthy foods and exercises regularly, her blood pressure is 10 points lower than when she eats fatty foods and does not exercise.

The Italian restaurant across the street closes at 9 pm, but the restaurant two blocks away closes at 10 pm.

For the past two days, the clouds have come out at 3 pm, and it has started raining at 3:15 pm.

George did not sleep at all the night following the start of Daylight Savings Time.

Exercise 4: Conversion

Use Figure 9 to convert each value into the designated units.

Figure 9: Conversions for temperature, time, mass, and length.

1. 46,756,790 mg = _______ kg

5.6 hours = ________ seconds

13.5 cm = ________ inches

47 °F = _______ °C

©eScience Labs, 2018

©eScience Labs, 2018