# BIOL102 Lab 1

Topics: Water, Hypothesis, Agar Pages: 16 (1686 words) Published: November 20, 2014

UMUC Biology 102/103
Lab 1: Introduction to Science
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, such as water. Since many living organism requires oxygen to survive, it is a necessary component of water systems such as streams, lakes and rivers in order to support aquatic life. The dissolved oxygen is measured in units of ppm (parts per million). Examine the data in Table 4 showing the amount of dissolved oxygen present and the number of fish observed in the body of water the sample was taken from; finally, answer the questions below.

Post-Lab Questions
1. What patterns do you observe based on the information in Table 4? As the parts per million of dissolved oxygen increases by 2 parts per million the number of fish observed increases. Once the PPM reaches 12 the ratio of fish declines showing diminishing returns.

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. A body of water may affect the parts per million of dissolved oxygen and the number of fish observed. If the dissolved oxygen levels increase, then the number of fish observed will also increase. 3. What would your experimental approach be to test this hypothesis? Collect water samples from a river, lake and stream in the same area and observe which body of water has the most dissolved oxygen level and record the number of fish observed. Compare the number of fish observed to the level of dissolved oxygen in each body of water sample.

4. What would be the independent and dependent variables?
The independent variables would be the water samples. The water samples are consistent (type of water, body of water, geographical area, aquatic life). The dependent variables would be the number of fish in the tested area which would indicate if there was any correlation with the effects of the dissolved oxygen levels.

5. What would be your control?
The control would be the same amount of water collected from each body of water from the same body type of water (fresh water, pond, lake, stream, etc).

6. What type of graph would be appropriate for this data set? Why? A bar graph would be appropriate because it would clearly show the correlation between the dissolved oxygen levels and number of fish.

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

8. Interpret the data from the graph made in Question 7.
As the dissolved oxygen increases by 2 parts per million the number of fish observed increases except when the dissolved oxygen increases from 12 parts per million to 14 parts per million the number of fish in the population decreases showing the fish population diminishing. As the PPM increases from 14 to 18 the fish population begins to increase again.

Exercise 2: Experimental Variables
Determine the variables tested in the each of the following experiments. If applicable, determine and identify any positive or negative controls.
Observations
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...