biology writing

Writing Assignment – 30 points

How did oxygen generation by Elodea vary in different light wavelengths?

ASSIGNMENT : Please respond to the following questions to complete your laboratory write up. For this assignment you will only focus on O2 generation experiment. Make sure that your write up is accurate, and clearly written so that it is easily readable.

FORMAT :

· Type your responses, using 1.5 or double-spacing.

· Include the section headings (Hypothesis, Results, Analysis) and question number (example: 1, 2, 3, etc) in your answers but do not rewrite the question. You may choose to include information about your methodology but that is not a required element of this write up.

· Graphs may be made with a computer program (example: Microsoft excel, Mac numbers, etc) or may be neatly produced with a ruler on graphing paper.

· Print out the cover sheet on page 2 of this assignment, read and sign the academic honesty statement, and submit it with your write up. Your instructor WILL NOT accept a write up without the signed cover sheet.

Hypothesis and Prediction – Part 1 of Rubric

1. You should make a prediction about what you thought was going to happen in this experiment and provide the testable explanation or hypothesis on which that prediction is based. You may find it helpful to state your answers to these questions as an “if-then” prediction and because hypothesis. Be sure you have included a biological rationale that explains your hypothesis/prediction. Think about what is required for and what is produced by the process of photosynthesis.

Results – Part 2 of Rubric

2. How much O2 was generated each interval by Elodea in different colored and full spectrum light conditions? Answer this question by creating a connected dot-plot graph that shows the results of your experiment. If you need assistance building a graph, there is a Guide to Graphing resource available on your Moodle lab course site.

Analysis- Part 3 of Rubric

3. Explain why you think that the results shown in your graph support or refute your hypothesis

(remember we never “prove” anything in science). Consider all your data and the overall data pattern as you answer this question. Don’t ignore unusual data that may not seem to fit into a specific patterns (“outliers”). Explain what you think might be behind these unusual data points.

4. What is the biological significance of your results? What biological concepts explain completely why these events happened in the experiment? How do these results help you understand the process of photosynthesis? Think about giving a specific example.

References

5. Provide at least one full citation (make sure you include an in-text citation that pinpoints where you used this resource) for a resource you made use of in performing the experiment, understanding the concepts and writing this assignment. Your lab manual must be cited if you refer to it, but you should also use an additional reference, as the lab manual is more a guide to how to conduct the experiment, and other resources will provide additional biological information to help you make sense of your experiment. If you used more than one resource, you need to cite each one! If you need help with citations, a Guide to Citing References is available on your Moodle lab course site.

Guidelines for Good Quality Scientific Reports

Hypothesis and Prediction: The hypothesis is a tentative explanation for the phenomenon.

· A good hypothesis and prediction is testable (and should be testable under the conditions of our lab environment; For example, if your hypothesis requires shooting a rocket into space, then its not really testable under our laboratory conditions).

· Your explanation can be ruled out through testing, or falsified.

· A good hypothesis and prediction is detailed and specific in what it is testing.

· A good hypothesis provides a rationale or explanation for why you think your prediction is reasonable and this rationale is based on what we know about biology.

· A good prediction is specific and can be tested with a specific experiment.

Graph: The graph is a visual representation of the data you gathered while testing your hypothesis.

· A graph needs a concise title that clearly describes the data that it is showing.

· Data must be put on the correct axes of the graph. In general, the data you collected (representing what you are trying to find out about) goes on the vertical (Y) axis. The supporting data that that describes how, when or under what conditions you collected your data goes on the horizontal (X) axis. (For this reason time nearly always goes on the X-axis).

· Axes must be labeled, including the units in which data were recorded

· Data points should be clearly marked and identified; a key is helpful if more than one group of data is included in the graph.

· The scale of a graph is important. It should be consistent (there should be no change in the units or increments on a single axis) and appropriate to the data you collected Examples:

0

50

100

Number

Month

{This graph misses the goal. There is no title, nor is there a key to help distinguish what the data points mean; the lines are difficult to distinguish from one another. The scale is too large- from 0 to 100 with an increment of 50, when the maximum number in the graph is 25- and makes it hard to interpret this graph. The x-axis is labeled, but without units (the months) and the y-axis has units, but the label is incomplete- number of what?}

0

5

10

15

20

25

30

March

April

May

June

July

Number of individuals

Month (2011)

Seasonal changes in population size of three different madtom catifish in

the Marais de Cygnes River in Spring/Summer 2011

Brindled madtom

Neosho madtom

Slender madtom

{This graph exceeds the goal. There is a descriptive title that conveys the essence of the hypothesis, and all of the axes well scaled and are clearly labeled with units. There is a key that works in greyscale . The dependent variable (number of individuals) is correctly placed on the y-axis with the independent variable of time placed on the x-axis. The scale of 0-30 is appropriate to the data, with each line on the x-axis representing an increment of 5.}

Analysis: You need to evaluate your hypothesis based on the data patterns shown by your graph. You use data to determine support or refute your hypothesis. It is only possible to support a hypothesis, not to “prove” one (that would require testing every possible permutation and combination of factors). Your evaluation of your hypothesis should not be contradicted by the pattern shown by your data.

· Refer back to the prediction you made as part of your hypothesis and use your data to justify your decision to support or refute your hypothesis.

· In the “if” part of your hypothesis you should have provided a rationale, or explanation for the prediction you made in your hypothesis (“then” part of hypothesis”). Use this to help you explain why you think you observed the specific pattern of data revealed in your graph.

· You should consider all of the data you collected in examining the support (or lack of support for your hypothesis). If there are unusual data points or “outliers” that don’t seem to fit the general pattern in your graph, explain what you think those mean.