Posted: June 14th, 2020

Bi 102 lab 2 writing assignment how did oxygen generation by elodea

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BI 102 Lab 2 Writing Assignment
How did oxygen generation by Elodea vary in dark and light conditions?
This assignment requires you to evaluate a hypothesis and communicate the results of your
experiment O2 generation by Elodea under different conditions. The questions below are meant to
guide you to reporting the key findings of your experiment and help you think through how to
explain the findings and draw conclusions from them in a scientific manner. Because you’ve
already had an opportunity to practice these skills once, this assignment is worth 16 points.
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.
A grading rubric is provided on the second page of this assignment. To earn full points on your write up,
you must provide answers that align to the “meets” column of your grading rubric as well as meeting all
“Quality of Writing and Mechanics” elements described in the rubric. There are also some tips on pages 3-4
of this assignment to help you succeed.
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.
• 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.
DUE DATE: Your write up is due at the beginning of class next week. Late assignments will have 1 point
deducted per day up to 5 days, at which point the assignment will be assigned 0 points.
Hypothesis and Prediction – Part 1 of Rubric
1. What did you think was going to happen in this experiment and why? You may find it helpful to state your
answers to these questions as an “if-then” hypothesis-prediction. Be sure you have included a biological
rationale that explains WHY you made this 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 by Elodea in dark and in light conditions? Answer this question by creating
a bar 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- Mechanics Checklist
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. (Perhaps your lab manual? Your textbook? A website?) 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.
Please print out and submit this cover sheet with your lab writeup!
Lab Writeup Assignment (1) Assessment Rubric- 16 points total Name: ________________________________________
Element Misses (1 point) Approaches (3 points) Meets (5 points)
Hypothesis
Clarity/Specificity
Testability
Rationale
___Hypothesis is unclear and hardto-understand
___Hypothesis is not testable
___No biological rationale for
hypothesis or rationale is fully
inaccurate
___Hypothesis included is clearly
stated, but not specific or lacks
specific details
__Hypothesis is testable, but not in a
feasible way in this lab
___Some foundation for hypothesis,
but based in part on biological
inaccuracy
___Hypothesis included is clearly
stated and very specific
___Hypothesis is testable and could
be tested within lab parameters
___Rationale for hypothesis is
grounded in accurate biological
information
Graph
Title
Axes
Variables
Key
Graph clarity
Data accuracy
___Graph lacks a title
___Axes are not labeled
___Variables not addressed in graph
___No key or way to tell data points
apart
___Graph is hard to read and
comparisons cannot be made:
Inappropriate graph type or use of
scale
___Data graphed is inaccurate or
does not relate to experiment
___Graph has a title that is not very
descriptive
___Axes are either unlabeled, or
units are unclear or wrong
___Variables addressed in graph, but
not on correct axes
___Key included, but is hard to
understand
___Graph is somewhat readable,
comparisons can be made with
difficulty: Appropriate graph type, but
not scaled well
___Data graphed is partially
accurate; some data is missing
___Graph has a concise, descriptive
title
___Axes are labeled, including
clarification of units used
___Variables on correct axes
___A clear, easy-to-use key to data
points is included
___Graph is clearly readable and
comparisons between treatments are
easy to make: Graph type and scale
are appropriate to data
___Data graphed is accurate and
includes all relevant data, including
controls (if needed)
Analysis
Hypothesis
Scientific language
Data addressed
Explanation
___Hypothesis is not addressed
___Hypothesis is described using
language like proven, true, or right
___No explanations for data patterns
observed in graph or data does not
support conclusions.
___No biological explanation for data
trends or explanations are completely
inaccurate
___Hypothesis is mentioned, but not
linked well to data
___Hypothesis is not consistently
described as supported or refuted
___Some data considered in
conclusions but other data is ignored.
Any unusual “outliers” are ignored
___Explanations include minimal or
some inaccurate biological concepts
___Hypothesis is evaluated based
upon data
___Hypothesis is consistently
described as supported or refuted
___All data collected is considered
and addressed by conclusions,
including presence of outliers,
___Explanations include relevant and
accurate biological concepts
Quality of Writing and Mechanics: Worth 1 point. Writeup should meet all of the following criteria!
Yes No
☐ ☐ Write up includes your name, the date, and your lab section
☐ ☐ Write up is free from spelling and grammatical errors (make sure you proofread!!)
☐ ☐ Write up is clear and easy-to-understand
☐ ☐ Write up includes full citation for at least one reference with corresponding in-text citation
☐ ☐ All portions of write up are clearly labeled, and question numbers are included
Plagiarism refers to the use of original work, ideas, or text that are not your own. This includes cut-and-paste from websites,
copying directly from texts, and copying the work of others, including fellow students. Telling someone your answers to the
questions (including telling someone how to make their graph, question #2), or asking for the answers to any question, is cheating.
(Asking someone how to make the graph for this assignment is NOT the same as asking for help learning excel or some other
software). All forms of cheating, including plagiarism and copying of work will result in an immediate zero for the exam, quiz, or
assignment. In the case of copying, all parties involved in the unethical behavior will earn zeros. Cheating students will be
referred to the Student Conduct Committee for further action. You also have the right to appeal to the Student Conduct
Committee.
I have read and understand the plagiarism statement. ____________________________________________________
Signature
Guidelines for Good Quality Scientific Reports
Hypothesis and Prediction: The hypothesis is a tentative explanation for the phenomenon. Remember
that:
• 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.
Examples*:
I think that diet soda will float and regular soda will sink.
{This hypothesis misses the goal. It is not specific as we don’t know where the sodas are floating and
sinking, and it does not provide any explanation to explain why the hypothesis makes sense}
Because diet soda does not contain sugar and regular soda does, the diet soda will float in a bucket of
water, while regular soda will sink.
{This hypothesis approaches the goal. It is more specific about the conditions, and it provides a partial
explanation about why the hypothesis makes sense, but the connection between sugar and sinking is
unclear}
If diet soda does not contain sugar, then its density (mass/volume) is lower than that of regular soda
which does contain sugar, and so diet soda will float in a bucket of water while regular soda sinks.
{This hypothesis meets the goal. It is specific and the rationale- sugar affects density and density is what
determines floating or sinking in water- is clearly articulated}
*Note that these examples are for different experiments and investigations and NOT about your
photosynthesis lab. They are provided only to help you think about what you need to include in your write
up.
Graph: The graph is a visual representation of the data you gathered while testing your hypothesis.
Remember that:
• 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:
{This graph misses the goal. There is no title, nor is there a key to help distinguish what the data points mean. The
scale is too large- from 0 to 100 with an increment of 50, when the maximum number in the graph is 23- 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?}
{This graph meets the goal. There is a descriptive title, and all of the axes are clearly labeled with units. There is a key
so that we can distinguish what each set of data points represent. 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.}
0
50
100
Number
Stream location
Arthropod Abundance in Oregon Streams
0
5
10
15
20
25
Little Luckiamute Nestucca Neskowin Rickreall
Total number of species
Stream location
Arthropod Abundance in Oregon Streams
Insects
Crustaceans
Other Arthropods
Analysis: You need to evaluate your hypothesis based on the data patterns shown by your graph.
Remember that:
• 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.
Examples:
I was right. Diet Pepsi floated and so did Apricot Nectar. Regular Pepsi sank. Obviously the regular
Pepsi was heavier. This helps us understand the concept of density, which is a really important one.
{This analysis misses the goal. The hypothesis isn’t actually mentioned and the data is only briefly described. There is
no explanation of the importance of the Apricot Nectar results. Finally, there is no connection to how these results
help understand density or why it is biologically important}
I hypothesized that diet soda would float, and all three cans of diet Pepsi did float while the regular
Pepsi sank. This supports my hypothesis. Both types of Pepsi were 8.5 fluid ounces in volume, but the
regular Pepsi also contained 16 grams of sugar. This means that the regular Pepsi had 16 more grams
of mass provided by the sugar in the same amount of volume. This would lead to an increase in
density, which explains why the regular soda cans sank. When we put in a can of Apricot Nectar,
which had 19 grams of sugar, it floated. This was unexpected, but I think it is explained by the fact
that an Apricot Nectar can had a volume of 7 fluid ounces, but the dimensions of the can are the
same as that of a Pepsi can. A same-sized can with less liquid probably has an air space that helped it
float. The results of this experiment help us understand how the air bladder of a fish, which creates
an air space inside the fish, helps it float in the water and also how seaweeds and other living things
with air spaces or other factors that decrease their density keep from sinking to the bottom of the
water.
{This analysis meets the goal. It clearly ties the hypothesis to the results and outlines what they mean. It describes
how the results support the hypothesis, but also explains a possible reason behind the unusual results of the Apricot
Nectar. Finally, there is a link to how this experiment helps us understand biology}

emai. [email protected]

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