Lab Manual.

Perform Lab and write report/ observations

Conduct the experiment in the Final Lab Manual. Fill out the questions in the lab manual to guide your experiment and organize your results and conclusions. Take pictures of your experiment prior to beginning once you have all of your equipment set up, in the middle of the experiment and at the end of the experiment. For each lab, create a “Student Information Card” to be pictured in each photo with:
• the name of the lab
• the date you are performing the lab
• your full name and signature
This card should be the approximate size of half of an 8×10 piece of paper, so that all information is clearly visible in your photo. This card should be displayed in each of the lab specific photos. If you do not include this card, you will receive 0 points on the lab report.
Record your detailed observations and results throughout the experiment. Once you have conducted the experiment and completed the Lab Report, write a 3 page lab report in essay format (MLA) summarizing the experiment, results and conclusions. See below for the grading rubric.
Detailed Instructions and Grading Rubric Midterm & Final Lab Reports
• Minimum length of 3 pages of text, double-spaced, not including pictures and figures. 20 points
• Lab Report must include the following sections (separated by bold headers corresponding to those below) 5 points
• Introduction: 2-3 paragraphs introducing the biological concepts covered in the lab, including references to sources. Last paragraph of introduction should contain 2-3 sentences introducing the lab design. 50 points.
• Methods: 2-3 paragraphs detailing the methods that you used to perform the lab. Do not cut and copy these from the lab manual. Write these in sentence form and do not use numbers or bullet pointed lists. Include every detail you performed so that the reader would be able to perform the lab exactly as you did if they were trying to repeat it. Include pictures/diagrams where necessary. 50 points.
• Results: 2-3 paragraphs summarizing the results of the experiment. Use the Lab manual as a guide for the type of information to include here. Create figures (bar plots, scatterplots, etc) in Microsoft Excel from the completed tables from the Lab manual. Do not insert the tables from the Lab manual into the document, as I expect further synthesis of these results. Insert pictures of the completed experiment. 50 points.
• Discussion & Conclusion: 2-3 paragraphs discussing the results of the experiment, what the results mean, and how they relate to the biological concept under study. Reference outside sources where appropriate. Discuss 2-3 errors while avoiding the term human error. (Random Error and Systematic Error) Include a paragraph on your experience and impressions of the lab and what you learned. 50 points.
• References: Include MLA properly formatted references and in-text citations. A minimum of three sources are required. (See Purdue OWL). 25 points.

Final Lab Report
Conduct the experiment by following the detailed instructions below. Fill out the tables and
answers the questions below to guide your experiment and organize your results and conclusions.
Take pictures of your experiment prior to beginning once you have all of your equipment set up,
in the middle of the experiment and at the end of the experiment. Record your detailed
observations and results throughout the experiment. Once you have conducted the experiment
and completed the questions/tables, write a 3 page lab report in essay format (MLA)
summarizing the experiment, results and conclusions. See grading rubric.
Introduction
Materials needed
Radish or other quick sprouting seeds
Paper towels
Salt
Zip lock bags or saran wrap
Six cups
Measuring cup
Measuring spoon
Red food coloring
Blue food coloring
Salt
Celery stalk
Introduction
The abiotic (non-biological) features of an ecosystem (e.g., climate, soil quality, water
availability) are important to understanding the biological community that comprises the
biotic component of an ecosystem. Water availability is particularly important to all life.
Freshwater makes up about one percent of the world’s water (Figure 6.1).
Fresh water scarcity limits the range of many terrestrial species of plants and animals. Plants,
like animals, have different tolerances to salt in their environment. All soils have some water-
soluble salts, and essential plant nutrients are absorbed
in this form. High salinity in the soil (the salt content)
makes it more difficult for plants to extract water from
the soil. Fresh water enters an ecosystem in the form
of precipitation, a river or lake, or an underground
aquifer (Figure 6.2). With human population growth,
intensive agricultural
practices and urban water demand, water levels in
many of the world’s aquifers are dropping. If fresh
water is pumped out of an aquifer at a rate exceeding
its natural recharge rate (from precipitation and
underground water channels) salt water and other
pollutants may intrude into the traditional aquifer basin. Salt water encroachment is a growing
problem in the aquifers of coastal communities.
Salty soil is also a problem that can arise in agriculture. As irrigation water is absorbed by plants
and evaporated by the sun, salts are left behind. Over time, salt may accumulate such that the soil
becomes too salty for many plants to grow. It is believed that the ancient population of Sumeria
first thrived with its practice of irrigation, but over many generations began to suffer reduced
crop yields due to the increasing salinity of the soil.
Experiment 1: Water Transport & Salinity

  1. Obtain four cups (two of which could have been used in Lab 5). As in Lab 5, fill each cup with
    400 ml of tap water. Use red dye to darkly stain two cups, and use blue dye to darkly stain the
    other two cups. Be sure that each red cup gets the same amount of dye and that each blue cup
    gets the same amount of dye. Record the drops in each. Add a spoonful of salt into each cup.
  2. Label one red dye cup and one blue dye cup with an S (high salt). Add 4 spoonfuls of salt to
    each of these cups. Stir the solutions thoroughly.
  3. Obtain two similar stalks of celery, each with some leaves at the top. Cut a 1-cm piece (about
    one-half inch) off the bottom of each stalk. Keep the relative lengths of the two stalks as similar
    as possible.
  4. Carefully, split the stalks up the middle about half-way. The stalks should each now have two
    “legs.” Be sure that the legs of each stock are similar sized (i.e., the left leg and right leg are the
    nearly the same length and width).
  5. Place the red S cup and the blue S cup together. Gently place one “leg” of one stalk into the
    red S cup, and the other “leg” of the stock into the blue S cup. The celery should now be
    “straddling” the two S cups (Figure 5.2.B). Place the red non-S cup and blue non-S cup together
    and situate the legs of the other celery stalk into each cup (i.e., the celery “straddles” these two
    non-S cups).
  6. Record the time at which you place each celery into the pairs of cups as “Start time.”
  7. Let the celery sit in the cups for 6 hours, or until you can see color in the leaves of one of the
    stalks. In Step 6 above, record the time when you remove the stalks as “Stop time.”
  8. Examine the top of the celery stalks. Are there differences between the celery in the high salt
    (S) and low salt (non-S) water conditions? Record your observations
  9. Remove the celery from the cups (be sure to keep it clear which came from the high
    saltsolution (S) and which came from the low salt (non-S) condition). Lay each stalk out
    flat.Starting at the top, move down the stalk, making cross-sectional cuts. Stop when you first
    seeevidence of dye. Measure how far up each stalk the red and blue dyes climbed. In Table 6.1,
    record the distance (cm) traveled by the red dye in high salt conditions (S), the blue dye in high
    salt conditions (S), the red dye in low salt conditions (non-S) and theblue dye in low salt
    conditions (non-S).
  10. Tear apart the celery stalk. Notice the feel of the vascular tissue, and how the food coloring
    lies within it.
    Experiment 2: Seed Germination & Environmental Conditions
    In this experiment, you will investigate germination of radish seeds in environments with
    different salt contents. You will prepare six germinating environments and monitor them over
    four days. Each germinating environment will be a plastic-encased, water-soaked paper towel.
  11. To prepare solutions of different salinity, collect 6 clean cups and label them: “1/2”, “1/4”,
    “1/8”, “1/16”, “1/32”, and “0”.
  12. Use a measuring spoon to add salt to 50 ml of water in a measuring cup (about ¼ cup). Add
    1.5 tablespoons of table salt (sodium chloride). Stir the water while adding the salt. The
    solubility of sodium chloride is ~36 grams per 100 mL of fresh water at 25 C. After vigorous
    stirring the solution you should still be able to see some remaining some salt crystals at the
    bottom of your solution. This indicates that you have reached the saturation point of salt in your
    water.
  13. Pour off 40 ml of salt water into the cup labeled ‘1/2.” Do not pour the un-dissolved salt. The
    “1/2” cup will then contain your saturated salt water solution.
  14. Clean your measuring cup, and fill each of the remaining cups with 40 ml of plain water.
  15. Add 40 ml of plain water to your salt solution in the “1/2” cup. You will then have 80 ml of a
    50% saturated saline solution in the “1/2” cup.
  16. Using your measuring cup as an intermediate, transfer 40 ml the 50% saturated solution (“1/2”
    cup) to the cup labeled “1/4”. The “1/4” cup will then hold 80 ml of a 25% saturated saline
    solution.
  17. Using your clean measuring cup as an intermediate, transfer 40 ml the 25% saturated solution
    (“1/4” cup) to the cup labeled “1/8”. The “1/8” cup will then hold 80 ml of a 12.5% saturated
    saline solution.
  18. Using your clean measuring cup as an intermediate, transfer 40 ml the 12.5% saturated
    solution (“1/8” cup) to the cup labeled “1/16”. The “1/16” cup will then hold 80 ml of a 6.3%
    saturated saline solution.
  19. Using your clean measuring cup as an intermediate, transfer 40 ml the 6.3% saturated solution
    (“1/16” cup) to the cup labeled “1/32”. The “1/32” cup will then hold 80 ml of a 3.1% saturated
    saline solution. You have now prepared a pure water solution in cup “0” and a 3.1%, 6.3%,
    12.5%, 25%, and a 50% saturated saline solution in cups “1/32”,”1/16”, “1/8”,”1/4”, and “1/2”
    respectively.
  20. Alternative experiment. You have six solutions ranging in concentration from 0% to a 50%
    saturated saline solution. You can run this experiment using each solution as the basis for a
    germinating environment and following the instructions as they stand. However, if you would
    like to discard one or two of the salt water solutions and use two solutions of your own design in
    their place, this is OK. Examples include using water with additives such as sugar, alcohol, soda,
    or bleach, or even running two at the same salt concentration to get a sense of the uncertainty.
    You can also use the above protocol to test the effects of even smaller salt concentrations. If you
    choose to run some alternatives, you still need to run pure water and at least three of the saline
    solutions, thus all of the rest of the salt concentration experiment still applies. If you do choose to
    run some alternatives, simply follow the directions below with the relevant change in mind. In
    the lab report, you will need to describe your alternative experiment(s) and their outcome(s)
    separately. Have fun!
  21. Prepare for seed germination. Take three paper towels and cut them in half. Fold each half
    towel in half. These towels will be the seeds’ germinating environment.
  22. Place a folded towel in each of the cups containing your salt solutions and possible
    alternatives. Make sure that each towel gets soaked with the solution and that you do not lose
    track of which one is which condition. Label one corner of each towel with the corresponding
    solution (e.g., “1/2”, “1/4”, etc.).
  23. Count out six piles of 15 or more radish seeds each. Make sure that each pile has the same
    number of seeds. If there are visible quality differences between seeds make sure that each pile
    has similar quality as well (e.g., discard cracked, broken, or discolored seeds).
  24. Remove the soaked towels from the cups and lay the seeds from each pile out in each one of
    the towels (Figure 6.3). Be careful not to mix up which towel came from which cup. Record the
    initial date (Day 0) in which you first put the seeds in the towels in Table 6.2 in Lab Report 6.
    Spread the seeds over only one half of the towel so that you can fold the other half over the
    seeds. You may even want to add another fold.
  25. Fold the towel up around the seeds in order to keep them wet, but you will also want to be
    able to unfold the towel to observe the germination process over the next four days. Wrap each
    wet towel with its seeds in saran wrap or in a sealed sandwich bag. This will insure that the water
    in the towel does not evaporate away. Make sure that each towel and seed set is labeled to match
    the corresponding solution(e.g., “1/2”, “1/4”, etc.), perhaps by marking the plastic bag or wrap,
    or by placing a labeled piece of paper in the bag/wrap.
  26. Find a safe location where your seed sets can stay for the next four days. Make sure that each
    set is in identical conditions. Monitor seed appearance and growth every day for the next four
    days. Unfold the wet towels carefully to avoid ripping the wet towel or fragile sprouts. Be sure to
    record the number of sprouts, changes over time, and differences that you notice between seed
    sets in Table 6.2 in Lab Report 6.

Sample Solution

ACED ESSAYS