Biology – Writing Lab Reports

Here is an example of one of my lab reports:

Immune System Lab Report

Problem: How long does it take to thoroughly wash your hands?

Hypothesis: I believe that it will take 25 seconds.
Materials:

1. Timer or watch that counts seconds
2. Sink
3. Blindfold
4. Washable paint
5. Paper towels
6. Soap
7. Partner (this can be a friend or family member)
8. Newspaper to protect the work surface (optional)

Procedure:

1. Pick one person to be the hand washer and one person to be the timekeeper. You will both have the opportunity to complete each of the experiments, so you will each be washing your hands two times.For each trial of this experiment, the timekeeper (the partner not washing hands) will be responsible for determining the cleanliness of the washer's hands at each time interval. Use the following scoring guide as a reference.

   **Discuss as a team the factors that you will use to determine the level of cleanliness observed at each time interval before you get started.**

2. Washer #1 should put a small amount (about a tablespoon) of washable paint on the palm of one hand and spread it evenly over both hands. Be sure to cover the backs of the hands and the skin next to and under the fingernails. Allow the paint to dry completely.
3. Go to the sink and blindfold Washer #1 so he or she can't see his/her hands. Turn on warm (not scalding hot!) water. Have Washer #1 wash with just water for one second. After one second, have the timekeeper blot dry the washer's hands by very lightly touching the paper towel to the skin (do not rub!). Use the scoring guide to record the cleanliness on the "water only" data table in the row marked "Washer #1." Do not let Washer #1 see his/her hands, and be sure that you do not give away any hints about how clean they are.
4. Have the washer wash for four more seconds with just water. Again, lightly blot the washer's hands and record their cleanliness in the data table.
5. Have the washer wash for 15 seconds more with water. Once again, blot and record the cleanliness on the data table.
6. Take the blindfold off and allow the washer to completely clean his/her hands.
7. Change roles and repeat steps 2 through 6 with Washer #2. Record these results on the second row of the data table, under "Washer #2."
8. Now change roles again so that Washer #1 is back to the role of hand washer. Repeat steps 2 through 6, having the washer use soap each time. Record the results in the appropriate row of the data table.
9. It is now time for Washer #2 to repeat steps 2 through 6 using soap each time. Record these results in the second row of the data table.

Data and Observations:

Water Only:

Water and Soap:

Conclusion:

The four trials were mostly the same other than the difference in the washing patterns of the 1^st and 2^nd washer. There were a few errors that could have come to pass during the course of this experiment; the first could have been an inconsistency with the soap. If it was not the right kind or if it was incapable of washing off paint, this could have impacted the experiment. Also, if the paint was water resistant but was not labeled as such it would not have washed off, leaving the experiment with false results. Lastly if the timer was not working properly it could have left the washer with extra time to wash also provoking false results. If I could improve this lab report so that there would be the least amount of mistakes possible, I would list in the materials a certain brand of whatever was needed, and that it must be purchased (not be taken out of a cupboard, if you already had the product). Also, the 2^nd washer (assuming the 1^st washer is the student completing the lab report) should be shown a specific way to wash their hands so that both washers wash the same way, leaving no room for variation.

Based on my results the effective time for washing hands is around 20 seconds (this is indicated by the graphs), but the use of soap does not wash molecules off your skin it instead kills bacteria, which is proven since both graphs got the same results. The areas of the hand that retained the most paint and required much scrubbing to clean were: in between fingers, under nails and upper wrists. The graphs indicated that the time to effectively wash your hands was 20 seconds or more, and that you must scrub while washing to completely remove all bacteria.

The body has many mechanisms to fight pathogens on the inside and the outside of the body. On the outside, there is the skin which protects your body from pathogens entering directly. There is also the nose which filters the air we breathe; the mouth and eyes use tears and saliva to break down pathogens and refuse to allow them to enter the body. On the inside, there is the inflammatory response which sends out cells to rid the body of whatever has succeed in entering it, these defensives we have just listed are nonspecific; the specific defense mechanism is the immune system which produce B lymphocytes and T lymphocytes who are always patrolling the body in search of pathogens to consume; B and T lymphocytes are white blood cells. Washing your hands aids the body by ridding it of pathogens and bacteria, that could otherwise enter your eyes or mouth and infect you.