Biology Drosophila Lab Report
This guide is to help you write a formal experimental lab report similar to one that is used in upper-level
courses and college.
Section 1: Background (Approximately 1/3-1/2 page)
This section is mainly to give the reader an insight on what your experiment was and why you
performed it in the first place. Information to include may be some basic explanation of what you were
testing. Explain what genetics is and how you are testing it in your experiment. Review what dominant
and recessive traits are and how they are inherited. Explain why Drosophila melanogaster is a great
subject to test as opposed to another animal. How did you tell a male from a female? Also talk about
your mutations that you tested for and how you were able to decipher them from wild-type flies. Feel
free to include 1-3 pictures. This can also be the section of your report where you state your hypothesis,
but you should not include any of your data or conclusions just yet.
Section2: Materials and Methods (Approximately ½ - 3/4 page)
This section is where you explain to readers how your experiment was performed. Its purpose is to show
others that your experiment was controlled and consistent. While it does not need to be extremely
detailed, it needs to be informative enough that anyone could read this and repeat your experiment.
Many times people will replicate your experiment to see if they get the same results as you. When
writing your method, you can assume that readers have a basic understanding of this procedure. For
example, you can say “We then anesthetized the flies for approximately 45 seconds” instead of “We
tapped the vial so the flies fell into an empty one where we then dipped our Q-tip into the anesthetizer
and used it to anesthetize the flies.” This section should include dates, steps, etc. Also include a table
with your fly log to show a rough schedule of your experiment.
Section 3: Results (1/2-3/4 page)
This section is used to show the results of your experiment. Its easiest to show your data in graphs and
tables. It also makes it easier for you and the readers to interpret your data. Information to include
would be the experimental and expected numbers for both F1 and F2 offspring. Tables are good for
getting information, bar graphs are good for comparisons (i.e. wild-type vs. eyeless) Only give your data
in this section, do not discuss why you may have gotten those numbers.
Here’s a sample bar graph made on a google spreadsheet:
Section 4: Discussion ( ½ - 1 page)
This is the “meat” of your lab report. Here is where you explain your results from the data section. First
talk about your results from the F1 generation. Talk about why you got what you did/didn’t. Use a
Punnett square to support your ratios. If you didn’t get what you expected explain why. Then move on
to your F2 data. Again discuss why you got the results that you did. Use Punnett squares, ratios, etc. to
explain the data.
Sample Punnett Square:
E
E= eyeless
e= wildtype
e
E
E e
E
E
e
E
E e
E
Ee
E
E e
E
Make a conclusion. What is dominant, recessive, sex-linked, etc. as they pertain to your specific
experiment. Did you have to revise your hypothesis a few times?
This is also the section of the report where you report any experimental error. Did you have to restart
your experiment? If so, why? Did you over-anesthetize? Wait too long to type and sex them? Also give
ideas or ways that you could improve your experiment results or advice to those who may seek to
replicate what you did.