- Obtain the necessary supplies:
- some means of taking notes and recording your findings (computer or paper and writing utensil)
- at least 3 clean glass jars with lids
- some low-salt beef or chicken broth
- a pot large enough to contain the jars in some water to boil them
- a smaller pot to boil some of the broth
- In one jar, place approximately ½ C (~125 mL) of broth. Then, put the lid on loosely, set the jar in a pot of water (hopefully deep
enough to reach up to the neck of the jar, but not run over/into the top. Heat on the stove until the water is at a “rolling boil,” and
boil the jar for 5 min (start timing after the water is boiling), then let it cool to room temperature. Do not remove the lid and do not tighten it all the way, but leave it on
somewhat loosely.
- The second jar and its lid should be thoroughly hand-washed with soap and water, then dried.
Place a little more than ½ C (~125 mL) of broth in the small pot and boil it for 5 min. Let it cool just enough that
the pot is still warm but just cool enough to handle, then pour the broth into the clean jar and place the lid on loosely.
- Now, have fun designing your own conditions to test. You could try things like boiling a jar but not boiling the broth you put in it, or
boiling the broth for different amounts of time, or comparing microwaving to stove-top boiling, or leaving a jar completely open and uncovered,
or covering a jar with gauze, or stuffing a cotton ball into the neck of a bottle with a narrower neck, or tightening the lid of a jar
all the way so it “seals,” or comparing hand-washing to dishwasher-washing, etc.
Take notes on what you do (describe the set-up of each condition you test).
- Set all the jars in an out-of-the-way corner (optionally, you could place another jar in the refrigerator for a temperature comparison), and leave them there for 3 days (maybe a bit longer if your house is cool).
Check them daily and jot down any interesting things you observe.
- After three days, carefully examine the contents of each jar and record your findings. Note whether
there has been any color change or if any cloudiness has developed. Notice if any mold has obviously
started to grow in/on the broth. Notice how the smell of the broth compares to what it had been – do
any of the jars smell “bad” now?
- When you’re done observing your results, you may dispose of the broth and clean out the jars. Spend some time thinking about what your results mean.
If any of your jars of broth became smelly or cloudy what do you think caused that? How does that
relate to the type of jar covering, the cleanliness of the jar, the amount of boiling, storage temperature, or whatever else you tried?
- Additionally, research, think about, and be prepared to answer the following questions:
- Why do you think low-salt broth would be important to the outcome of the experiment?
- What is Spontaneous Generation? How does this experiment disprove the idea of Spontaneous Generation?
- The Bio 104 Introduction Web Page lists and briefly explains the following subdisciplines
within biology:
- Anatomy
- Botany
- Cytology
- Ecology
- Entomology
- Genetics
- Microbiology
- Molecular Biology
- Paleontology
- Physiology
- Zoology
For each of these branches of biology, tell what the “big words” mean (what does each branch study?).
Explain how each of these relates to your everyday life (for example, maybe zoology could relate to you having a pet).
What other branches of biology can you think of? Find 4 more (make sure they’re really biology – things like psychology, archeology, and geology don’t count),
explain what each of those branches of biology is/studies, and relate each one to your daily life.
- That Web page also has a list of properties of living organisms, including:
- precise organization
- ability to take in energy and use it
- ability to respond to stimuli
- capacity for growth and development
- ability to reproduce
- ability of a population to evolve
Relate each of those properties to humans, specifically. How do we know humans are alive?
Now, think about a volleyball. Does that exhibit any of the properties of life?
Tell how, based on those properties, you know whether a volleyball is or is not alive.
- If you are a
registered student, to receive credit for this assignment, you need to submit your work
for this project.
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o, what does a volleball picnic have to do with biology, anyway?
In short, everything! Over the course of the quarter, we’ll look at all kinds of ways the two relate, including
people who are using their muscles to play volleyball, sweating when they get hot then drinking water so they don’t get dehydrated,
eating food so they have the energy to play ball, enjoying the wild and domestic plants and animals which surround them, and
maybe even showing off a bit to gain the attention of “that special person”.
