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Period 2


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									Name _________________________________ Date ________________ Period ______

Lesson 16 - Daphnia

1. Daphnia are related to lobster and shrimp. When you observe a Daphnia, what characteristics do
you expect them to have?
Big black eyes, antennas, pinkish color, exoskeleton, claws

Lab Procedure:
a. Observe the Daphnia under the highest setting that would allow you to see the entire organism.
b. Draw the Daphnia. Title the drawing Daphnia, measure the size and note it next to the title.
c. Label the legs, intestine, heart, brood chamber, eye, carapace, and antenna – use p. 193 in the
OMM book to help you label the drawing.



                                1   2   3   4   5   6   7   8   9   10

2a. What kind of skeleton do Daphnia, lobsters and shrimp have? exoskeleton

2b. What are the advantages and disadvantages of this type of skeleton over the type of skeletons
humans have?
Advantage – protection from predators and environment, more strength to carry material
Disadvantages – slower to move maybe?, breakage is harder to heal/fix, limits growth

3. What do you think is inside the brood chamber of the Daphnia? eggs

4. How does the Daphnia’s eye differ from the human eye? Compound eyes
Effects of Cola and Alcohol on heart rate
Problem: How will alcohol and cola affect the heart rate of the Daphnia?

Hypothesis: (Format: If ___________ then_________ because ____________)

Cola: If the daphnia have cola, then the heart rate will _______

Alcohol: If the daphnia have alcohol, then the heart rate will _______because


                     Number of beats per 10 seconds
                     Trial 1           Trial 2              Trial 3              Average
Water - cola         37                34                   34                   35
Water - alcohol      36                37                                        36.5
Cola                 41                Dead (up then        37                   39
                                       down and dead)
Alcohol              32                35                                        33.5

5. What are the manipulated variables? Cola and alcohol (two labs)

6. Why did we measure the heart rate of the Daphnia in spring water first? To know what the
“normal” heart rate for the daphnia is before giving it caffeine and alcohol

Conclusion: RAPPS (you need to write a 5 sentence conclusion for only one- alcohol or cola
Format for writing a CONCLUSION

R: Restate the question
A: Address your hypothesis
       (Was it supported or not supported?)
P: Provide data for evidence (high and low data)
P: Provide explanatory data (explain your data)
S: State your conclusion






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