NAME(S): ________________
BIOLOGY
THE ANATOMY
OF
DATE: _________
LAB DISSECTION
A FROG
Introduction: Frogs are typical amphibians, adapted to life in water and on land. The
organization of a frog’s internal organs is similar to the internal organization of other
vertebrates that live on land. Its smaller size makes it easy for us to study and allows us
to learn more about the higher vertebrates, like humans. In this investigation, you will
dissect the adult frog and observe structures that make the frog adapted to its
environment.
Question: What are some of the features of a frog’s anatomy that have allowed it to
survive in and adapt to its environment?
Pre-Lab Questions: Read the entire dissection handout first. Then, with your partner,
answer the following questions using full sentences. You may also need to use the class
text or the Frog Dissection Guide (on the lab tables).
1. What is the exact species name of the frog you will be dissecting?
2. What will you examine in Part A of the dissection?
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3. Why is it important to only make shallow cuts when examining the skin around the
frog’s hindlimb?
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4. After you have exposed the internal organs in Part B, what two structures might you
need to remove in order to examine the organs?
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5. Which organs of the digestive system will you identify in Part C
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6. Without the presence of eggs, how will you know whether your frog is male or female?
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7. What are the external nares?
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7. What are the defining characteristics (shared derived characters) of amphibians like
the frog?
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Materials:
 Preserved frog
 Dissection tray
 Dissection tools (including pins)
 Lab aprons, goggles, and gloves
Analysis & Conclusion:
1. Identify three function of a frog’s cloaca.
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2. Explain how the length of the small intestine relates to its function in absorbing
nutrients.
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3. Explain how the frog’s hindlimbs are adapted for life in both the land and the water.
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4. Describe a situation in which the location of the frog’s external nares would be an
advantage in breathing.
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5. Infer how the attachment of the frog’s tongue helps it to catch prey.
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6. What is the spleen used for?
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7. What is bile? Where is it produced? Stored? Used?
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8. Why is the pancreas considered an accessory organ? What is it used for?
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Lab Extension Question:
Bioethics: In a recent online survey conducted by helium.com, 52% of readers wanted to
ban high school dissection, and 48% of readers did NOT want to ban dissections. On a
separate sheet of paper, describe three reasons to ban dissection, and three reasons to
continue dissection. Then write your own opinion.
This lab should by typed in your lab binder. It is due on: _____________.
It will include:
Figure 6: Circulatory, Digestive, and Respiratory Systems
Figure 7: Reproductive and Excretory Systems