Names: ________________________________________________________________________Date _______________
______________________________________________________________________________Period ______________
Safety Procedures
1. Conduct yourself in a responsible manner at all times in the laboratory.
2. Follow all written and verbal instructions carefully. If you do not understand a direction or part of a procedure,
ask the instructor.
3. When first entering a science room, do not touch any equipment, chemicals, or other materials in the laboratory
area until you are instructed to do so.
4. Perform only those experiments authorized by the instructor. Never do anything in the laboratory that is not
called for in the procedures or by the instructor. Carefully follow all instructions. Unauthorized experiments
are prohibited!
5. Be prepared for your work in the laboratory. Read all procedures thoroughly before entering the laboratory.
6. Horseplay, practical jokes, and pranks are dangerous and prohibited!
7. Observe good housekeeping practices. Your work areas should be kept clean and tidy at all times.
8. Keep hands away from face, eyes, mouth, and body while using preserved specimens (your frog). Wash your
hands with soap and water after performing your experiment.
9. Clean all work surfaces at the end of the experiment and return all equipment to its proper place.
10. When using knives and other sharp instrument, always carry with tips and points pointing down and away from
you and others. Always cut away from your body and others. Never try to catch falling sharp instruments.
Grasp sharp instruments only by the handle.
11. Taking any part of your specimen out of this classroom is prohibited.
I understand and agree with the safety procedures and will obey them. I am aware that any violation of this safety
contract will result in my being removed from the laboratory, detention, and/or receiving a failing grade.
I understand and agree that I will participate and help my group with this investigation by following the Lab Group
Boundaries and will be evaluated by my group members at the completion of this laboratory investigation about my
cooperation and participation:
1.
2.
3.
4.
Staying with my group at all times.
Talking about my group’s task.
Talking with the members of my group only.
Talking in a volume that can only be heard by the members of my group.
Signatures
Member 1: _________________________________________________________
Member 2: _________________________________________________________
Member 3: _________________________________________________________
Member 4: __________________________________________________________
Frog Dissection Lab
Follow all Safety Procedures at all times.
Fill in Figure 2 as you are following steps 1-9:

Observe the dorsal and ventral sides of the frog.
Dorsal (Top) side color __________________
Ventral (belly) side color _______________________
Why would there be a difference between the coloration of the sides? _________________________________
___________________________________________________________________________________________

Examine the hind legs. Label the hind legs.
How many toes are present on each foot? _____________
Are the toes webbed? ____________
What benefit would this be for the frog? __________________________________________________________
___________________________________________________________________________________________

Examine the forelegs. Label the forelegs.
How many toes are present? _______ Are the toes webbed? ___________

A. Describe the differences in the back legs and the front legs. _______________________________________
___________________________________________________________________________________________

What would be the reason for the differences? _________________________________________________
________________________________________________________________________________________

Use a ruler to measure your frog, measure from the tip of the head to the end of the frog’s backbone (do not
include the legs in your measurement). ____________________________ cm

Locate and label the frog’s eyes; the nictitating membrane is a clear membrane that attached to the bottom of
the eye. Use forceps to carefully remove the nictitating membrane. Why do you think that the frog has this
adaptation?
___________________________________________________________________________________________
___________________________________________________________________________________________

Just behind the eyes on the frog’s head is a circular structure called the tympanic membrane, label this
structure. The tympanic membrane is used for hearing. Measure the diameter (distance across the circle) of the
tympanic membrane.
Diameter of tympanic membrane ________________ cm

Feel the frog’s skin. Is it scaly or slimy? ___________________ The skin of a frog has several adaptations that
allow it to survive its environment. Use the QR codes to research information about these adaptations. List the
adaptations of the skin and what the benefits are for each: ___________________________________________
___________________________________________________________________________________________

Label the Mouth and External Nares (nostrils).

Pry the frog’s mouth open and use scissors to cut the angles of the frog’s jaws open. Cut deeply enough so that
the frog’s mouth opens wide enough to view the structures inside.

Locate and label the tongue. Does it attach to the front or to the back of the mouth? ________________
Why would the attachment location for the frog be beneficial for its survival? Check the QR Codes for answers.
___________________________________________________________________________________________

In the center of the mouth, toward the back is a single round opening. This is the esophagus, also called the
gullet in the frog. Label this structure. This tube leads to what organ? __________________________________
Use a probe to open this structure.

Close to the angles of the jaw are two openings, one on each side. These are the Eustachian tubes. Label the
tubes on the diagram above. The Eustachian tubes are used to equalize pressure in the inner ear while the frog
is swimming. Insert a probe into the Eustachian tube. To what structure does the Eustachian tube attach?
_________

Just behind the tongue, and before you reach the esophagus is a slit like opening. (You may need to use your
probe to get it to open up. This slit is the glottis, and it is the opening to the lungs. The grog breathes and
vocalizes with the glottis. Use your probe to open the glottis and compare that opening to the esophagus.
Describe any differences you see. ________________________________________________________________

The frog has two sets of teeth. The vomarine teeth are found on the roof of the mouth. There are two of these
at the front of the mouth. Label them now. The other set of teeth are called the maxillary teeth and are found
around the edge of the mouth. Label these teeth now. Use the QR Codes to determine for what purpose both
sets of teeth are used _______________________________________________________________________.
Run your finger over both sets of teeth and note the differences between them __________________________
___________________________________________________________________________________________

On the roof of the mouth, you will find the two tiny openings of the nostrils, if you put your probe into those
openings; you will find they exit on the outside of the frog. Label the internal nares now.
http://darcymoonbooks.com/?tag=top-ten-frog-adaptations
http://www.ehow.com/facts_6866466_frog-habitatadaptations.html
http://www.torontozoo.com/adoptapond/curriculum/d3_popup
1.html
http://www.sciencekids.co.nz/sciencefacts/animals/frog.html
http://www.kidzone.ws/lw/frogs/facts.htm
http://www.kiddyhouse.com/Themes/frogs/

QR Codes to help with adaptation question in this packet.
15. How many lobes does your liver have? _____________
16. Why do you think it is different from the frog? _____________________________________________________________________
Using the words below, label the structures on Figure 4 above.
Cloaca
Pancreas
Stomach
Liver
Small Intestine
Large Intestine
Gall Bladder
4. Carefully remove one lung. Insert a medicine dropper into the open end of the lung and seal
the opening with your fingers and pump air into it.
Using the words below, label the structures on Figure 5.
Right Atrium
Left Atrium
Ventricle
Heart
Lung
Kidney
Urinary Bladder
Ureter
Online Practice Tests:
Frog Test 1
http://www.biologycorner.com/frog/frogtes
t1.html
Frog Test 2
http://www.biologycorner.com/frog/frogtes
t2.html
Frog Test 3
http://www.biologycorner.com/frog/frogtes
t3.html
Frog Test 4
http://www.biologycorner.com/frog/frogtes
t4.html