SNC 2D Frog Dissection Lab Activity
Purpose:
The purpose of this lab is to observe the internal structures (cells, tissues, organs, and organ systems) of a frog’s
anatomy, and to determine the function of the internal structure.
Materials:



Preserved Frog
 Dissection tray
Dissecting pins
 Gloves
Dissection kits (scissors, scalpel, forceps, probes)


Safety glasses
Magnifying glasses
Procedure:
Part 1:
1. Collect your frog specimen and then rinse in water.
2. Place the frog on its dorsal side (back) and pin its limbs to the tray using 4 pins.
3. Complete the following incisions on the ventral side of the frog (as seen on the diagram below). Use the forceps
to lift the skin and use the scalpel to cut through the skin. BE CAREFUL TO ONLY
CUT THE SKIN
4. Use the forceps to pull back the skin and use the scalpel to help separate the skin
from the muscle. Pin the skin flaps to the tray.
RECORD THE APPEARANCE OF THE MUSCLES; CAN YOU IDENTIFY DIFFERENT
MUSCLE GROUPS
Part 2:
5. Repeat the three incisions you made in step 3, but this time you need to
cut through the muscle and bone layers.
Figure 1: Diagram showing
a) Use the dissection scissors to cut through the muscles. Be careful to
initial incisions for dissecting a
only cut the muscle and not the organs underneath.
frog. (Magnification 0.3x)
b) Separate the muscle flaps from the organs using the forceps and
scalpel (similar to the process with the skin). Pin the muscle back with the skin flaps. YOU SHOULD BE ABLE
TO SEE ALL OF THE INTERNAL ORGANS AFTER YOU PIN BACK THE MUSCLES
c) Use the dissection scissors to cut through the bones of the chest. When you reach the front legs, turn the
scissors sideways so that you only cut through the bones. REMOVE ANY BONE LAYERS FROM THE CHEST SO
THAT YOU CAN SEE ALL OF THE ORGANS UNDERNEATH
Diagram 1:
6. On blank paper, draw a diagram of the ventral side of the frog, labelling the liver, heart, stomach and
pancreas.
7. Use the forceps and probes to hold up the liver and heart, moving them to the side. Use the labelled Figures 2
and 3 to help locate the remaining organs of the respiratory and circulatory systems:
a) Artery
e) Liver
i) Stomach
b) Right Atrium
f) Gall Bladder
j) Esophagus
c) Left Atrium
g) Large Intestine
k) Pancreas
d) Ventricle
h) Small Intestine
Figure 2: Diagram showing internal
digestive and respiratory organs.
(Magnification 0.3x)
Figure 3: Diagram showing internal organ
systems of the frog. (Magnification 0.3x)
Diagram 2:
8. On a second piece of paper, draw a diagram of the organs of the Ventral view of the circulatory system of the
frog.
Diagram 3:
9. On a third piece of paper, draw a diagram of the organs of the Ventral view of the respiratory and digestive
systems of the frog.
10. After you have completed your dissection, dispose of your specimen as instructed by the teacher.
11. Rinse and clean all equipment, returning to the proper location.
For all diagrams:
 use a blank piece of paper and a pencil.
 have one diagram per page and draw to the same size as your specimen.
 label each diagram using straight lines.
 place a figure number and a descriptive title below each diagram
Conclusion:
1. Complete a table to describe the appearance and function of each of the following organs: pancreas, liver, gall
bladder, heart, and lungs. (K/U)
2. Frogs eat insects. Create a flowchart that shows the organs that the fly will move through as it moves through the
digestive system, from mouth to anus. (K/U)
3. You are a researcher, studying the health of frogs in a lake environment. You notice that many frogs are being found
with abnormalities in the structure of its legs, heart and lungs. Explain and describe which types of medical imaging
technologies you might select to try to screen living frogs to examine those specific organs. (A)
SNC 2D Frog Dissection Rubric
Criteria
K/U
Conclusion
Questions
1, 2
Diagrams:
T/I
Required
components
Diagrams,
C
A
labelling,
and titles
Conclusion
Question 3
Level 1
Level 2
Level 3
Name: ____________________
Level 4
Limited completion of chart
describing organs.
Includes a limited attempt
to organize the digestive
system.
Includes diagrams that are
not complete, missing
some detail.
Some completion of chart
describing organs.
Includes an attempt to
organize the digestive
system.
Includes diagrams that are
nearly complete, with
almost all details.
Good completion of chart
describing organs.
Includes a good attempt to
organize the digestive
system.
Includes diagrams that are
complete, with good detail.
Thorough completion of
chart describing organs.
Includes a detailed,
accurate organization of
the digestive system.
Includes diagrams that are
complete, with high
attention to detail.
Poor attempt at creating
titles, with improper and
incomplete labelling.
Adequate attempt at
creating titles, with
acceptable labelling.
Successful attempt at
creating titles, with good
labelling.
Excellent attempt at
creating titles, with flawless
labelling.
More reflection needed to
explain the use of medical
imaging technology.
Acceptable attempt to
explain the use of medical
imaging technology.
Competently explains the
use of medical imaging
technology.
Insightfully explains the use
of medical imaging
technology.