NAME: ________________________________ FROG DISSECTION PRE-LAB
FROG PRE-LAB TUTORIAL part 1- WITH QUESTIONS LABELED WITH LETTERS OF ALPHABET.
1. Go to the following site: http://www.mhhe.com/biosci/genbio/virtual_labs/BL_16/BL_16.html
2. Put in your earbuds for sound! Click on introduction. Listen to the introduction.
3. Click on next after listening to the verbal introduction. Listen to information.
4. Click on next. Click on Play button for the videoclip. You may also have to click on the Right
arrows.
5. Record answers to these questions.
A. What type of frog is this?
B. What are possible colors of this frog?
C. What phylum and subphylum does the frog (& human) belong to? Cick on next.
D. How many classes of vertebrates are there? What are they?
E. What class are frogs in?
F. What does amphibian mean?
G. What are 3 things that frogs use during their life to help them breathe?
H. What are the stages of metamorphosis? What do they lose as they become adult?
I. What do most adult frogs eat? Click on next.
J. How large are most leopard frogs? Where do we find them? Click on next. Click on play arrow.
K. What tools are needed for dissection? Click on MENU. Click on External Anatomy.
L. What is the dorsal side? The other side is called what? What is it called when it helps it blend into
the surroundings? Click on next.
M. What does anterior mean? posterior? head? torso? dorsal? ventral? Click on next.
N. Describe the skin. What helps keep the skin moist? What function does the skin help with?
13. Click on next. Click on Play button. You may need to click on the double arrows to start.
O. What passes into the skin? What passes out of the skin? Click on next.
P. Why are the location of the eyes important? What are nostrils for?
Q. What are tympanic membranes? Click on next.
R. What is the opening for eggs/sperms or wastes called? Click on next.
S. How many toes does each forelimb have? (Click on next and play and maybe double arrows.)
T. How many toes are in the hindlimbs? What is different about their toes? What are hindlimbs used
for? Click on Menu. Click on internal anatomy. Click on Play.
U. How should you place your frog in the dissection pan?
V. What do you use to hold frog in dissection pan?
W. How many cuts will be needed to open the frog? (Note where these are.)
X. What lies directly below the skin? Click on next. click on next. Click on scissors. Click on next.
14. Follow all procedures to prepare your cuts using appropriate tools to help you until you reach the
digestive system tab. Click on play to see how to cut jaw.
Y. What are the 3 different types of openings? What are the teeth called? Click on next.
Z. What is the largest organ? What is bile for?
AA.
Name organs found in this area of digestive system and other organs in this area.
22. Click on next. Follow directions for removing organs and using appropriate tools. After intestines
are removed, click on next.
BB. What is different in frogs that humans do not have in the respiratory system? Click on next.
CC. Air goes into the nostrils which leads to what 4 areas? (Click on next.)
DD. What are the sac-like structures? What gases will be exchanged here? (click on next.) Click on
play. Click on next.
EE. What acts as a pump? Click on next.
FF. What are the smallest blood vessels? (Click on next?)
GG.
What are the largest blood vessels that carry blood away from the heart? What are the
vessels that carry blood toward the heart? (These are middle size.) Click on next.
NAME: ________________________________ FROG DISSECTION PRE-LAB
HH. How many chambers are in the frog? What is the pumping portion called? How many
chambers do we have? click on next.... click on play to see inside heart.
II. Where does oxygen poor-blood come in from? Why isn’t this heart as efficient as birds and
mammals? What else benefits the frog that birds and mammals cannot use for respiration to help
in circulation? click on next.
JJ. Males form sex cells (sperm) where? Females produce eggs where? What are the yellow bodies
called? click on next...
KK. What shape are testes? Where do they lead to? click on next..
LL. What is the oviduct? Where are the eggs fertilized?
MM.
In the excretory system, what organs help filter blood of unwanted wastes? click on next...
listen and click on next again.
NN. What is the long tubes that lead wastes to the urinary bladder called? click on next
OO.
What is the urinary bladder? click on next...
PP. Where do waste leave? click on next to view nervous system.
QQ.
What are the major parts of the nervous system? click on next... Click on play to see skull.
Watch. Click on next.. click play to see parts of brain.
RR. What do olfactory lobes control? What do the optic lobes control? click next...
SS. What is the main system of the nervous system? What does it connect directly to? click next...
TT. What 2 Sense organs are shown. How do ears compare to humans? click next...
UU. What are muscles used for? click on next. click on play to see muscle groups of legs... watch
and click on next... watch and click on next... click on play to see skeletal system.
VV. What are the 2 regions of the skeletal system? How many bones do each contain and give at
least 2 examples from each?
You are done with Tutorial #1...
PART 2
Go to the following website:
http://biog-101-104.bio.cornell.edu/Biog101_104/tutorials/frog.html
Identify all of the parts with numbers and labels for each picture below; for example, click on “internal
organ overview” and then click on each number to identify the parts. Record the label of the picture
and the numbers and correct identification for all pictures shown. There are some that have no labels
required.
COMPLETE ALL 5 OF THESE TESTS UNTIL YOU CAN GET THEM ALL CORRECT.
TESTS - online for FROG Dissection perfect... Show scores to sign off on...
http://www.biologycorner.com/frog/review.html - with other links...
Frog Test #1 - http://www.biologycorner.com/frog/frogtest1.html
Frog Test #2 - http://www.biologycorner.com/frog/frogtest2.html
Frog Test #3 - http://www.biologycorner.com/frog/frogtest3.html
Frog Test #4 - http://www.biologycorner.com/frog/frogtest4.html
Take this quiz: http://biology.about.com/od/gamesandquizzes/a/aa060107a.htm
TEST - Look at the following site to see if you can identify the following parts. You will be tested on
this after the dissection lab.
http://www.ofsd.k12.wi.us/science/test.htm
If you cannot identify all of thee parts, view the following site and see pictures with identification.
http://www.ofsd.k12.wi.us/science/frogdiss.htm
Select the areas you need to study or view: “Start the virtual frog dissection” or click on “external
frog” or “internal frog” to view parts.
NAME: ________________________________ FROG DISSECTION PRE-LAB
View the following site to help identify parts before starting dissection.
http://biocorner.cabanova.com/ Use this site during dissection to help identify parts as well.
USE THESE SITE TO START REAL DISSECTION AND TO ASSIST IN IDENTIFYING PARTS.
OPEN ALL SITES AS TABS AND GO BACK AND FORTH AS NEEDED.
Go to this site for a quick overview of what you are about to start doing. Follow directions.
Quick Glance of Frog Dissection major parts for quick review on the actual dissection day...
http://mariemarie0000.free.fr/fichiers/images/frog.swf
Follow dissection instructions of handout sheet and complete as you go using the following computer
references. One partner should be the instructor and computer operator and the other person should
be the surgeon who will not touch the computer during the dissection.
START HERE:
http://www.aa.psu.edu/biology/frog/default.htm
Click on external anatomy. Find these items on your frog and then click on next and continue. Click
on next parts as you go through instructions...
OTHER REFERENCES:
ALSO OPEN TABS FOR THESE to help identify parts.
http://biocorner.cabanova.com/
http://www.ofsd.k12.wi.us/science/frogdiss.htm
http://www.biologycorner.com/frog/review.html
http://www.casc.cc.ok.us/dwann/Frog.htm
NOTE to me - print this from original page... some format were changed...
Dissection Instructions
1. Place the frog in the dissecting pan ventral side up.
2. Use scissors to life the abdominal muscles away from the body cavity. Cut along the midline of the body from the
pelvic to the pectoral girdle.
3. Make transverse (horizontal) cuts near the arms and legs.
4. Life the flaps of the body wall and pin back.
*If your specimen is a female, the body may be filled with eggs and an enlarged ovary. You may need to remove these
eggs to view the organs.
Locate each of the organs below. Check the box to indicate that you found the
organs.
NAME: ________________________________ FROG DISSECTION PRE-LAB
Fat Bodies --Spaghetti shaped structures that have a bright orange or yellow color, if you have a
particularly fat frog, these fat bodies may need to be removed to see the other structures. Usually
they are located just on the inside of the abdominal wall.
Peritoneum - A spider web like membrane that covers many of the organs, you may have to carefully
pick it off to get a clear view
Liver--The largest structure of the the body cavity. This brown colored organ is composed of three
parts, or lobes. The right lobe, the left anterior lobe, and the left posterior lobe. The liver is not
primarily an organ of digestion, it does secrete a digestive juice called bile. Bile is needed for the
proper digestion of fats.
Heart - at the top of the liver, the heart is a triangular structure. The left and right atrium can be
found at the top of the heart. A single ventricle located at the bottom of the heart. The large vessel
extending out from the heart is the conus arteriosis.
Lungs - Locate the lungs by looking underneath and behind the heart and liver. They are two spongy
organs.
Gall bladder--Lift the lobes of the liver, there will be a small green sac under the liver.
gall bladder, which stores bile. (hint: it kind of looks like a booger)
This is the
NAME: ________________________________ FROG DISSECTION PRE-LAB
Stomach--Curving from underneath the liver is the stomach.
The stomach is the first major site of
chemical digestion. Frogs swallow their meals whole. Follow the stomach to where it turns into the
small intestine. The pyloric sphincter valve regulates the exit of digested food from the stomach to
the small intestine.
Small Intestine--Leading from the stomach.
The first straight portion of the small intestine is
called the duodenum, the curled portion is the ileum. The ileum is held together by a membrane
called the mesentery. Note the blood vessels running through the mesentery, they will carry
absorbed nutrients away from the intestine. Absorption of digested nutrients occurs in the small
intestine.
Large Intestine--As you follow the small intestine down, it will widen into the large intestine.
The large intestine is also known as the cloaca in the frog. The cloaca is the last stop before wastes,
sperm, or urine exit the frog's body. (The word "cloaca" means sewer)
Spleen--Return to the folds of the mesentery, this dark red spherical object
serves as a holding area for blood.
Esophagus--Return to the stomach and follow it upward, where it gets smaller is the beginning of
the esophagus. The esophagus is the tube that leads from the frogs mouth to the stomach. Open
the frogs mouth and find the esophagus, poke your probe into it and see where it leads.
STOP! If you have not located each of the organs above, do not continue on to the next sections!
Removal of the Stomach: Cut the stomach out of the frog and open it up. You may find what
remains of the frog's last meal in there. Look at the texture of the stomach on the inside.
What did you find in the stomach?
Measuring the Small intestine: Remove the small intestine from the body cavity and carefully
separate the mesentery from it. Stretch the small intestine out and measure it. Now measure your
frog. Record the measurements below in centimeters.
Frog length: _______ cm
Intestine length ________ cm
Urogenital System - The frog's reproductive and excretory system is combined into one system called the
urogenital system. You will need to know the structures for both the male and female frog,
Kidneys - flattened bean shaped organs located at the lower back of the frog, near the spine. They are often a
dark color. The kidneys filter wastes from the blood.
NAME: ________________________________ FROG DISSECTION PRE-LAB
Testes - in male frogs, these organs are located at the top of the kidneys, they are pale colored and roundish.
Oviducts - females do not have testes, though you may see a curly-q type structure around the outside of the
kidney, these are the oviducts. Oviducts are where eggs are produced. Males can have structures that look
similar, but serve no actual purpose. In males, they are called vestigial oviducts.
Bladder - An empty sac located at the lowest part of the body cavity. The bladder stores urine.
Cloaca - mentioned again as part of the urogenital system - urine, sperm and eggs exit here.
Label the parts of the urogenital system below.
NAME: ________________________________ FROG DISSECTION PRE-LAB
NAME: ________________________________ FROG DISSECTION PRE-LAB
Post Lab Questions
NAME: ________________________________ FROG DISSECTION PRE-LAB
1. The membrane holds the coils of the small intestine together: ________________
2. This organ is found under the liver, it stores bile: ______________________
3. Name the 3 lobes of the liver: ____________, _______________, ______________
4. The organ that is the first major site of chemical digestion: ____________________
5. Eggs, sperm, urine and wastes all empty into this structure: ___________________
6. The small intestine leads to the: ____________________
7. The esophagus leads to the: _______________________
8. Yellowish structures that serve as an energy reserve: ____________________
9. The first part of the small intestine(straight part): _______________________
10. After food passes through the stomach it enters the: ____________________
11. A spiderweb like membrane that covers the organs: ______________________
12. Regulates the exit of partially digested food from the stomach: ________________
13. The large intestine leads to the __________________
14. Organ found within the mesentery that stores blood: _____________________
15. The largest organ in the body cavity: _____________________
Label the Diagram
A. __________________________________
B. __________________________________
C. __________________________________
D. __________________________________
E. __________________________________
F. __________________________________
G. __________________________________
H. __________________________________
I. __________________________________
J. __________________________________
K. __________________________________
L. __________________________________
M. __________________________________
N. __________________________________
NAME: ________________________________ FROG DISSECTION PRE-LAB