Name _______________________________________ Date ______________
Gen Bio 2 Lab #9: Amphibians, Reptiles, and Birds, oh my…
1. Endothermic –
2. Ectothermic –
3. Fat bodies –
4. Cloaca –
5. Atrium –
6. Ventricle –
7. 3-chambered heart –
8. 4-chambered heart –
9. Pulmonary circuit –
Procedure 1 Bird Skeleton – Observe the bird skeleton and note the bones of the wings and position of
the pectoral and pelvic girdles. Write 2 sentences about your observations.
Procedure 2 Bird X-rays – Observe the X-Rays of birds. How do they compare to one another? What
differences do you notice?
Procedure 3 Preserved Birds- Observe the preserved bird specimens. Record any thoughts or
Procedure 4 Birds’ nests – What does the structure of the 2 bird nests say about these birds and
Procedure 5 Preserved Reptiles – Observe the preserved specimens of Reptiles. How many of these
have you seen in the wild? Which reptiles do you find most interesting/gross/cool, and why?
Procedure 6 Reptile X-Rays – Observe the X-rays of several reptiles. Note the internal skeleton of the
1) Why does a turtle have bones and an exoskeleton?
2) What do the baby turtle eggs in the X-ray look like?
3) Can you see the dwarf crocodiles in the egg X-ray? What developmental stage are these
Procedure 7 Frog X-Ray – Observe the X-ray of the frog. Record any thoughts or observations.
Procedure 8 Preserved Frogs – Observe the preserved frogs. Record any thoughts or observations.
Procedure 9 Frog Poster – Look at the cool 3D frog poster. Record any thoughts or observations.
Procedure 10: Frog Dissection—Follow the Directions below to complete your frog dissection. Be sure
to answer all the questions.
Self-Guided Frog Dissection
• Describe the appearance of various organs found in the frog.
• Name the organs that make up various systems of the frog.
• preserved frog
• dissecting pins (6–10)
• dissecting tray and paper towels
• plastic storage bag
• marking pen
• dissecting needle
1. Put on gloves.
2. Place a frog on a dissection tray. To determine the frog’s sex, look at the hand digits, or fingers,
on its forelegs. A male frog usually has thick pads on its "thumbs," which is one external
difference between the sexes, as shown in the diagram below. Male frogs are also usually smaller
than female frogs. Observe several frogs to see the difference between males and females.
What is the sex of your frog specimen? _____________
3. Use the diagram below to locate and identify the external features of the head on your dissection
specimen: mouth, external nares, tympani, eyes, and nictitating membranes.
4. Turn the frog on its back (dorsal surface) and pin down the legs. Cut the hinges of the mouth and
open it wide. Use the diagram below to locate and identify the structures inside the mouth. Use a
probe to help find each part: the vomerine teeth, the maxillary teeth, the internal nares, the
tongue, the openings to the Eustachian tubes, the esophagus, the pharynx, and the slit-like
5. Look for the opening to the frog’s cloaca, located between the hind legs. Use forceps to lift the
skin and use scissors to cut along the center of the body from the cloaca to the lip. Turn back the
skin, cut toward the side at each leg, and pin the skin flat. The diagram above shows how to make
6. Lift and cut through the muscles and breast bone to open up the body cavity. If your frog is a
female, the abdominal cavity may be filled with dark-colored eggs. If so, remove the eggs on
one side so you can see the organs underlying them.