External Dissection

Frog’s Name:

Surgeon:

Reader:

Recorder:

Quality Control Officer:

General Guidelines

  • When you need to weigh a frog, carry him over to the scale. (He will not hop.)
  • Don’t assume you lab partners want to touch or be touched by the frog.
  • Do not pick the frog up and put it in anyone’s face or touch them with it.
  • Follow ALL directions!
  1. Examine the skin of the frog. Notice the pattern of pigment and the pattern of spots. What is the advantage of its greenish-brown color?
  1. Feel the loose skin. What can a frog do through its skin?
  1. Look at the frog’s hind legs. How are they specialized for him?
  1. Look at the frog’s front limbs. They are different from the back legs, why?
  1. What characteristic about the frog’s head allows his body to be underwater and still breathe?
  1. What advantage does the frog have by his eyes and nostrils being on the top of his head?
  1. Where in the mouth is the tongue attached? How does that help the frog?
  1. How many volmerine teeth does the frog have?
  1. Measure the frog’s total length from nose to toe. (Gently stretch the frog out to measure.) How long?
  1. Measure the frog’s hind legs from cloaco (look it up if you don’t know) to the toes. How long?
  1. What percent of the total frog’s length are his hind legs? Hint: LL/TL = %
  1. What is the frog’s weight in grams?

Clean up procedures:

  1. Get a body bag (zip lock). Write each member’s name and the frog’s name on the tap.
  2. Wrap your frog in a paper towel.
  3. Moisten the paper towel at the front sink.
  4. Put the frog into the bag and zip it closed. Force the frog in, he/she will go.
  5. Place him/her in the plastic bin at the end of your lab station.
  6. Return all supplies to the correct container in the front of the room.
  7. Go wash your hands.