Name: ____________________ Date: ___________________ Class: _____________Virtual Lab: Virtual Frog Dissection

Part I: Lab Report

1. If you come upon any terms that are unfamiliar to you, please refer to your

textbook for further explanation or search the word here:

http://www.mhhe.com/biosci/genbio/virtual_labs/BL_16/BL_16.html. In this

exercise, you will be performing a virtual frog dissection. To begin, click on

the “Introduction” link on the opening page. Read through and listen to the

information presented to learn about the basics of dissection and animal

phylogeny

2. Once you are back to the opening page, click the “External Anatomy” button.

Read through, watch and listen to the information presented in these

segments. When you are finished, click the “Menu” button at the bottom of

the page to return to the opening page of the laboratory activity.

3. The last portion of this activity involves an examination of the internal

anatomy of a frog. To do this, click the “Internal Anatomy” button on the

opening page of the laboratory. Read through, watch and listen to all of the

information presented in these segments and actively participate where

required. You may have to do a virtual cut on the frog by dragging the

appropriate tool to the frog or label organs of the dissected frog by dragging

the appropriate organ names to the site on the opened frog. Please STOP

when you are through with each labeling step and be sure to fill in your final

answers on Figures 1 and 2 below.

4. When you are through opening all of the segments in the “Internal Anatomy”

section, you will have successfully completed the virtual dissection.

Virtual Lab Questions

A. Introduction

a. Natural History:

i. Define Dorsal: ___________

ii. What phylum are frogs in? ________________

iii. What subphylum? ____________________

iv. Define vertebrate:

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b. Dissection Tools

i. List the dissection tools used in a frog dissection

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B. External Anatomy

a. Introduction

i. What are the possible colors of the dorsal side of a frog?

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ii. What is the underbelly of the frog called? ___________

iii. Name the five main parts of the frog:

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b. Skin

i. Why is the frog’s skin slippery?

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ii. What does skin aid in? How is this different from humans?

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iii. List two reasons why there is mucus coating the frog’s

skin:

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c. Head

i. Why is the location of the frog’s eyes important?

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ii. What is the tympanic membrane for?

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iii. Trace the path of sound in the frog

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d. Cloaca

i. What three substances can be discharged from the cloaca?

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ii. Where is the cloaca located?

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e. Legs

i. Compare the frog’s forelimbs to the frog’s hind limbs:

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ii. How many digits (toes) does each forelimb have? _______

C. Internal Anatomy

a. ** Initial Cut

i. How should the frog be placed when dissected?

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ii. Where should the pins be placed in order to hold the frog

down?

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iii. How should the pins be inserted? ____________________

iv. On the frog below, indicate the placement of the five

initial incisions?

v. The first cut should only be through the _______________

vi. After the skin is cut, stabilize the skin with __________

vii. Why is the skin part of the respiratory system?

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viii. Why is the muscle tissue cut?

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ix. Where is the muscle tissue cut?

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x. After the muscle is cute, stabilize with __________

b. **Digestive System

i. Why is the jaw cut?

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ii. Where is the jaw cut?

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iii. Name the two openings you see inside the frogs mouth.

Where is each located? What system do each involve?

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iv. What are the tooth-like structures in the frogs mouth

called? ______________________________

v. Where are these structures located?

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vi. Label the organs of the digestive tract below (Liver,

stomach, gallbladder, pancreas, small intestine, pancreas,

large intestine, cloaca)

vii. Describe the size and structure of the liver:

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viii. What is the purpose of the liver?

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ix. What occurs in the stomach for the first time and what

two digestive organs does it connect?

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x. What is the purpose of the gallbladder?

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xi. What is the purpose of the pancreas?

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xii. What is the purpose of the small intestine?

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xiii. What is the purpose of the cloaca?

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xiv. In the lab, the liver, stomach, pancreas and intestines will

be removed. Locate each organ and indicate the incisions

for this extraction on the diagram below.

c. Respiratory System

i. What two organs are involved in the respiratory system of

the frog?

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ii. Trace the path of air from the atmosphere to the frogs

lungs:

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iii. How many lungs do amphibians have? ________________

d. **Circulatory System

i. What is the purpose of heart? The vessels?

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ii. What is the smallest vessel:________________________

iii. What vessels do capillaries connect? _________________

iv. What is the purpose of arteries? Of veins?

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v. Describe the structure of the frog’s heart.

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vi. How does it differ from the human heart?

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e. **Reproductive System

i. What is formed in testes? In ovaries?

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ii. What is the purpose of fat bodies?

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iii. Describe the structure of the testes:

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iv. Describe the structure of the ova:

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v. Trace the path of the egg from ova to fertilization:

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f. Excretory

i. What is the purpose of the kidneys?

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ii. Define ureters:

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iii.

iv. Where does the waste from the kidneys exit from?

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g. Nervous

i. What are the three main parts of the nervous system?

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ii. What two parts are the brain separated into?

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iii. What is the olfactory lobe responsible for?

_______________________________________________

iv. What part of the brain is located behind the olfactory lobe:

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v. What are the optic nerves responsible for? ____________

vi. When dissecting to see the brain, where are the cuts

made? Indicate on the diagram below:

vii. How is the skull removed to access the brain?

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h. Muscular

i. The muscles are attached to ________________ and

responsible for ______________.

ii. What muscles will be viewed in the lab?______________

The incision should be made according to diagram below

iii. Once the incision is made, list all instructions to get to the

muscle:

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iv. The muscles of the frog are organized in _______________

v. What do the muscles in the upper leg move? ___________

vi. What do the muscles in the lower leg move? ___________

i. Skeletal

i. What two regions does the skeletal region include:

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ii. Where each of these regions located?

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iii. How many bones does each region contain? Name one

bone in each region:

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