Frog dissection

Question 1

what frog species did we dissect?

Answer 1

American bull frog, Rana catesbeiana

Question 2

how does frog skin allow for cutaneous respiration?

Answer 2

it is thin and vascular (many veins)

contains mucus secreting glands

Question 3

What are the tympani?

Answer 3

dermal folds on either side of the face behind each eye
these cover their ears

Question 4

How can you externally distinguish a male bullfrog from a female?

Answer 4

males have larger tympanic membranes (larger than their eyes) than females

Question 5

what do bull frogs eat?

Answer 5

anything they can fit into their mouths - fish, insects, mice, birds, snakes, other frogs

Question 6

how long do bull frogs live?

Answer 6

~7-9 years

Question 7

How many eggs can a female bullfrogs lay?

Answer 7

~20,000 eggs

Question 8

Are male or female bullfrogs larger?

Answer 8

females

Question 9

What is unique about frog tongues?

Answer 9

they’re connected at the anterior end of their mouths, rather than the posterior end

Question 10

Describe frog teeth

Answer 10

a continuous row of tiny teeth on the maxilla and premaxilla and a small pair of vomerine teeth on the palate

Question 11

What and where are vomerine teeth?

Answer 11

tiny teeth in pairs that frogs have on their palates

Question 12

are teeth present on the upper or lower or both jaws ?

Answer 12

just upper

Question 13

How does air enter the lungs?

Answer 13

via glottis

Question 14

How many liver lobes?

Answer 14

3

Question 15

How many heart chambers?

Answer 15

3

2 atria, 1 ventricle

Question 16

How does the heart and circulatory system in frogs compare to that of a fish?

Question 17

How does gas exchange vary between frogs and fish?

Answer 17

frogs have large lungs (use positive pressure breathing) and they can conduct gas exchange across their skin and mouth lining

whereas, fish conduct gas exchange across their gills

Question 18

How does waste removal vary between frogs and fish?

Answer 18

freshwater fish excrete large quantities of diluted urine

Question 19

How does reproduction vary between frogs and fish?

Answer 19

both usually lay eggs in water
many species for both have external fertilization, some in both do internal

Question 20

How do frogs deal with the challenges (ex. osmoregulation) and advantages in aquatic environments? how does this compare to how fish do it?