amphibia

Question 1

What are some of the challenges that come with migrating to land?

Answer 1

oxygen content, environment density (less dense and less support than water), temperature variation, air is drier

Question 2

What are some characteristics of tetrapods?

Answer 2

four limbed, muscular limbs with well defined joints and digits

Question 3

What are some characteristics that were made in aquatic habitats that allowed for terrestrial exploration?

Answer 3

internal nares, air filled cavity for gas exchange, bony elements for support. Key point is that these occurred before the transition to land

Question 4

What are some characteristics of amphibians?

Answer 4

4 digits on limbs instead of 5 on most other tetrapods, life still closely tied to the aquatic environment

Question 5

What are the 3 living orders of amphibia?

Answer 5

frogs, salamanders, and caecilians

Question 6

What are some characteristics of caecilians?

Answer 6

blind as adults, limbless, internal fertilization

Question 7

What are some characteristics of salamanders and newts?

Answer 7

forelimbs and hindlimbs roughly equal size and right angled to body, carnivorous, metamorphic with aquatic larval stage and terrestrial adult stage

Question 8

What is paedomorphosis?

Answer 8

this is when the adults retain features that are common in the juvenile form

Question 9

What are the species that do not undergo any metamorphosis called?

Answer 9

perennibranchiates. in these species, the thyroid gland does not produce TSH, therefore metamorphosis does not occur. Some species, like the axolotl, stay in juvenile form but can transform under certain conditions

Question 10

Describe the integumentary system of amphibians.

Answer 10

skin is thin, wet, loosely attached. permeable to water and gases. outermost layer composed of keratinized cells and is periodically molted. thicker, spongy dermis