Exam 2 Tetrapods/Amphibians

1. How where early tetrapods, "fishapods" as they are sometimes called, pre-adapted for the transition to land?

Acanthostega had internal gills but not fully terrestrial

Discuss reproduction and parental care in amphibians. In your answer be sure to use specific examples.

Aquatic development: eggs deposited in water devloped in water Semiterrestrial development: eggs " out of water Terrestrial development: eggs & young independent of standing water

Outline the evolution of tetrapods. Who were the major players (what species) and what anatomical changes do we see in each

Eusthenopteron (nostrils, lobe fins) Panderichthyes( Ossified vertebrae) Elpistostege( eyes top of head, arm bones) tiktaalik ( ribs loose operculum) acanthostega (gills ribs) ichthyostega ( flexible spine, Polydactyl digits)

What are the three main Orders of amphibians and the defining features of each?

Frogs and toads (Anura) short and tailless Salamanders (Caudata) presence of tail, and ribs Caecilians (Apoda) legless, venom

Discuss respiration and circulation in amphibians, how is it different from fish?

amphibians use buccal pumping, and double circuit fish use gills

What are the distinguishing characteristics and major groups of lobe-finned fish?

colecanthamorpha= 3 lobbed tsil, ossified swim bladder Dipnoi= internal nares osteolepimorpha= long mouth lined with strong teeth tetrapoda= presence of digits in forelimbs, and hindlimbs

What are the main characteristics of amphibians?

countaneous respiration, moist skin (permeable to gases h2o), granular glands( posion secreation)

List and explain the reasons for amphibian decline

habitat loss pathogens global climate change pesticides

What physiological and morphological adaptations were necessary for life on land?

nervous system, organ system, respiratory sytem, appendages, body structure,

Discuss the pros and cons of moving from water to land. What are the major hypotheses about this transition

pros: new food resources , Avoid predators/competition, oxygen cons: temperature, gravity(need support), water limiting factors

Discuss amphibian skin. What functions does it play in the life of a typical amphibian? In your answer be sure to mention specific examples.

they have smooth moist skin that is permeable h20 n gas. it helps with breathing, and thermoregulation