Highest_priority_cards_10_-_all_duplicates Flashcards
Q: Where are amphibians classified taxonomically?
Amphibians are one of the five (actually >5 because multiple fish classes) classes in the Vertebrata subphylum.
Kingdom: Animalia; Phylum: Chordata; Subphylum: Vertebrata; Class: Amphibia.
Q: What are the three living orders of Amphibians
Frogs and toads, order Anura
Salamanders and Newts, order Caudata
Caecilians, order Gymnophiona (limbless, worm/snake shaped, small/nonexistent eyes)
Q: What was the first Class of vertebrates that stepped out onto land? How long were they the only vertebrates on Earth? (Or maybe only on land? Check on this.)
Amphibians
60 M years
Q: Adaptations that allowed amphibians to stay out of the water for longer periods
lungs improved
skeletons became heavier and stronger
Q: “Disadvantages” of amphibians that kept them reliant on water
Gas-permeable skin, which serves to aid their inefficient lungs, requires moisture.
Jelly like eggs cannot survive out of water.
Q: Vertebrate
Animal with an encased nervous system including a well-developed brain and a nerve cord that runs through the (internal) spinal column or backbone.
Have a muscular system and an internal skeleton that supports and protects internal organs, provides mobility.
Highly developed nervous system; vertebrates can react very quickly to changes in their surroundings, giving them a competitive edge
Often larger and have more complex bodies than invertebrates.
The most advanced organisms on Earth.
Subphylum of the Chordata phylum
Q: Endoskeleton
an internal skeleton, such as the bony or cartilaginous skeleton of vertebrates.
Q: Advantages of an endoskeleton over exoskeleton
Endoskeleton can grow with the organism. No molting.
Provides greater flexibility in movement.
Will support greater weight without becoming too heavy for the organism.
Q: Characteristics of amphibians
Vertebrates
Ectothermic
Life cycle tied to water, with eggs and larvae found in freshwater. Require cool, moist environments for their eggs and their skin. Naked skin (it lacks fur, feathers, or scales)
Larvae have gills and adults have lungs
Most adults are insectivorous; juveniles are herbivorous
Mainly temperate and tropical species
Adults have a three-chambered heart. Tadpoles have two-chambered heart.
Note: The word amphibian comes from the Greek amphi and bios, meaning “double life”, that is, they can live or function on land and in freshwater.
Q: Ectothermic
any animal whose regulation of body temperature depends on external sources, such as sunlight or a heated rock surface.
Q: Nictitating membrane
A transparent or translucent third eyelid present in some animals (including amphibians) that can be drawn across the eye for protection and to moisten it while maintaining visibility.
Q: Amphibian eggs
gelatinous egg
similar to fish egg
no shell, deposited in water or other damp location (damp soil, on a certain plant, on mom’s back) to prevent from drying out
series of jellylike layers that protect the developing embryo from desiccation, pathogens and, to a limited extent, predators
Oxygen and carbon dioxide diffuse passively through outer membrane
Q: Metamorphosis in amphibians
All amphibians exhibit complete metamorphosis: egg, aquatic larval form w/gills, adult w/lungs.
Amphibians are the only four-limbed or land vertebrate that go through a complete metamorphosis.
Full metamorphosis averages 12-16 weeks, time span greatly affected by water temperature and food supply.
Recall a benefit of metamorphosis: adults and young fill different niches and don’t compete.
Q: One way amphibians are important to ecosystems
Crucial role in food web, especially as predators and as prey for other animals.
Loss of amphibians would result in disastrous ecosystem-wide effects in terrestrial and aquatic environments.
Q: Threats to amphibians
Pesticide runoff from farms, pharmaceuticals flushed down the toilet have contributed to defects and mutations such as multiple or deformed legs.
Chytridiomycosis (or chytrid fungus)- fatal disease affecting amphibian populations worldwide; has caused decline or extinction of many species.
Invasive, introduced species out-compete native species to the point of extinction. Marine toad introduced to Australia from Hawaii; prolific breeder; steadily increased its range.