Biology Of Bc Vertebrates 3

Front 1

Amphibian evolution
-similar to..
-vertebra shape and skull
-reverse evolution
-loss of tetrapod limbs for what
-amphibian evolution with respect to timescale
-modern amphibians are grouped by.. anurans, urodela, and caecilians

Back 1

-modern salamanders, lizards and snakes
-spool-shaped vertebra and solid skull
-numerous cases of reverse evolution
- loss of limbs for burrowing and aquatic life
-amphibian diversity peaked in early permian but mostly disappeared by mid-permian until jurassic
-anurans: no tail; urodela: tailed; Caecilians: blind, legless, burrowing.

Front 2

-This study shows that extant amphibians originated in what period
- Frog and salamanders diverged when

Back 2

-late carboniferous
-early permian

Front 3

FROG VS. TOAD
-eyes, teeth, skin, charateristics

Back 3

- frog: eyes buldge, toad: eyes do not buldge
- frog:has teeth in upper jaw, toad: no teeth
- frog:moist and smooth, toad: dry and bumpy
- frog: stays in/near water, toad: stays mostly on land

Front 4

Frog life cycle stages
1.pre-metamorphosis
2. pro-metamorphosis
3. metamorphosis

Back 4

1.only external gills, tadpole just hatched
2. hindlimbs begin to appear, lungs replace internal gills
3. a conspicious, abrupt change in body structure

Front 5

what happens in metamorphosis
what is metamorphosis triggered by
frogs are most susceptible to predation when

Back 5

- forelegs develop, tail muscles/skin reabsorbed
-formation of glands, head and intestinal reorganization
- skeleton calcifies, large mouth develops
-lungs, ears, teeth and eyes develop

-thyroxine from pituitary

-transforming adults by far and transforming tadpoles

Front 6

Frogs- gas exchange
-skin, mucous function
-gas exchange of tadpoles and adults

Back 6

-skin is permeable and covered in mucous glands which secrete mucopolysaccharides(for moistness and permeability)
-frogs would overheat and die without mucous
- tadpoles: use gills and skin for gas exchange
adults: use one or more mechanisms depending on extent of metamorphosis
terrestrial use lungs primarily

Front 7

How amphibians hydrate, water loss, absorb moisture, deposit urea, recover from water lost, recover from over-hydration, and behavioural adaptation


FOUND IN MOIST FORESTS SO WATER LOSS THROUGH SKIN IS LOW

Back 7

-hydrate: they dont drink water, but they hydrate in water and dehydrate on land
-water loss- through skin on land
-water gain- pelvic patch which is very vascularized and absorbs moisture
-deposit urea- in skin which facilitates water absorption
-recover from loss- seek out moist dirt or dew during resting period to put pelvic patch
-recover from over-hydration- raise body off moist surface to increase evaporative water loss
-behavioral adaptions- nocturnal, resides underground during dry season

Front 8

DEFENSE MECHANISMS

Back 8

camouflage and aposematic coloration(warning)
mucous:antibiotic function and reduce handling by predators
poison glands
hemolytic proteins, epibatidine: blocks neurotransmitter action
neurotoxins(alkaloids): in poison dart frogs

Front 9

study showed- cutaneous glands
study 2 showed- amphibian skin secretions as source of antibiotics and bio active substances

Back 9

1. 2 types of cutaneous glands: mucous and venom
2. they show antimicrobial, anti inflammatory and even antiviral (AIDS)