Transcript Frog notes
Phylum Chordata Subphylum Vertebrata Class Amphibia •Examples – Salamanders, frogs, newts •Habitat – Aquatic when young, land & water as adults •Symmetry – bilateral •Body plan – tube-within-a-tube •Coelomates •No segmentation •Organ level of organization Metamorphosis – body changes form Larva – tadpole •Breathe with gills •Fins for swimming •Fish-like circulatory system Adult •Breathe with lungs •Lose tail and develop legs •More advanced circulatory system Frog metamorphosis Protection from predators: •Skin covered in mucus – keeps moisture in; slippery to predators •Skin loosely attached – predators can’t grip them •Camouflage •Some are poisonous – brightly colored to warn predators Life Processes •Support: •Backbone and skeleton made of cartilage •No ribs to protect internal organs •Movement: •Muscles; large hind legs specialized for jumping •Feeding and digestion: •Diet – carnivores •Process: •Capturing food – tongue attaches at the front of the mouth; 2 sets of teeth to hold onto prey •Swallowing food – close eyes and push them down against roof of mouth •Drinking water – they don’t – they absorb water through their skin •Digestion continued: •Esophagus – moves food to stomach •Stomach – stores food; digests protein •Small intestine – digests most food •Large intestine – absorbs water; packages waste •Liver – makes bile to digest fat •Gall bladder – stores bile •Pancreas – makes enzymes to digest fats, proteins, and sugars •Path of food – mouth esophagus stomach small intestine large intestine • Response: • Brain – well-developed • Nerves – well-developed • Eyes – on top of head – can see and swim • Ears – located behind eyes • Nose – on top of head – can breathe and swim • Tongue – attaches at the front of the mouth •Excretion: •Kidneys – filter waste •Bladder – stores urine •Cloaca – removes waste •Respiration: •Gills when larva •Lungs as adults •Breathe through nares on top of head •Internal transport: •Cold-blooded – cannot control their internal body temperature •Heart – three-chambered (as adults) •Closed circulatory system – blood vessels •Spleen – makes red blood cells •Reproduction: •Separate males and females •Males attract female by making sounds with vocal sacs under the chin •Only sexually – no asexual reproduction •Male mounts female, she releases eggs, which he covers with a sperm solution – fertilization is external •Eggs swell and develop a protective coating – looks like a mass of jelly in the water Frogs vs. toads: •Frogs: •two bulging eyes •strong, long, webbed hind feet that are adapted for leaping and swimming •smooth or slimy skin (generally, frogs tend to like moister environments) •Frogs tend to lay eggs in clusters. •Toads: •stubby bodies with short hind legs (for walking instead of hopping) •warty and dry skin (usually preferring dryer climates) •paratoid (or poison) glands behind the eyes •The chest cartilage of toads is different also. •Toads tend to lay eggs in long chains. (There are some toads (genera Nectophrynoides), however, that are the only types of anurans to bear live young!)