Transcript AMPHIBIANS & REPTILES ARE ADAPTED FOR LIFE ON LAND

AMPHIBIANS & REPTILES
ARE ADAPTED FOR LIFE ON
LAND
• VERTEBRATES ADAPTED TO LIVE ON
LAND.
• AMPHIBIANS HAVE MOIST SKIN & LAY
EGGS WITHOUT SHELLS.
• REPTILES HAVE DRY, SCALY SKIN & LAY
EGGS WITH SHELLS.
• BODY TEMPERATURES OF AMPHIBIANS &
REPTILES CHANGE WITH THE
ENVIRONMENT.
Vertebrates Adapted to Live on
Land
• Amphibians (frog/toad/salamanders) &
Reptiles (turtle/snake/lizards/crocodiles)
have adapted to live on land.
• Some fish can breathe air and walk short
distances on land.
• Some amphibians have adapted to life only
in water.
Amphibians: moist skin & eggs
without shells
• Most adult amphibians have: 2 pairs legs (4 limbs),
lay eggs in water, get oxygen thru smooth, moist
skin, have lungs, sense organs adapted for land.
• Most live in moist or damp environments
• Reproduce sexually (female lays eggs in water &
male fertilizes them in water with sperm); offspring
develop & hatch on own- yolk inside eggs gives
nutrients; soft shells so water (with dissolved
oxygen) can pass through.
Amphibian Life Cycle
• Young amphibian hatches as a larva (tadpoles for
frogs & toads; look & act like small fish- breathe
via gills, swim with tail)
• After few weeks, tadpole’s body changes (lungs
develop, tail shrinks, legs form)
• Young frog’s body changes: gills stop working so
breathes with lungs, uses tongue to capture & eat
small animals, uses legs to move around on land.
• Some amphibians stay near water (sirens,
bullfrogs), while some just go to moist areas
(wood frogs, toads, salamanders)
Reptiles have dry, scaly skin &
lay eggs with shells
• Most have 2 pairs legs (total 4 limbs); have
tough, dry skin covered by scales; get oxygen
from air with lungs; sensory organs adapted for
land; lay eggs (with shells) on land.
• Lungs: born with lungs, filled with tiny blood
vessels where oxygen is exchanged with carbon
dioxide waste.
• Dry, scaly, skin: covered with scales made of
keratin (like fingernails). Thick, waterproof skin
protects from environment & predators (but can’t
exchange oxygen through skin).
Reptile Eggs with Shells
• Reptile egg lets
vertebrate animals
survive in hot, dry
environment.
• Eggs have everything
embryo needs (water,
nutrients, gas exchange).
• Reptiles reproduce
sexually (sperm
fertilizes egg, then shell
forms around it-while
still within female).
• Female finds place to
lay eggs (usually nest or
buries them).
Amphibians & Reptiles are
Ectotherms
• Are Ectotherms: body temperature changes with
environmental conditions; can move more quickly
when warm. Usually warm themselves in sunlight.
• Most of food is changed right into energy. Some
(alligator & tortoise) may survive long time without
eating food.
• If too hot or too cold, body stops working well.
(usually live where temp. doesn’t change too muchor may hibernate & slow down body processes in
cold)
• Many live near water to cool off.