Amphibians and Reptiles .
šø Amphibians
Amphibians are animals that live two kinds of livesĀ ā one in waterĀ and one on land.The word āamphibianā means ādouble life.ā
𧬠how they grow
When they are born, they start life in waterĀ as larvaeĀ (like tadpoles).They breathe with gillsĀ like fish and swim using a tail.Then, as they grow up, they go through a change called metamorphosisĀ ātheir gills turn into lungs, their tails shrink, and they grow legsĀ for land.
š§ why they need water
Even when they live on land, their skin must stay wet.Their skin helps them breathe oxygen directlyĀ from air or water.If their skin dries, they can suffocate.Thatās why youāll see frogs, salamanders, and newts in damp places.
𩸠body and life
They are cold-blooded, meaning their body temperature changes with the environment.They canāt make their own heat, so they use sunlight or shadeĀ to warm or cool themselves.They lay eggs in water, without shells ā just soft, jelly-like eggs.
š role in nature
They eat insects and worms, keeping pest numbers low.They are also food for birds, snakes, and fish ā a bridge in the food chain.They are very sensitive to pollution, so scientists use them as health indicators of ecosystems.
š Reptiles
Reptiles came after amphibiansĀ in evolution.They were the first vertebrates to truly live on landĀ without needing water for eggs.
š¢ body power
Their skin is dry and scaly, like armor āthe scales are made of keratin, the same stuff as our nails.This prevents water loss, so they can live in deserts or dry land.
𩸠temperature
They are also cold-blooded, like amphibians.They sunbathe to warm up and hide to cool down.
š„ eggs and life
They lay leathery eggs on land, not in water.Inside the egg is a protective shellĀ and an amniotic sac,which keeps the baby reptile safe and moist āthis was a huge step in evolution!
š¦ kinds
SnakesĀ ā no legs, flexible bodies, smell with their tongues.
LizardsĀ ā four legs, can regrow tails.
TurtlesĀ ā shells for armor.
Crocodiles and alligatorsĀ ā semi-aquatic hunters with strong jaws.
šæ why important
They control rodent and insect numbers.Ancient reptiles were the ancestors of dinosaursĀ and even birdsĀ today.
š§ quick deep thought:Amphibians are like the bridge between fish and reptilesĀ āthey taught evolution how to live on land.Reptiles took that idea and made it perfectĀ ādry skin, land eggs, and freedom from water.





