6
Amphibians and reptiles
Textbook: Part 1, pp. 26–29
GoalKnow the features of amphibians and reptiles, the development of a frog, and be able to tell the two groups apart.
New words
tadpole · itbaliqamphibian · amfibiyareptile · sudralib yuruvchi
Explanation
Amphibians (frogs, toads) spend part of their life in water and part on land. A frog lays eggs in water and a tadpole hatches. The tadpole breathes with gills and lives in water, while the adult breathes with lungs and through its moist skin. A frog catches insects with its long sticky tongue. Reptiles (lizard, snake, tortoise, crocodile) have dry skin with scales or a shell and lay eggs on land. Both groups are cold-blooded, so they like to warm up in the sun. A snake senses smells with its tongue.
Worked examples
A frog’s development: egg → tadpole → adult frog.
A tortoise and a crocodile are reptiles because their skin is dry, with shell or scales; a frog is an amphibian with moist skin.
Class activity
“Which group?”: the teacher names an animal (snake, frog, lizard, toad, tortoise). Children raise the right hand for amphibian and the left hand for reptile. Then draw the 3 stages of a frog’s development.
Practice
1
How does a tadpole breathe? And an adult frog?
tadpole with gills; adult frog with lungs and skin
2
Which are amphibians: toad, snake, frog, lizard?
toad and frog
3
Why do reptiles warm up in the sun?
They are cold-blooded; their body temperature depends on the surroundings.
4
What does a snake use to sense smells?
its tongue