ncert surendranaduthila

4. Characteristics of Frog

6. They use gills, lungs, skin, and mouth cavity in respiration.

7. They have moist, smooth, thin skin with no scales.Feet are webbed and the toes lack claws .

8. Frogs have many prominent characteristics that are adaptations to a life spent both on land and in water: They change from an aquatic larval stage to a terrestrial adult form. This transformation is called metamorphosis

11. HIBERNATION/ ESTIVATION Images from: http://www.enc.org/Classroom_Calendar/CC_Units/Unit_Images/185.jpg http://www.reptilis.org/pyxi/image5.htm FAT stored in FAT BODIES provides energy

12. Thin, moist skin – no scales Mucous glands make it “slimy” Camouflage- for protection Some have poison glands http://www-binf.bio.uu.nl/dutilh/hall/kikkers.html

13. Larvae have two-chambered hearts; adults have three-chambered hearts and well-developed circulation.

14. Eggs lack multicellular membranes or shells. They are usually laid in water or in a moist environment and fertilized externally.

15. Classification of Amphibians

16. Frogs and toads comprise the order Anura There are about 3,500 known species of frogs and 300 kinds of toads They are found on every continent except Antarctica