Life Cycle of Frogs

Life Cycle of FrogsDana Eisenbeil & Bomi SonSecond Grade Science

What is a frog? Frogs are amphibiansCold blooded animalsGills to lungsMetamorphism Life Cycle of FrogsEggTadpoleTadpole with legsFrogletFrog

Ask students this questionIntroduce topic of metamorphism

Photo: clip art2First Stage: EggA frog lays her eggs in the water or a wet environmentEggs attach to leaf or stemEggs split to form more eggsEggs collect to form frog spawn

Photo Source: http://www.packerlighting.com/CR_WEB/

Math exercise on cell division

During the egg stage is where organs of the frog begin to develop.What are similarities between frog organs and human organs? What are differences?

Many eggs do not survive.

Picture credit http://www.packerlighting.com/CR_WEB/

3Second Stage: TadpoleTadpoles come from hatched eggsTadpoles have gillsTadpoles have NO legsTadpoles use their tails to swim about their environment

Photo Source: http://bookbuilder.cast.org/view_print.php?book=35218

Ask students what gills are for.What other animals have gills?Connection of fish and tadpole

Photo credit: http://bookbuilder.cast.org/view_print.php?book=352184Third Stage: Tadpole with LegsDuring this stage, tadpole matures and developsForms front and back legsTail is still intact to assist in swimmingLUNGS begin to develop

Photo Source:http://exoticpets.about.com/od/frogsandtoads/ig/Tadpole-Development-photos/Tadpole-to-Frog-Metamorphosis-.--9l.htm

Ask students to predict what next stage is like

Explain how metamorphism influenced growth and developmentSkin, lips, mouth (jaw), tail (grows smaller) and legs mature What is the function of lungs?Breathe oxygenWhat are some animals that also breathe oxygen? (Mammals)

Photo Source: http://exoticpets.about.com/od/frogsandtoads/ig/Tadpole-Development-photos/Tadpole-to-Frog-Metamorphosis-.--9l.htm5Fourth Stage: FrogletFroglets legs and arms are more definedTail is smallerTransition from water to landFroglet explores dry landFroglet is dependent on oxygen to live and breatheLungs are fully developed

Photo Source:http://www.flickr.com/photos/vanja-gavric/2892988684/

Photo source: http://www.flickr.com/photos/vanja-gavric/2892988684/6Fifth Stage: FrogWebbed fingers and toesMakes moving on land and in water easySticky tongue for catching foodFull grown adult frog

Photo Source: http://yoga108.org/blog/posts/414-rainforest-frog

Explain length of time in which these changes occurExplain how the cycle continues again since female adult frog can lay eggs to restart cycle.

Photo source: http://yoga108.org/blog/posts/414-rainforest-frog7

The CyclePicture Source: www.frog-life-cycle.com

Photo Source: http://www.frog-life-cycle.com/

Hyperlink: Click picture to go to site

8