Animal Growth & Reproduction

Science, Grade 4

adult tadpole tadpole with legs froglet eggs Incomplete Metamorphosis Complete Metamorphosis Like all amphibians, frogs spend their lives near water because they must return to the water to lay their eggs. Animals produce offspring in a variety of ways. For example, many animals have live births. The offspring develops inside the female parent which gives birth to the live young. Other organisms, like chickens and frogs, lay eggs instead of having live births. Animal life cycles vary in how long they take. Some animals have short life cycles while others have longer. A life cycle is the stages of development an organism goes through starting from an egg to growing into an adult. Living organisms each have their own unique way of reproducing, giving birth, growing and developing. Butterflies and moths go through complete metamorphosis and undergo four stages of development: egg, larva, pupa, and adult. Complete metamorphosis involves considerable changes with each stage of development. Metamorphosis is the process of a rather sudden change in the appearance and form of some animals while growing into an adult. While most insects go through complete metamorphosis, some such as dragonflies go through incomplete metamorphosis. This life cycle includes three stages of development: egg, nymph, and adult. Frog Life Cycle 1 Frog eggs are laid in water. 2 Frogs hatch from eggs as tadpoles. They breathe with gills and swim using a tail. 3 The froglet still has part of its tail and starts to breathe using its lungs. 4 By the time a froglet becomes an adult, its tail is reabsorbed. Butterfly Life Cycle adult eggs larva (caterpillar) pupa (chrysalis) eggs nymph adult Dragonfly Life Cycle Animal Growth & Reproduction © Copyright NewPath Learning. All Rights Reserved. 94-4404 Mammals, like tigers, have live births. The offspring look like their parents from birth. 1 2 3 4
Incomplete Metamorphosis Complete Metamorphosis How do animals reproduce? _______________________________________________ ________________________________________________________________________ ________________________________________________________________________ What is a life cycle? ______________________________________________________ ________________________________________________________________________ What is metamorphosis? __________________________________________________ _______________________________________________________________________ Describe the stages of incomplete metamorphosis. ___________________________________________ ___________________________________________ Describe the stages of complete metamorphosis. ________________________________ ________________________________ Describe the stages of a frog life cycle. Frog Life Cycle adult life cycle amphibian live birth caterpillar metamorphosis chrysalis nymph eggs offspring froglet pupa hatch tadpole larva Key Vocabulary Terms 1 _________________________________ _________________________________ 2 _________________________________ _________________________________ 3 _________________________________ _________________________________ 4 _________________________________ _________________________________ Butterfly Life Cycle Dragonfly Life Cycle Animal Growth & Reproduction © Copyright NewPath Learning. All Rights Reserved. 94-4404 1 2 3 4 \|xiBAHBDy01711qzZ