Students learn about the life cycles of different organisms, including a bird, a butterfly, a cockroach, and a frog.
After completing this tutorial, you will be able to complete the following:
All organisms have a life cycle. A life cycle includes all the stages in an animal's or an insect's life, including birth, development, reproduction, and death. Flowering plants have a life cycle that includes seed, seedling, growth, flower development, and pollination. The first stage of any animal's life cycle is the egg. A frog lays many spherical eggs at one time that stick to each other and float in the water. An egg develops into a young tadpole. Its body looks like a fish with a tail, and its legs are not yet fully grown. The young tadpole grows into an older tadpole that looks more like an adult frog. The older tadpole is distinguished from adults by its tail. Adult frogs have lost their tails and have large, fully grown legs. The life cycle of a butterfly also begins with a fertilized egg. The fertilized egg develops into a larva. The larva has a long body and many legs. The next stage is the pupa stage. The larva hangs on a tree branch, spins a silk thread, and wraps its body in this thread. This structure is called a cocoon, and it surrounds the pupa stage of the life cycle. When the silk-thread covering opens, an adult butterfly emerges. The life cycle of a cockroach also begins with a fertilized egg. Cockroach eggs are housed in a cylindrical case. The egg develops into a larva that is also known as a nymph, which looks much like an adult but has no wings. The nymph has a covering over its body that limits its growth. As the nymph grows, the covering breaks off or is shed. The adult cockroach is distinguished by its fully grown wings and large body. A bird's life cycle also begins with a fertilized egg. Bird eggs are spherical, with a hard, light-colored covering. A newly hatched chick looks much like an adult but its wings are not yet fully grown. The adult bird has fully grown wings, a beak, and a tail.
The metamorphosis of insects is observed in two different forms: complete metamorphosis and incomplete metamorphosis. Incomplete metamorphosis has three stages: egg, larva, and adult. The life cycle of a cockroach is a good example of incomplete metamorphosis. Complete metamorphosis includes the same stages as incomplete metamorphosis, with the addition of the pupa stage. The butterfly life cycle is a good example of complete metamorphosis.
|Approximate Time||2 Minutes|
|Pre-requisite Concepts||Students should be familiar with birds, frogs, insects, and mammals.|
|Type of Tutorial||Concept Development|
|Key Vocabulary||carbon cycle, consumer, decomposer|