Chapter 1
Earth Science
Course: Elementary Education Multiple Subjects 5001
Subject: Elementary Education Science Subtest 5005
Chapter: Life Science
1. Life Cycles
A life cycle is the sequence of changes an organism experiences from the beginning of its life until it produces offspring and eventually dies. All living things—plants and animals—have life cycles, although they vary between species.
Basic stages common to most life cycles:
- Birth (or beginning stage such as egg or seed)
- Growth and development
- Maturity and reproduction
- Aging and death
Animal life cycles
Frog:
- Starts as an egg laid in water
- Hatches into a tadpole with gills and a tail
- Gradually grows legs and loses the tail
- Becomes an adult frog that can live on land and reproduce
Butterfly:
- Egg is laid on a plant
- Egg hatches into a caterpillar (larva)
- Caterpillar forms a pupa (chrysalis)
- Adult butterfly emerges and lays eggs