Life is always changing, but it follows patterns
too. Living things—including ourselves—grow,
produce young, and die. There are repeating processes for
nonliving things too, from mountains, rocks, and rivers to
planets, comets, and stars. We call all these
patterns life cycles.
Life cycles are interlinked. Plants take nutrients and water from the soil
and energy from sunlight. Animals eat plants or other animals in order to
grow. Many plants rely on animals such as insects to spread their pollen so
they can make seeds and reproduce. When plants and animals die, their
remains rot and become part of the soil that will nourish new plants.