4.1a Plants and animals have life cycles. These may include beginning of a life, devel-
opment into an adult, reproduction as an adult, and eventually death.
4.1b Each kind of plant goes through its own stages of growth and development that
may include seed, young plant, and mature plant.
4.1c The length of time from beginning of development to death of the plant is called
its life span.
4.1d Life cycles of some plants include changes from seed to mature plant.
4.1e Each generation of animals goes through changes in form from young to adult.
This completed sequence of changes in form is called a life cycle. Some insects change
from egg to larva to pupa to adult.
4.1f Each kind of animal goes through its own stages of growth and development
during its life span.
4.1g The length of time from an animal s birth to its death is called its life span. Life
spans of different animals vary.