Life Cycles

In this lesson, students observe the life cycles of two different insects: the milkweed bug and the darkling beetle. They compare the patterns of growth and development, and analyze how although different organisms have different life cycles, all life cycles have in common birth, growth, reproduction, and death.

• All living things share certain characteristics, including the need for energy, nutrients, and water.
• Honeybees cannot get what they need to survive on their own. Instead, they depend on their hive for survival.
• Beehives can be understood from a systems perspective, in the same way that ecosystems are systems because they are made up of different living things, as well as air, water, sunlight, and Earth materials (rocks, soils, etc.).
• All organisms have in common birth, growth, reproduction, and death, but there are various ways that organisms move through each of these stages.
• Bees and other insects have a life cycle that involves metamorphosis—a life cycle with a change from an immature form to an adult form.
• Some insects undergo incomplete metamorphosis—a life cycle with three stages: egg, nymph, and adult.

• Why do all organisms need food?
• Why are honeybees an important part of the ecosystem?
• Why is communication important among honeybees?
• How does living in a group help honeybees survive?
• How is a beehive an example of a system? What would happen to the beehive if one part became damaged, such as if the queen dies?
• Why is reproduction an important part of a life cycle?
• Why do the main stages of all life cycles always follow the same direction: birth, growth, and reproduction?
• How is a plant life cycle similar to a honeybee’s life cycle?
• What is the life cycle of the honeybee?
• How does an organism move through incomplete metamorphosis?

Adaptation : a trait that helps an organism survive in its environment

Change : to make something different from what it is now

Function : the normal action of something or how something works

Life Cycle : the series of developmental stages an organism passes through on its way from birth to death

Metamorphosis : a life cycle with a change from an immature form to an adult form

Reproduction : the ability of a mature organism to have offspring

Structure: the way in which parts are put together to form a whole

Heredity : the passing on of traits from parents to children

Inherit : to receive a trait from your parents or ancestors

Trait : a physical or behavioral characteristic of an organism

For the hands-on activity in this lesson, students develop a model of the life cycle for the milkweed bug and the darkling beetle to describe the stages that each insect goes through. Students create a habitat for the milkweed bug and the darkling beetle, and then observe each insect over the course of its lifespan. They use their life cycle models to explain the cause-and-effect relationship between each step in the life cycle and to draw the conclusion that although different organisms have different life cycles, all life cycles have in common birth, growth, reproduction, and death.