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?
  
  

Misconception: Living things can come from nonliving sources (i.e., seeds, eggs, and pupae are nonliving).

Fact: Living things come from living things. Seeds, eggs, and pupae are all living things, just different stages of life.

Misconception: All organisms have the same life cycle.

Fact: Organisms can have different life cycles, but they all go through birth, growth, reproduction, and death.

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

The Waggle Dance

Honeybees love to eat sweet nectar. Nectar is a sugary liquid that plants make. Honeybees also eat pollen. Pollen is a powder that plants make. Because they eat plants, honeybees are consumers in the food chain.

Sometimes a bee will find a new source of food. When this happens, the bee does a “waggle dance.” This dance lets all the other bees know about her discovery. This dance gives a lot of information. It describes how far away the food source is. It also tells how much food there is and its direction from the hive.

Working Together

Communication is important for honeybees. They are social animals. They live in large groups called colonies. Their nest is called a hive. Beehives can have anywhere from 20,000 to 80,000 bees depending on the time of year.

The colony is very organized. Each bee has a specific job to do. Some bees do hive chores. These chores include producing wax and building the hive. Some bees guard the hive. Other bees leave the hive to gather nectar and pollen. Some bees tend to the young. This social structure is important. A single bee cannot grow or survive alone.

The Honeybee’s Life Cycle

When a bee gets enough food and water, it will grow and develop. Its body will go through changes. To change means to make something different from what it is now.

The changes all living things go through as they grow and develop form a pattern. This pattern is called a life cycle. A life cycle includes the stages an organism goes through on its way from birth to death.

All life cycles include birth, growth, reproduction, and death. Reproduction is the ability of a mature organism to have offspring. Without reproduction, a group of organisms would die out.

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.