Grade 3: Our Life Cycles

Lessons at a Glance


Lesson 1: Introduction to Life Cycles

Big Idea: All living organisms have life cycles that include being born, growing up, reproducing, and eventually, dying.

Children are introduced to the Life Cycles Unit. They brainstorm the concept of a cycle and discuss some of the cycles in their own lives. They also create a life-cycle diagram for a human.

 

Lesson 2: Exploring Life Cycles and Spans

Big Idea: All living organisms have life cycles that include being born, growing up, reproducing, and eventually, dying.

Children look at organisms pictured with their offspring. They notice that many offspring resemble their parents, while others do not. The children complete life cycle diagrams for a bean, a frog, and a sheep, and explore the concept that life spans of living things vary.

 

Lesson 3: Humans -- Life Cycles and Generations

Big Idea: All living organisms have life cycles that include being born, growing up, reproducing, and, eventually, dying. The stages of the human life cycle repeat from one generation to the next.

Children identify the human life stages portrayed in a family reunion photograph and recreate the life cycles of a grandmother, mother, and daughter.

 

Lesson 4: Humans -- Life Cycles and Generations (Interview)

Big Idea: All living organisms have life cycles that include being born, growing up, reproducing, and, eventually, dying. The stages of the human life cycle repeat from one generation to the next.

Children interview classroom guests from their parents' and grandparents' generations, using questions prepared in advance. During the interview process, the children develop a sense of the passage of time inherent to generations.

 

Lesson 5: Trees -- Fall Observations

Big Idea: All living organisms have life cycles that include being born, growing up, reproducing, and, eventually, dying. Physical growth and change are natural parts of the tree life cycle.

Children use their senses of sight, hearing, smell, and touch to observe a class tree. They predict how the tree and its surroundings might grow or change during their yearlong tree study.

 

Lesson 6: Trees -- Fall Measurements

Big Idea: All living organisms have life cycles that include being born, growing up, reproducing, and, eventually, dying. Physical growth and change are natural parts of the tree life cycle.

Children take baseline measurements of the class tree in order to track its physical growth from the fall to the spring.

 

Lesson 7: Humans -- Measuring My Physical Growth (Fall)

Big Idea: All living organisms have life cycles that include being born, growing up, reproducing, and, eventually, dying. Rapid physical growth is a natural part of the human life cycle until adulthood.

Children take baseline measurements of themselves in order to track their physical growth from the fall to the spring.

 

Lesson 8: Humans -- Measuring My Intellectual Growth (Fall)

Big Idea: All living organisms have life cycles that include being born, growing up, reproducing, and, eventually, dying. Intellectual growth is a natural part of the human life cycle.

Children learn that making new connections in the brain is the basis for intellectual growth. They explore a food sample and map out on a brain diagram the connections being made in their brains as they explore.

 

Lesson 9: Humans -- Survival Needs

Big Idea: Humans, like all animals, need food, water, air, shelter, security, and healthy sanitary conditions in order to survive. Humans also have emotional, social, and intellectual needs.

Children consider the basic survival needs of all animals as they design an adventure and explain how particular needs would be met. They recognize the basic needs of all animals as well as the needs humans have above and beyond these basic needs.

 

Lesson 10: Trees -- Growth Rings

Big Idea: All living organisms have life cycles that include being born, growing up, reproducing, and, eventually, dying. Trees are more likely to survive and thrive in each stage of their life cycle when their survival needs are met.

Children examine a cross section of a tree and learn how to determine its age. They observe that the distance between tree rings varies and speculate about the reasons why.

 

Lesson 11: Trees -- Winter Observations

Big Idea: All living organisms have life cycles that include being born, growing up, reproducing, and, eventually, dying. Physical growth and change are natural parts of the tree life cycle.

Children discuss how the weather during winter might affect the tree, and make observations of the tree and its surroundings. They also discuss the concept of dormancy.

 

Lesson 12: Seed to Seed -- Examining and Planting Seeds

Big Idea: All living organisms have life cycles that include being born, growing up, reproducing, and, eventually, dying. Seeds are an important stage in the life cycle of a plant.

Children begin a study of the life cycle of a pea plant. They examine seeds and learn about seed germination. They identify the parts of a seed that are instrumental to growth and plant seeds that they will observe over the next two months.

 

Lesson 13: Seed to Seed -- Transplanting and Stressing Sprouts

Big Idea: All living organisms have life cycles that include being born, growing up, reproducing, and, eventually, dying. Plants are more likely to survive and thrive in each stage of the life cycle when their survival needs are met.

Children transplant pea sprouts and begin tracking the plants' growth in both an optimal and a stressful environment.

 

Lesson 14: Butterflies -- Baby Caterpillars

Big Idea: All living organisms have life cycles that include being born, growing up, reproducing, and, eventually, dying. Caterpillars are an important stage in the butterfly life cycle.

Children begin studying the life cycle of butterflies. They observe, measure, and draw young caterpillars. They also start a life span calendar for the caterpillars that turn into butterflies.

 

Lesson 15: Butterflies -- Larger Caterpillars

Big Idea: All living organisms have life cycles that include being born, growing up, reproducing, and, eventually, dying. Physical growth and change are natural parts of the butterfly life cycle.

Children become more familiar with caterpillars: how they look, how they move, and how they behave. The children watch caterpillars eating and observe their limbs and locomotion. They also learn the caterpillar's basic body parts.

 

Lesson 16: Trees -- Spring Observations

Big Idea: All living organisms have life cycles that include being born, growing up, reproducing, and, eventually, dying. Physical growth and change are natural parts of the tree life cycle.

Children discuss how spring weather affects the tree, and make observations of the tree and its surrounding environment. They also discuss the stages of a tree's life cycle, and identify the likely stage of the class tree.

 

Lesson 17: Butterflies -- Chrysalises

Big Idea: All living organisms have life cycles that include being born, growing up, reproducing, and, eventually, dying. Chrysalises are an important stage in the butterfly life cycle.

Children observe the pupa stage of the life cycle of butterflies. They continue their observations and discussions of the butterfly life cycle, with an emphasis on the concept of metamorphosis.

 

Lesson 18: Seed to Seed -- Looking at Flowers

Big Idea: All living organisms have life cycles that include being born, growing up, reproducing, and, eventually, dying. Flowers are an important stage in the pea plant life cycle.

Children consider the part the flower plays in the life cycle of a plant. They review the parts of the flower to understand how it plays a critical role in seed formation.

 

Lesson 19: Trees -- Spring Measurements

Big Idea: All living organisms have life cycles that include being born, growing up, reproducing, and, eventually, dying. Physical growth and change are natural parts of the tree life cycle.

Children take final measurements of the class tree and calculate its physical growth since the beginning of the school year.

 

Lesson 20: Trees -- Study Results

Big Idea: All living organisms have life cycles that include being born, growing up, reproducing, and, eventually, dying. A tree has multiple annual cycles within its life cycle.

Children culminate their yearlong study of the class tree by illustrating the annual cycle of a deciduous tree and attaching it to a "Life Cycle of a Tree" poster. They discuss how the poster reveals the many annual cycles that occur within a single life cycle of a deciduous tree.

 

Lesson 21: Butterflies -- Adult Butterflies

Big Idea: All living organisms have life cycles that include being born, growing up, reproducing, and, eventually, dying. The adult is the final stage in the butterfly life cycle.

Children explore the final stage in the metamorphosis of the butterfly -- the adult. They examine the eating behavior and physical features of the adult butterfly, and then compare and contrast these characteristics with those of the caterpillar.

 

Lesson 22: Butterflies -- Generations

Big Idea: All living organisms have life cycles that include being born, growing up, reproducing, and, eventually, dying. The adult butterfly may reproduce and lay eggs that hatch to create the next generation.

Children continue to learn about adult butterflies. They observe butterfly eggs and discover the birth of a second generation as caterpillars hatch and the life cycle repeats.

 

Lesson 23: Seed to Seed -- Observing Fruits and Seeds

Big Idea: All living organisms have life cycles that include being born, growing up, reproducing, and, eventually, dying. Fruits are the final stage in the pea plant life cycle.

Children examine the fruits that developed on the class pea plants as well as a wide range of other fruits. They learn that the ovary is the part of the flower that develops into the fruit and reflect on the life cycle of the pea plant.

 

Lesson 24: Humans -- Measuring My Physical Growth (Spring)

Big Idea: All living organisms have life cycles that include being born, growing up, reproducing, and, eventually, dying. Rapid physical growth is a natural part of the human life cycle until adulthood.

Children take final measurements and calculate their physical growth since the beginning of the school year.

 

Lesson 25: Humans -- Measuring My Intellectual Growth (Spring)

Big Idea: All living organisms have life cycles that include being born, growing up, reproducing, and, eventually, dying. Intellectual growth is a natural part of the human life cycle.

The children review their new science understandings and skills they've learned over the school year. They demonstrate the skill they selected in the fall and practiced all year.

 

Lesson 26: Comparing Cycles

Big Idea: All living organisms have life cycles that include being born, growing up, reproducing, and eventually, dying.

Children create a "Who Am I?" guessing game using information that they recorded about the life spans, survival needs, and types of changes that humans, trees, pea plants, and butterflies undergo as they grow.

 

Skill Building Activity 1: Measuring Length and Circumference

Big Idea: You can measure the length of different sides of an object, or the distance around an object, or both, depending on its shape. Measurements are not exact; it's alright to round up or down to the nearest unit and say the object is "about . . . units long."

The children practice measuring the length and circumference of objects and rounding them to the nearest centimeter.

 

Skill Building Activity 2: Observing and Describing

Big Idea: Observation is a powerful tool for learning about something, and detailed and accurate descriptions help you communicate your observations.

Children practice making accurate and detailed descriptions before and after observing an object.

 

Skill Building Activity 3: Using Magnifiers

Big Idea: A magnifying lens makes things look larger than they really are. You can use a magnifying lens to examine objects closely and to see details that you might not see without it.

Children learn how to use a magnifying lens, like the ones supplied in the Science Companion kit. There is also an extension in which children learn how to use a jeweler's loupe.