2.4.3.1 Life Cycles

Grade: 
2
Subject:
Science
Strand:
Life Science
Substrand:
Evolution in Living Systems
Standard 2.4.3.1

Plants and animals undergo a series of orderly changes during their life cycles.

Benchmark: 2.4.3.1.1 Plant Life Cycles

Describe the characteristics of plants at different stages of their life cycles.

For example: Use live organisms or pictures to observe the changes that occur during the life cycles of bean plants or marigolds.

Overview

Standard in Lay Terms 

MN Standard in Lay Terms

Students will observe and sequence that plants have a life cycle that includes sprouting; developing roots, stems, leaves, and flowers; reproducing; and eventually dying.

Students will also understand that the life cycle of plants is different from the life cycle of animals.

Big Ideas and Essential Understandings 

Big Idea

All living things go through changes as they grow and develop.  Although individual organisms die, new ones replace them, ensuring the survival of the species.  During its life cycle, an organism goes through physical changes that allow it to reach adulthood and produce new organisms.  Since these changes are common within a species, they can be grouped into stages of development.

Benchmark Cluster 

MN Standard Benchmarks

2.4.3.1.1  Describe the characteristics of plants at different stages of their life cycles. For example: Use live organisms or pictures to observe the changes that occur during the life cycles of bean plants, Wisconsin FAST plant or marigolds.

Correlations 

NSES Standards

Life Science; Content Standard C:  As a result of activities in grades K-4, all students should develop understanding of:

  • The characteristics of organisms
  • Life cycles of organisms
  • Organisms and environments
  • Organisms have basic needs.  For example, animals need air, water, and food; plants require air, water, nutrients, and light.  Organisms can survive only in environments in which their needs can be met.  The world has many different environments, and distinct environments support the life of different types of organisms.

AAAS Atlas:  No correlation found.

Benchmarks of Science Literacy:  No correlation found.

Framework for K-12 Science Education

Plants and animals  have predictable characteristics at different stages of development. Plants and animals  grow and change. Adult plants and animals  can have young. In many kinds of animals,  parents  and the offspring themselves engage in behaviors  that  help the offspring  to survive. 2LS1.B

Misconceptions

Student Misconceptions 

See: Alerts to Student Difficulties and Misconceptions in Science

  • Fruits have the potential to develop into new plants, when in actual fact, fruits are either eaten or decompose.
  • In the life cycle of a flowering plant, the fruit develops before the seeds.
  • There is no continuity of life from seed to seedling or larvae to pupae.
  • Death is not a part of a life cycle.
  • Students fail to recognize that all organisms have a life cycle.
  • Students hold some naïve thoughts about inheritance, including the belief that traits are inherited from only one parent.

Vignette

From: Lowery, Lawrence F., (1997). NSTA Pathways to the Science Standards (Elementary). Arlington, VA: NSTA Press.

The life cycle is an important principle in biology.  It represents the stages an organism passes through from its own birth to the birth of the next generation.    

In Alice Borden's class, the children have been growing FAST plants for several days.  They have been measuring the height of the plants, writing descriptions of how the plants change each day, and drawing in their journals.  While the plants grow, the students have been reading relevant books from the library.

In several more days, the students will harvest the seeds from the adult plants.  They will observe and study them, then plant them to start another life cycle.

As the children carry out their study, Mrs. Borden moves from group to group, posing questions and assessing the children's understanding of what they see.  She adjusts the instruction as a result of her assessment of their responses.

Some of the questions Mrs. Borden asks on different days are:

  • What is the best way to keep a record of the changes we observe from day to day?
  • How can we take our records and organize the information to explain to someone else what we have learned?
  • Describe the cycle of a plant we studied.
  • Make a drawing of the plant.
  • How is our knowing about the life cycles of plants important to us?

Resources

Instructional Notes 

Suggested Labs and  Activities

In this lesson, students learn about the life cycle of plants by watching a time-lapse video.  This activity provides students with further evidence that all living things grow and change as they progress in their life cycle.  Two optional video segments show students how to set up a germination experiment and how to grow the seeds they find stuck on their socks.

While we tend to think of plants as stationary, they are in constant, very slow motion as they respond to environmental factors.  Watch plants move in time-lapse videos in this interactive activity adapted from Indiana University.

In this media-rich lesson, students observe plant growth by watching a time-lapse video and by growing their own seeds. They identify the conditions seeds need to germinate and consdier the role that fruits play in seed dispersal.

This site contains a wealth of information and activities on life cycles of plants and animals.  It can provide needed enrichment or review activities.

Lots of activities and worksheets to familiarize pupils with the life cycle of plants from seed to dispersal. Click on a button to enter an activity.

This lesson supports students interacting with nature and provides them with a        framework for their observations by offering them opportunities to explore, question, and document similarities and differences among plant parts.

In this movie, students learn about the life cycle of a plant. Students explore how a seed can germinate and sprout, grow into a seedling, and then turn into an adult plant.

Instructional Resources 

Teacher Background information

  • A life cycle shows how a living thing grows, changes, and reproduces. While plants' life cycles are continuous, the study of one plant's life begins with the seed.  It is important that children understand that plants can also grow from cuttings, bulbs, tuber pieces, or runners.  Some seeds have an outer layer called a seed coat or hull, which provides protection and nourishment for the embryo inside.
  • When a seed germinates, a small root begins to grow downward and a shoot grows upward.
  • When the shoot breaks the surface, the plant is called a sprout.  Sometimes the seed coat is still clinging to the sprout when it surfaces.  The sprout uses water and nutrients from the soil along with sunlight and air to grow and change into a seedling.
  • A seedling is a small plant with few leaves that is vulnerable to the elements.  Eventually the seedling changes into a young adult plant.  At this stage, the plant is bigger and may have more leaves.  Thin branches will develop on young adult trees.
  • Over time, the young adult plant will grow into an adult plant, which is sexually mature and has the ability to reproduce through spores or flowers.
  • After flowers are pollinated, they enlarge and turn into fruit with seeds inside.
  • The skin and flesh of the fruit protects the seeds and after the fruit ripens and decays, the seeds can start the life cycle all over again.  Because there are so many threats to both seeds and seedlings, a plant will often produce large amounts of seeds to insure some will survive.

The 5 E method (Engage, Explore, Explain, Expand, Evaluate)

This is always an excellent procedure for working with young students.  Following is an example of how this method could be used with a plant cycle.

Engage:

  • Concepts:
    • Plants have life cycles.
    • Plant goes through stages of growth and development that include seed, young plant, and adult plant.
  • Teacher brings in a live plant. Teacher asks:
    • What are the parts of a plant?
    • Which part is the beginning part of the plant?
    • What do students think are the stages of a plant cycle?

Explore:

  • In groups, students plant seeds.

Explain:

  • Concepts:
    • Seeds needs air, water, and warmth.
    • Plants need air, water, sunlight, and nutrients in order to live and thrive.
  • Students name the factors that seeds will need to grow into an adult plant.

Expand:

  • Teacher asks students:
    • What happens if there is no watering?
    • In places where farmers grow crops, what happens if there is a drought?
    • If I grow the seed in the cupboard, will it germinate?

Evaluate:

  • Over the weeks, students will:
    • Keep a journal to illustrate each stage of growth.

Plant Life Cycle Activities and Lesson Plans

A wide range of excellent plant activities to do with students.

New Vocabulary 

Vocabulary/Glossary

  • Life cycle: a series of stages all living things go through that includes being born, developing into adulthood and eventually reproducing.  (Context: The life cycle of a monarch last for  about three weeks.)
  • Organism: any living thing,plant or animal.  (Context: Insects, trees and flowers are all types of organisms.)
Technology Connections 

Gamequarium: Plant Games

An extensive list, including: The Life Cycle of Plants, The Life Cycle of Plants 2, Living Things: Plants, Life Cycle Plant Parts.

Plant-Parts

An interactive web site where students correctly identify the part of the plant illustrated and it is added to the salad they are making.

National Geographic

Background information, often including descriptions of life cycles, on many animal species. 

The Smithsonian Institution

A website geared toward educators, although it also has resources for students and for parents.  Once on the site, click on "Educators," and then search for lesson plans, field trip ideas, websites, and more by grade level and subject matter.

The United States Department of Agriculture (USDA)

Website includes a Kids' Science Page that offers science books, Internet links, and educator resources on several subjects, such as plants and animals associated with agriculture.

Monarch Butterfly USA

Excellent pictures and explanations of the monarch's life cycle.

The Great Plant Escape

From the University of Illinois Extension, guides students through mock mysteries to unlock the "secrets" of plant life. 

Promethean/Smart Board suggestions:

All About Plants

This flipchart was created for a first grade class and introduces students to the main parts of a plant as well as the plant life cycle.

Seed to Plant (flipchart)

An overview of how a seed grows into a plant.

Plant Life Cycle (SMART Notebook lesson)

Lesson on six stages of a flowering plant.  Includes three video links for students to take notes.

Plant Life Cycle (SMART Notebook lesson)

Introduces students to the life cycle and parts of a plant.

Plant and Animal Life Cycles (SMART Notebook lesson)

This is a SMART Board lesson for life cycles of a bean plant and a butterfly.  It has video, click and reveal, and click and clap.  Use the pull-tabs for directions.

Life Cycles of Plants and Animals (SMART Notebook lesson)

This SMART Board lesson shows how things change over time and how both plants and animals change in their life cycles.  Students demonstrate what they've learned on a Venn diagram and a t-chart.

All About Plants (SMART Notebook lesson)

An review of plant parts and their jobs, needs, life cycle, deciduous or evergreen, plant products, and plants and animals as partners.

Interactions of Living Things (SMART Notebook lesson)

Second Grade Science Discovery Works Curriculum on Interactions of living things.  Key vocabulary terms and definitions as well as links to brain pop.

SMART Board Goodies

This website contains lots of SMART Board goodies for teaching students about life cycles, classification of living things, and has some great games.

Cross Curricular Connections 

From NSTA Pathways to the Science Standards:

The K-2 student...learns best by building understanding from their own actions upon objects and by telling stories about what they did and what they found out.  As they impose their ideas on the world, trying things out to see what will happen (poking, pushing, feeling, etc...), children see the results of their actions and thus come to understand how part of their world works.  If these experiences are connected with language experiences (e.g. talking with students as they explore instead of having a summary discussion after an exploration), primary students will learn how to express what they have learned in clear and accurate terms.

ELA

Writing

2.6.7.7  Participate in shared research and writing projects (e.g., read a number of books on a single topic to produce a report; record science observations).

Social Studies

  • US/World History  2.1.1.1.1
    • Historical Thinking
    • Historians organize the past into chronological units of time.
    • Use and create calendars to identify days, weeks, months, years, decades, centuries, and seasons; use and create timelines to chronicle personal, school, community, and world events.

Assessment

Assessment of Students

  • Ask students to draw a sequence of stages that shows an example of a complete cycle. (They may start anywhere within the cycle.)
  • Use a growth chart to show plant growth.  Use pictures and words to journal the seed's growth.  Do the students see the growth, and can they put into words what is happening?
  • Ask students to sequence sets of cards that depict the stages in the life cycle of three different organisms and to talk about the similarities and differences in the sequences.
  • Life Cycles of Plants and Animals Question set (SMART Response question set): Use the Senteo interactive response system to test knowledge of how plants and animals change during their life cycles.

Assessment of Teachers

  • Are seeds living organisms?  What is their main purpose?

(Every seed is a living organism prepared to produce a plant similar in every way to the parent plant that gave rise to it.)

  • What are the four stages that both plants and animals have in their life cycle?

(The life of a plant can be seen as a cycle from seed to young plant to adult plant making seeds back to a seed.)

  • Do plants have the same needs throughout their life cycle?

(The things a plant needs to survive are not always the same throughout its life cycle; for example, seeds don't really need sunlight or nutrients.)

Differentiation

Struggling Learners 

Struggling and At-Risk

The most important modification for this concept is giving these students extra time to complete the activities.  They could also create less detailed drawings and could orally report their findings.  In addition, they could give simple oral responses to questions on topics presented in class.

English Language Learners 
  • Given illustrations, students recognize similarities between plants or between animals
  • Students label a picture of a plant's life cycle  
  • Students give simple oral responses to questions on topics presented in class.
Extending the Learning 
  • Students design and build a habitat for a living organism that can be modified to meet the changing needs of the organism during its life cycle.
  • Remind students of the stages of human development such as newborn, toddler, child, teenager, young adult, middle-aged adult, elderly adult.  Ask students if there are comparable stages in the life cycle of plants.
  • Give each student a piece of paper and have them draw and color pictures of plants that they think correspond to each of the stages of human development.  (For example, a seed with newly sprouted roots would represent a newborn plant.  A tall tree, with many branches, would illustrate a middle-aged tree.)
  • If possible, take students on a stages-in-the-life-of-a-tree hunt.  Can they find a seedling, sapling, young adult tree, and very mature tree?  How about a dead tree?  Have them carefully draw examples of the stages they are able to find.
  • Plan, design, build, and grow a school garden (organic, hydroponic, and regular gardening).
Multi-Cultural 
  • The St. Paul Public Schools' Multicultural Resource Center has a variety of resources available to support multicultural science instruction. From their website:
  • Educators have often overlooked cultural beliefs and perspectives in science education, however recent research emphasizes the importance of recognizing diversity in the science classroom.  Recognizing diversity facilitates a more active learning experience for the student because it emphasizes understanding in terms of different perspectives rather than just learning the facts.
  • Students will develop a multicultural perspective while discovering that certain plants grow naturally in different places.  Compare and contrast available plant life with that of other environments and people.  Utilize the opportunity to appreciate certain foods found here and abroad.
  • Students will be learning about the life cycles of a butterfly relating it to the diversity and uniqueness of people.
Special Education 
  • Allow students to work as partners to complete a booklet illustrating the life cycle of a plant.
  • Plant Life Cycle
  • Students study plant life and its life cycles.  In this plant life lesson, students complete a KWL chart about plant life knowledge.  Students then plant a seed, care for it, and observe the plant for a week.  Students draw pictures of the plant and their observations.  Students write the definitions of related terms and draw a diagram of the plant and its parts.  Students take an oral quiz about the lesson.

Parents/Admin

Classroom Observation 

Administrators

Administrators should see a variety of plants growing in different stages.  Students should be recording these stages in their science notebooks.  Photos of plants going through the life cycle changes should be easily seen with the parts labeled.

Parents 

Plant Misconceptions for Parents

Describes the misconceptions children have about life cycles.

How do plants grow?

Website from Craft Jr. provides 12 printables on plant life and how plants grow, including a sequencing activity or matching game, word search, vocabulary list, and two printable mini-books that children can color and easily assemble.

Plants for Kids!

Kids can learn about the fascinating world of plants using these fun experiments, free games, science fair projects, interesting quizzes, amazing facts, cool videos and other resources.

The Science of Spring

This is a great site where kids can learn about seeds and plants using a hands-on activity in which they observe seeds, plant them, and watch them grow.

Comments

Vocabulary

Would it be possible to list or link to any vocabulary in the earlier and next grade levels that connects to the topic or concept in the benchmark. It would help teachers to know what the students should know before they start the unit and where it will lead.

Second comment. Are the vocabulary from both the benchmarks and the test specs? They do use different words and in some cases use different words or add words in the specs. Also can the where the words come from be identified. I suggest benchmark words in one color, test spec words in another, in both a combo, and words not in either, but needed another. Ex. A word only in benchmarks in BLUE, word in only in test specs in RED, a word in both PURPLE (ie red and blue together makes purple) Yellow for a word that is needed, but not in any of the state documents.