188.8.131.52 Life Cycles
Demonstrate an understanding that animals pass through life cycles that include a beginning, development into adults, reproduction and eventually death.
For example: Use live organisms or pictures to observe the changes that occur during the life cycle of butterflies, meal worms or frogs.
Recognize that animals pass through the same life cycle stages as their parents.
MN Standard in Lay Terms
All plant and animal organisms have life cycles which involve a sequence of changes.
All organisms living on Earth grow and change from birth until they are adults and are ready to reproduce. Children/offspring have the same life cycle as their parents. All living organisms have life cycles, but details differ for different organisms.
MN Standard Benchmarks
184.108.40.206.1 Demonstrate an understanding that animals pass through life cycles that include a beginning, development into adults, reproduction and eventually death. For example: Use live organisms or pictures to observe the changes that occur during the life cycle of butterflies, meal worms or frogs.
220.127.116.11.2 Recognize that animals pass through the same life cycle stages as their parents.
Educational video using time lapse to show the life cycle of the monarch butterfly to be used as a review at the end of a unit on insect life cycles.
"Plants and animals have life cycles that include being born, developing into adults, reproducing, and eventually dying. The details of this life cycle are different for different organisms." NSES Standards
Benchmarks of Science Literacy:
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
Common Core Standards
Language Arts: Writing: Presentation of Knowledge and Ideas:
Describe people, places, things, and events with relevant details, expressing ideas and feelings clearly.
Add drawings or other visual displays to descriptions when appropriate to clarify ideas, thoughts, and feelings.
Produce complete sentences when appropriate to task and situation, and respond to stories, poems, rhymes and songs with expression. (See grade 1 Language standards 1 and 3 on page 38 for specific expectations.)
Use basic concepts of measurement in real-world and mathematical situations involving length, time and money.
18.104.22.168 Measure the length of an object in terms of multiple copies of another object.
- There is a no continuity of life from seed to seedling or larvae to pupae.
- Death is not a part of a life cycle.
- Fail to recognize that all organisms have a life cycle.
- Hold some naïve thoughts about inheritance, including the belief that traits are inherited from only one parent.
From: Driver, R. (2002). Making sense of seondary science (pp. 49-50). London, England: Routledge:
Tamir et al. investigated the notion of continuity of life in children aged 10 - 14. Although most could put pictures of seed germination or chick embryology into the correct sequence and 85 percent said that the seedling was alive, only 66 percent said the seed was alive. It appears that 19 percent did not understand the continuity of life from seed to seedling: they believed in the possibility of living organisms developing from the nonliving, stating "seeds are dead, when we put them in the soil they get food and begin to live" or "larvae change into pupae which are dead and then we get butterflies." However, most of the children did have a notion of the continuity of life, explicitly stating, "If the seed were not alive it would not be able to grow" or expressing the idea that living organisms originate from other living organisms. In some cases the latter idea did not prevent the children from believing that eggs and seeds are not alive. However, of a class of agricultural school students in the sample, only one classified eggs and seeds as non-living, indicating that agricultural experience had an impact on understanding of the "life" concept.
In Ms. Flores' class students are quietly reading around the room. Some sit on pillows or in the comfortable chair, others are nested in corners. Ms. Flores is working with a small group of students practicing their sight words.
Suddenly Amari, who is sitting near the science table, calls out, "Look at the monarch cage - the butterfly is coming out!"
Students from all corners of the room gather around the monarch cage as the monarch emerges from its chrysalis.
"Eeuw, it's dripping blood."
"I hope it doesn't fall."
"Oh, look, its wings are getting bigger."
Ms. Flores tells students to bring their science journals to record their observations and to draw pictures. "What other details can we record?"
"Let's write down how long it takes until the wings spread out," Mai suggests.
Suggested Labs and Activities
In teaching this standard, a variety of organisms can be used. Insects are commonly used in the classroom as they have a short life cycle and students can observe all stages within the course of the unit. However if you have classroom pets, a bird sanctuary or opportunities to study other organisms in your location, these would be appropriate also. The fifth choice below, is a bird life cycle unit which uses video clips from Nature to show the various life cycle stages. This would make a great comparison study after students have studied live organisms OR the lesson might be used if live organisms are not allowed in the classroom.
2. Lessons 1 - 7: These lessons guide students and teacher through the rearing of monarchs along with journaling to document their life cycle. Students also conduct an investigation to determine how much monarch caterpillars eat. Lesson 7 provides black-line masters to make a monarch life cycle book. Oberhauser, K. (1999). Monarchs in the classroom. St. Paul, MN: University of Minnesota Department of Fisheries, Wildlife and Conservation Biology.
6. Lesson on the life cycle of a butterfly where students create a journal page with the life cycle of a butterfly, use butterfly cards to order the sequence of a butterfly life cycle, and write a song about the life cycle of the butterfly. Electronic sources are linked. Online science butterfly life cycle lesson
7. A lesson plan showing students how to make a diagram to show the life cycle of any animal. This lesson would be appropriate as a review for an organism that was reared and observed in the classroom. Diagram life cycles
The lessons are the same as for the above benchmark 22.214.171.124.1, being careful to emphasize the way the cycle continues as offspring go through the same cycle as their parents.
Having live animals in the classroom is a great way to teach life cycles. See the National Science Teacher Association position paper on teaching with live organisms. NSTA position paper on live animals in the classroom
Places to purchase live animals include:
Rearing suggestions by organism:
Monarch Butterfly University of Minnesota Monarch Lab Oberhauser, K. (1999). Monarchs in the classroom. St. Paul, MN: University of Minnesota Department of Fisheries, Wildlife and Conservation Biology.
- Life cycle: all the parts or stages of a living thing from birth to death. Examples: for insect: egg, larva, pupa, adult; for frogs: egg, tadpole, adult
- Offspring: children or descendant of a parent.
- Stage: time in development (growing up).
Language arts connection:
Read the nonfiction book, Animal Habitats by Michelle Kramer; the lesson includes ideas for units on frog life cycles, other animal life cycles, and the butterfly life cycle: ANIMAL HABITATS book unit
'97 Framework Life Science: Building understandings of biological concepts through direct experiences with living things, their life cycles, and their habitats.
Is Your Mama a Llama? by Steven Kellogg
Books from Lynne Bleeker's list of Life Cycle books linked below Bleeker, L. (2003, July). Lynne bleekers books list for science workshops. Retrieved from curriculum.risd41.org/committee/science/Book_List.doc
Assessment of Students
1. Draw and label the life cycle of one of the organisms studied. This is the main theme of the standard. It can be broken down in to smaller questions like: What is the first stage of the frog life cycle? What are the other stages?
2. What does our organism (frog) need to stay alive in the first stage? (As an egg.) Second stage? (As a tadpole.)
3. How is the life cycle of a frog like its parent's life cycle?
Assessment of Teachers
1. How do life cycles among various animals differ?
2. How do the needs of organisms change as they develop through their life cycle?
3. How does science account for similarities and differences among parents and their offspring? Which are genetic?
A. From: Corder, G. (2008) Supporting English Language Learners' Reading in the Science Classroom. In E. Brunsell (Ed), Readings in science methods, K-8: An NTSA press journals collection (pp. 223-227). Arlington, VA: NSTA Press.
Corder discusses three ideas to support English Language Learners in the Classroom:
1. Setting a Language Objective.
In general, stating an explicit objective for a lesson is considered a good teaching practice. An example of an objective in a science classroom might be "The student will determine the density of the sample." This example is a content objective and identifies "what a student should know and be able to do" (Echevarria et al. 2004, p. 21). English language learners' needs, however, extend beyond the science content alone. They need opportunities to listen, speak, write, and read English. Research suggests inclusion of language objectives along with content objectives. (Echevarria, Vogt, and Short 2004, p. 22). Language objectives range from lower order, such as, "The student will underline unfamiliar words in the passage," to higher order such as "The student will read the four authors' descriptions and synthesize a model." The language objective's level should vary based on the language proficiency of your students. All objectives must be comprehensible and explicitly communicated to students. The manner in which you direct students to an objective will determine its effectiveness: First, post the objective in a location that gives students access; second, orally state the objective; third, refer to the objective at the beginning and end of an exercise that demands reading.
2. Supplying Background Information.
Many English language learners enter our classrooms with a different set of experiences than their fluent English-speaking counterparts (Echevarria, et al. 2004). This means that many of them lack the background knowledge required for reading that many texts may take for granted. Therefore, teachers must supply that necessary background knowledge.
It may be necessary for you to "model how to follow steps of directions needed to complete a task" (Echevarria et al. 2004, p. 25) such as a lab or project. As you model, you can think aloud by orally stating the objects you are manipulating and your thought process as you proceed. Modeling supplies English language learners with a visual image and accompanying terminology from which they can draw when encountering those terms and concepts in a reading passage.
When students encounter unfamiliar words, a reading passage becomes more difficult for them (Dale and Chall 1948; Klare 1974). To counter this, you can pre-teach key vocabulary. All difficult terms should be considered, even those that are not considered science vocabulary. For example, you can create and maintain a word wall by defining, discussing, and posting words that students identify as unfamiliar. This technique provides valuable pre-reading instruction, while creating a resource to which students can quickly refer and reinforce English language gains.
3. Linguistic Modification of Text
Researchers have identified several specific characteristics that affect a text's level of difficulty, and you can draw on their findings when simplifying your own texts:
First, passages with longer words and longer sentences are more difficult to read (Bormuth 1966; Flesch 1948; Klare 1974).
Second, passive voice is not always as clear as active voice ( Forster and Olbrei 1973; Savin and Perchonock 1965; Slobin 1968). An example of passive voice is "The cause had been identified by scientists." An example of active voice is "Scientists identified the cause."
Third, a long string of consecutive nouns elevates reading difficulty (King and Just 1991; MacDonald 1993).
Fourth, a coordinate, or independent, clause is more difficult to read than a subordinate, or dependent, clause (Botel and Granowsky 1974; Wang 1970). A coordinate clause can stand by itself as a sentence, while a subordinate clause cannot.
Fifth, an abstract statement is more challenging to comprehend than a concrete statement (Cummins et al. 1998). An example of an abstract statement is "Record your data." An example of a concrete statement is "Record the volume of the cylinders in Table 1."
B. "Kit Inventory" Activity
Michael Klentschy, superintendent of El Centro Public Schools, El Centro, California, taught this activity at the NSTA Science and ESL conference in St. Louis, MO, April 2007.
Before teaching, collect the materials that will be used in a unit or lesson. Have cards ready to write the name of the materials for a word wall and designate a portion of the room for the word wall. You could also display the word wall on a display board for future use.
Divide the class into teams of three or four students. Have one student volunteer to introduce the first item. Show this one student the item and have them answer the following questions: What color is it? Where have you seen it before? What is it used for? Put the object in an opaque bag and the student then shares with the class the answers to the above questions. The student groups have 1 - 2 minutes to predict what they think the object is. Student groups share their ideas. Then the object is revealed and posted along with its word card on the word wall. Keeping the object or a picture of it next to the word card provides a resource for students as they proceed through the unit of study and need to find words for objects in the lesson.
Student can read about the life cycles of other organisms and present them to the class through posters, PowerPoint presentations or lecture.
A. From: Brown, P. L., & Abel, S. K. (2008) Science for All. In E. Brunsell (Ed), Readings in science methods, K-8: An NTSA press journals collection (pp. 215-217). Arlington, VA: NSTA Press.
Gay (2000) describes culturally responsive teaching as having these characteristics:
It acknowledges the legitimacy of cultural heritages of different ethnic groups.
It builds bridges of meaningfulness between home and school experiences as well as between academic abstractions and lived sociocultural realities.
It uses a wide variety of instructional strategies that are connected to different learning styles.
It teaches students to know and praise their own and each others' cultural heritages.
It incorporates multicultural information, resources and materials in all the subjects and skills routinely taught in schools.
Culturally responsive instruction should include authentic activities. Authentic activities provide students with the opportunity to explore how the subject under study is socially relevant and connected to their everyday lives. Instruction should move away from using a collection of disconnected hands-on activities and toward interaction and manipulation of ideas that are valuable beyond the school walls.
B. From: Allen-Sommerville, L. (2008). Capitalizing on Diversity. In E. Brunsell (Ed), Readings in science methods, K-8: An NTSA press journals collection (pp. 221-222). Arlington, VA: NSTA Press.
Eight Successful Field Tested Strategies:
- Assume that students can learn.
- Use exciting and challenging hands-on activities.
- Talk to students about their learning styles.
- Develop a repertoire of content strategies and activities.
- Learn about the history and culture of the various groups.
- Help students see themselves as future scientists and appreciate the multicultural history of science.
- Build opportunities for success into the curriculum and create climates conducive to learning.
- Provide diverse learning experiences.
C. Display posters depicting scientists from the students' cultural background doing science in the classroom. An easy way to do this is to take photos of your students doing science.
From Brunsell, E. (Ed.). (2008). Readings in science methods, K-8. Arlington, VA: NSTA Press.
Steele lists a number of ideas for teaching strategies to be used with special education students:
1. Collaborate with special education and general education teachers.
2. Create lessons based on themes or big ideas.
3. Incorporate explicit instruction on the lesson topics.
4. Use graphic organizers and visual representations.
5. Model behaviors and strategies you want students to follow.
Study strategies include:
1. Study guide use.
2. Material review tips.
3. Note-taking practices.
There is no replacement for observing the life cycle of an organism for understanding this concept. Allowing live organisms into the classroom generates excitement, engagement, and a sense of ownership for students. Funding and accommodating live organisms is a worthwhile endeavor.
Administrators observing a class will see students observing, feeding, handling, and asking questions about the organism in their classroom.
1. Parents can discuss physical family traits like hair and eye color, attached vs. detached earlobes, height, and more that are passed on through the family.
2. Discuss the life cycle of family pets.
3. This resource introducing a summer library program provides an in-depth tutorial for parents on how to teach and incorporate math and science to children. Ideas for parents to teach science from a Summer Library program brochure