Science
Strand III
Use Scientific Knowledge from the Life Sciences in Real-World Contexts

 

Science/Strand III
Content Standard 2
All students will use classification systems to describe groups of living things; compare and contrast differences in the life cycles of living things; investigate and explain how living things obtain and use energy; and analyze how parts of living things are adapted to carry out specific functions. (Organization of Living Things)

 

Science/Strand III/Content Standard 2
Middle School

 

Science/Strand III/Content Standard 2/Middle School
Benchmark 2
Describe the life cycle of a flowering plant.

Benchmark Clarification

Flowering plants, just like animals, have distinct stages in their life cycles. Fertilization, the first stage of a flowering plant, involves the union of egg and sperm. Seeds, which contain the embryos and their food, form in the ovary as a result of the egg/sperm union. As the seeds mature and the fruit ripens, the seeds may be dispersed. If conditions are favorable, the seed coat cracks open and the embryonic plant emerges (the seed germinates) and a mature plant develops with roots, stems, leaves, and flowers. The cycle of the flowering plant is ready to begin again.

Students will:

  • Locate the structure where sex cells form in a variety of flowers
  • Identify the stages of growth from seed to mature plant

Key Concept / Real World Context / Instructional Example / Assessment Example / Resources

 

Science/Strand III/Content Standard 2/Middle School/Benchmark 2
Key Concept
Flowering plant parts and processes:

  • roots
  • stems
  • leaves
  • flowers
  • fruits
  • seeds
  • embryo
  • pollen
  • ovary
  • egg cell
  • germination
  • fertilization

Tools:

  • microscope
  • hand lens

 

Science/Strand III/Content Standard 2/Middle School/Benchmark 2
Real World Context
Common flowering plants:

  • bean
  • tulip

 

Science/Strand III/Content Standard 2/Middle School/Benchmark 2
Instructional Example

Benchmark Question: What are the life cycles of living things?

Focus Question: What are the predictable stages of the life cycle of a flowering plant?

Students will dissect a variety of flowers to observe their structures. Dissection should be done carefully and sequentially, so structural parts are kept together. Students should then place a sheet of black construction paper on a table and gently tap the flower to collect pollen on the paper. They should examine the pollen under the microscope.

Specifically, they should:

1. Remove the petals and sepals to allow for closer observation

2. Examine the pollen-producing structures (stamens) and remove them carefully

3. Observe the remaining ovary structure by carefully slicing the ovary vertically in half. (Because this is a mature flower, fertilization has already taken place, meaning that the egg and sperm have already united and formed the tiny seeds they may see.)

Students should then discuss the role the flower plays in the life cycle of a plant. They should examine a variety of seeds, such as a lima bean, to observe the embryonic plants inside. They should hypothesize which areas will develop into the roots, stem(s), and leaves.

Then the students should design an investigation to determine what effect one variable might have on the life cycle of a flowering plant (e.g., photo-period [amount of sunlight], temperature, soil composition, water, fertilizer, competition [number of plants], acid rain).

Self-Evaluation Checklist for the Investigation

1. Problem

Š       Have you clearly stated the problem you investigated?

Š       What variables did you investigate?

2. Experiment

Š       Are your instructions for each step written clearly and completely enough so that someone else could easily replicate your investigation?

3. Results

Š       Are your data organized in a table, chart, or graph?

Š       Are your tables, charts, or graphs properly labeled?

4. Conclusions

Š       Are your conclusions fully supported by your data?

Š       How valid are your conclusions or results?

Š       In what specific ways could your experiment be improved?

Constructing: (SCI.I.1.MS.1), (SCI.I.1.MS.2), (SCI.I.1.MS.3), (SCI.I.1.MS.5).

Reflecting: (SCI.II.1.MS.5).

 

Science/Strand III/Content Standard 2/Middle School/Benchmark 2
Assessment Example

Students will create a model (PowerPoint presentation, flip-book, flowchart, picture book, song, poem) illustrating the development of a flowering plant .

( seed —> plant —> flower [ fertilization / fruit development ] —> cycling back to seed ).

(Give students rubric before activity.)

Scoring Rubric

Criteria

Apprentice

Basic

Meets

Exceeds

Correctness of plant development sequence

Shows inaccurate sequence of developmental stages of a flowering plant.

Illustrates partial sequence of developmental stages of a flowering plant.

Illustrates proper sequence of developmental stages of a flowering plant.

Illustrates detailed examples of numerous flowering plants moving through their developmental stages.

 

Science/Strand III/Content Standard 2/Middle School/Benchmark 2
Resources

Webliography.
http://mtn.merit.edu/mcf/SCI.III.2.MS.2.html

“Flower Study,” Budding Botanist. AIMS.
http://wwws.aimsedu.org/aimscatalog/default.tpl

The Lives of Plants. NEW DIRECTIONS UNIT.
http://www.BCMSC.k12.mi.us/

“Plants from Seeds.” GrowLab: Activities for Growing Minds.
http://www.kidsgardening.com/

Plants/Forests. Bill Nye Video. Disney Educational (800/295-5010).

http://www.fi.edu/tfi/units/life/living/living.html

Michigan Soybean Promotion Committee (free classroom kit)

P.O. Box 287
Frankenmuth, MI 48734

Wisconsin Fast Plants.
http://www.fastplants.org/