The Beauty of A Flower - Structure and Function

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Objective

SWBAT to explain how flower structure increases probability of successful reproduction of plants.

Big Idea

Structure of flower increases probability of successful reproduction in plants.

Engage

5 minutes

To engage students in lesson I show students the following visually stunning video.  This time-lapse video shows a variety of flowers blooming.  Before starting the video make sure students know what time lapse photography is. The students are accountable to look for similarities across all flowers.  

After the video I lead a whole group discussion around the following questions:

  1. What is the purpose (i.e. function) of flowers?
  2. What were some of the similarities that you observed between flowers? (example:  similar structures)
  3. How is the structure of the flower well suited for its function?

The purpose of these questions is to guide students toward the lesson objective, which is for students to be able to explain how the structure of the flower increases the probability of its function, which is to increase the probability of successful plant reproduction. (CCC Cause and Effect  - Phenomena may have more than one cause, and some cause and effect relationships in systems can only be described using probability.)  

Explore

20 minutes

In this section of the lesson, students explore the structure of a flower by completing a Flower Dissection Lab.  

Lab Objectives

In this lab students are expected to:

  1. Dissect a flower and sketch it, labeling all the parts.
  2. Observe pollen grains and make a labeled drawing.
  3. Observe a pistil, which has been dissected, and make a labeled drawing of the ovary.

Materials

  1. Hand lenses
  2. Clear Tape
  3. Scalpel
  4. Color Pencils
  5. Lilies 
  6. Microscope
  7. Slides

Teacher Note:  The reason I choose Lilies as my flower of choice for the this lab is due to its large visible structures.  Fortunately for me I work close to our city's flower district and they are always willing to donate some flowers for this lab.

Explain

10 minutes

In this section of lesson I conduct a virtual flower dissection from BBC Science Clips. This virtual dissection works great if you have a SmartBoard, which allows you to demonstrate the dissection of each structure. If you have time you may have some students come up to the board and help you with the dissection. Take your time with the dissection, reading and using the "magnifying glass".

After completing the dissection we take, as a class, the provided quiz. There are a few ways you can do this. A quick way is to have students raise their hands when you say A, B, or C or hold up fingers (1 for A, 2 for B, etc.). Or, they can jot down their responses and do a turn-and-talk with a shoulder partner and then report out if they had a disagreement, or one changed their choice as a result of the discussion.

The objective of this activity is to reinforce what they have learned in class specifically the function of individual flower parts.

Elaborate

10 minutes

In this section of lesson students visit cK-12 to complete a reading on flowering plants.

Students read about the following topics:

  1. Flower Structure
  2. Flowers and Pollinators
  3. Flower Classification

To build and enhance understanding of new vocabulary I have students complete a Reading Activity.

Flowering Plants PrePostRead

Objective

To build and enhance understanding of the relationships between key words and to practice useful skills for designing information architecture using the Card Sort strategy.

Instruction

Pre-Read:  Before having students read the text, provide a list of words to individuals or groups of students on separate cards.  Students will sort and then categorize the words.  In class a student from each group can present and explain their categorization to the class.  Online students can chat with their peers using a chosen chat room. 

Post-Read:  Have students repeat this activity after reading the text.

Activity

Pre-Read:  Sort the following words into categories of your choice.  Give each category a title. 

Post-Read:  Repeat this activity after reading the text.

angiosperm

eudicots

ovary

pollen

stigma

anther

magnolids

petal

sepal

style

cotyledon

monocots

pistil

stamen

 

Evaluate

15 minutes

In this section of the lesson I have students design a flower whose structure will allow it to have optimal probability of having reproductive success.

Design a Flower

Have students work in groups to design models of flowers that are pollinated various ways.

  • One flower could mimic an insect to attract other insects for pollination. 

  • Another flower could rely on humans for pollination. 

  • Still another flower could be pollinated by the wind. 

Once students have designed their flowers students are required to make a claim that states why their flowers design is well suited for pollination (SP7 Engaging in Argument from Evidence/W.7.1 Write arguments focused on discipline content).

Students are required to make up empirical data that can be used as evidence to support their claim(i.e. % success rate, time needed for pollination, germination time).  To complete their claim students use scientific reasoning to support their explanation. (MS-LS1-4 - Use argument based on empirical evidence and scientific reasoning to support an explanation for how characteristic animal behaviors and specialized plant structures affect the probability of successful reproduction of animals and plants respectively.) 

Students use a Claims-Evidence-Reasoning (CER) format for their argument. I introduced and practiced CER with students in my Photosynthesis - Claim and Evidence lesson.

Once all groups have finished I display the designs in the classroom with small captions describing the flower's unique characteristics.

Teacher Note:  The three examples above are only suggestions, students can be creative and think of their own design.  The objective is for students to explain how their design increases plant reproduction.