Observing Progression from Flowers to Seeds

By Laura Hospitál on May 07, 2015

I have been surprised by how many of my students don't know what the function of flowers is for angiosperms (flowering plants).  Students' responses to that question have included  "to smell good",  "to feed the insects",  or "to give your girlfriend". 
 
This simple activity will connect the dots for students by allowing them to observe the progression from flowers to seeds over the spring.  This may be more feasible in the south where flowers go to seed early enough to observe this process before the students go home for the summer. 
 
Related vocabulary:
  • angiosperm - flowering plant
  • pollination - the transfer of pollen from the male reproductive strutures to the female reproductive structures in plants
  • fertilization - in angiosperms, the joining of the sperm and egg
  • pollen tube - a tubular structure that grows from a pollen grain, enters the embryo sac, and allows the male reproductive cells to move to the ovule
  • pistil - the female reproductive part of a flower that products seeds and consists of an ovary, style and stigma
  • ovary- in plants, the lower part of the pistil that produces eggs in ovules
  • ovule - a structure in the ovary of seed plants that contains an embryo sac and that develops into a seed after fertilization
  • stamen - the male reproductve structure of a flower that produces pollen and consists of an anther at the tip of a filament
  • anther - in flowering plants, the tip of the stamen, which contains the pollen sacs where grains form
  • filament- the long slender structure in a flowering plant which supports the anther- part of the stamen
  • sepals - in  a flower, one of the outermost rings of modified leaves that protect the flower bud
  • petals - one of the ring or rings of the usually brightly colored, leaf-shaped parts of a flower utilized by the flower to attract pollinators
  • seed - the part of a flowering plant (angiosperm) that will develop into a new plant given the right conditions
 

Preparation:

  • Find flowers near your student's school.  A nearby garden would likely allow you to visit if there is not a garden on campus.  Choose flowers to observe which will produce seeds that will be easily detected tactually.
  • I usually like to have student observe bluebonnets (the Texas state flower) because the seeds are contained in a pod.  Green beans are a common plant that would be a good plant to observe. 
 

Materials

  • None besides your walking shoes and flowers going to seed
 

Procedure

I like to have the students observe flowers as an introductory activity before we have studied plants but this activity would also be beneficial after initial instruction.  
  • When students arrive to class, take the class out for a walk (or, if necessary, a drive) to the gardens.
  • Have students observe various flowers.  
  • Discuss the flowers.  Is there one flower per stem or many.  Are flowers small or large?  Show the students some flowers that have only one per stem and others which display many flowers per stem.   Discuss the incredible variety among flowers. 
  • Ask - What is the purpose of flowers for a plant?  Discuss pollination and fertilization in angiosperms (See definitions). (If this is an introductory activity, do not explain the function of flowers to students yet.)
  • Pollination - the flowers attract insects which pollinate the plant
  • Fertilization -  in angiosperms, the joining of the sperm and egg
  • If this was used as an introduction to angiosperms, provide basic instruction on plant structure and angiosperm reproduction prior to the 2nd visit to the gardens.  The Dissection of a Flower activity would be an appropriate addition to instruction. http://www.perkinselearning.org/accessible-science/dissection-flower   A large  flower model will be helpful for instruction.  See the following reviews.                                                         

    http://www.perkinselearning.org/accessible-science/giant-dicot-flower-model

    http://www.perkinselearning.org/accessible-science/student-edition-giant-dicot-flower-model

  • Schedule a second trip to the same garden or area of campus.  The first trip should occur when the flowers you are observing have not gone to seed.  The second trip should occur as they are in the process of going to seed.
  • Have students observe the flowers.  They should notice that most of the petals are gone.  Ask - What has happened?  Have the students observe the seeds. Make notes of students observations or have a student do so.
  • Discuss pollination, fertilzation and the formation of seeds.     
  • When you return to class or for homework have students write a brief summary about the function of flowers as they understand it.
 

NGSS Standards:

2nd grade - Interdependent relationships in ecosystems
LS2.A: Interdependent Relationships in Ecosystems  - Plants depend on water and light to grow. (2-LS2-1) - Plants depend on animals for pollination or to move their seeds around. (2-LS2-2) LS4.D
 
3rd grade - Inheritance and Variation of traits: Life cycles and traits
LS1.B: Growth and Development of Organisms - Reproduction is essential to the continued existence of every kind of organism. Plants and animals have unique and diverse life cycles. (3-LS1-1)
 
4th grade - Structure, function, and information processing
LS1.A: Structure and Function - Plants and animals have both internal and external structures that serve various functions in growth, survival, behavior, and reproduction. (4-LS1-1)
 
Middle School: Matter and Energy in Organisms and Ecosystems:
LS2.A: Interdependent Relationships in Ecosystems - Organisms, and populations of organisms, are dependent on their environmental interactions both with other living things and with nonliving factors. (MS-LS2-1)
 
Middle School: Growth, Development, and Reproduction of Organisms:
LS1.B: Growth and Development of Organisms - Organisms reproduce, either sexually or asexually, and transfer their genetic information to their offspring. (secondary to MS-LS3-2) - Animals engage in characteristic behaviors that increase the odds of reproduction. (MS-LS1-4) - Plants reproduce in a variety of ways, sometimes depending on animal behavior and specialized features for reproduction. (MS-LS1-4)
 
 
 
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