Pollination

Author(s): Anastasia Pickens and Arthur Millius

Lesson Overview

Grade level(s):

Grade 4

Subjects(s):

Biology/Life Science

Topic:

pollination

Big ideas(s):

Just as animals depend on plants (producers) for survival, flowering plants depend on animals (pollinators) for their survival.

Vocabulary words:

nectar, pollen, pollinator, pollination, interdependence

What you need:

two inflatible balls

4 colors of Post-its and 1 set of white Post-its

Flowers with obvious stamen and pistil (good flowers include lilies, alstroemeria)

TV/VCR

Grouping:

Part is whole class, part can be done individually or in pairs.

Setting:

For first activity with the balls either outside, in the gym or in the classroom.

Time needed:

2 sessions (45-50 minutes each)

Author Name(s): 
Anastasia Pickens and Arthur Millius
Summary: 

This activity approaches pollination through: 1) a game to understand the role of the pollinator, 2) a flower dissection to understand the structure and function of flower parts, and 3) a video to see seed dispersal in action. Allow 2 sessions to complete

Prerequisites for students: 
  • Students should have already learned about how animals depend on plants for survival (food: fruits, leaves, flowers, roots and shelter: build nests with plant material or often in a tree, sometimes insects lay eggs on/in a plant and their young develop there etc., oxygen: produced by plants via photosynthesis)
  • Students should have begun to learn about other ways that plants depend on animals for survival: (some plants like the venus fly trap get nutrients from animals they "eat", some animals sometimes feed on more dominant plant species, which can give other less dominant species a chance, seed disperal)
Learning goals/objectives for students: 

Explain how plants depend on animals for reproductive success (survival of the species).

Content background for instructor: 

In every ecosystem, organisms rely on each other in unique relationships that ensure each other's survival. Plants and animals are interdependent. All living things have basic needs and depend on other living things to meet those needs. Most flowering plants depend on animals for effective pollination and sexual reproduction. Animals are vital to the reproductive process of many plants and many animals rely on plants for food and shelter.

Lesson Implementation / Outline

Introduction: 

Pre-writing Prompt: All organisms depend on other organisms for survival. Do you agree or disagree with idea? Give examples to support your opinion.

Allow students 5 minutes to respond to prompt.

Call on volunteers to share responses with an aim of getting to the concept of different organisms have different functions: producers, consumers, decomposers, scavengers and that there are different processes going on between organisms: competition, predation, cooperation and symbiotic relationships.

Be sure to discuss what animals get from plants for their survival (food: fruits, leaves, flowers, roots and shelter: build nests with plant material or often in a tree, sometimes insects lay eggs on/in a plant and their young develop there etc., oxygen: produced by plants via photosynthesis).

Activity: 

 

ROLE OF POLLINATORS

Pollination is important because flowering plants can ONLY reproduce with a little help from their friends, the pollinators. When a honeybee flies to a flower looking for nectar, pollen from the blossom sticks to the fuzzy hairs on their body. When it visits the next flower, the pollen rubs off, pollinating the flower. If it were not for honeybees performing pollination, many fruit trees would not produce fruit.

Ask students to name some pollinators. Write on the board different groups of pollintaors: moths, bats, butterflies, bees, beetles, flies hummingbirds. Discuss their flower preferences (see chart at bottom of page on http://www.kidsgardening.com/growingideas/projects/jan03/pg1.html).  Discuss how the animal is looking to get food, while the the flower's job is to attract the pollinator. Ask students if plants and animals want to help each other. NO, but it works out well that they do. Let's explore exactly what happens.

1) Arrange the students in a circle, and give each student the same colored mini-Post-it, with numbers that represent half the number of students in the class. For example, if you have 30 students, you will have two sets of Post-its numbered 1-15 (so you will have two students with #1, two students with #2 etc.).  You will also need a ball, which represents the pollinator.  In each scenario (round) the ball must always get a post-it (pollen) from each student, (flower).

2) Round One: Explain that the ball represents a pollinator, let's say a honey bee. Each student represents a flower (in this first scenario, all flowers are of the same species (or type)). The ball will start in the circle with no post-its, the first student who gets the ball will put his/her post-it on the ball and not get one (since the bee has just left the hive and gone to the first flower).  If he/she gets the ball again they can take a post-it, but the important part, at first, is to get your pollen out there. In order to get pollinated, you must catch the ball, take off a Post-It (with a different # from your own/different pollen), put your Post-It on the ball and pass the ball on. The goal is to be as fast and efficient as possible because the honeybee needs to get back to the hive and you want to ensure the survival of all the flowers in the field. Set a stopwatch for 30 seconds and begin passing the ball and exchanging numbers. The only number a student cannot take is the same number she/he already has. When the timer goes off, explain that students who did not get a differnent number were not fertilized, and therefore cannot reproduce (at least at this point)--plants that don't reproduce disappear. Discuss ease or difficulty of pollinating the flowers and the dependence on the pollinator.

3) Round Two: Nature is complicated. Not all flowers are the same (there are many different species or types in a habitat) and most flowers can't pollinate themselves; the pollen must come from another flower of the same species. Each student now gets one of three different colored Post-its to represent different types of flowers in a field (for example, if you have 30 students, 10 get pink, 10 get yellow, 10 get blue).  In order to pollinate, the flower must exchange a Post-it on the "honeybee" that is the same color (i.e. from the same type of flower).  If they catch the ball and it has the same color Post-it, they can exchange Post-its, then pass it on. If the color on the ball and the color the person has are different, the ball must be passed on (since the types of flower types don't match) with the hopes they will get it again with a matching color. (*The ball should start with no Post-its (no pollen) , students should put on a post-it even if they can't take one)

4) Round Three: Now use two balls (i.e. two pollinators) and pass out white post-its to replace some of to the colored post-its (for example in a class of 30 you could have 6 white post-its, 8 blue post-its, 8 yellow post-its and 8 blue post-its)--one ball represents a bat and the other a honey bee. The bat can only pollinate a night blooming white flower, such as from a Saguaro catcus, (so only the students with white post-its). The honey-bee ball can still pollinate the other day blooming flowers (so the students with the colored post-its).  This round is to show that not only does the right type of pollen have to be transferred by the pollinator to the flower, but that in addition, not all flowers can be pollinated by all pollinators (some pollinators pollinate during the day and some pollinate at night).

5) If time permits, hand out attached Pollinators sheet and bring in flowers. Ask students to match flowers to possible pollinators to review and assess understanding that different flowers require different pollinators, hence animals and plants have evolved differently.

 

STRUCTURE AND FUNCTION OF PLANT REPRODUCTIVE PARTS

1) Handout a drawing of a simple flower to glue into science notebooks (see attachment and web link below for flower diagrams).

2) Explain that we have just explored how pollination happens out in nature, now we will look at how pollination works within a plant.

3) Hand out one flower per student and walk them through the parts from the outside to the inside discussing the name of each structure, and its function. Students can make a structure/function chart in their notebooks or write the function under each structure name on their labeled flower.

Flower Structure (part) and Function (job)

stamen--male parts of the flower (these include the anther and filament)

filament (supports the anther)

anther--produces pollen, which contains male sex cells, the sperm

petals-(usually colorful) and attracts pollinators

sepals--protects developing flower bud

pistil--female parts of the plant (these include the stigma, style and ovary (ovules are contained within the ovary)

stigma-sticky top of pistil that receives the pollen grains

style (the passage way for the pollen to move from stigma to ovary)

ovary-deep in bottom base of pistil, this becomes the fruit.  The ovary contains the ovule, which hold the female sex cells, the eggs

ovule- where the seeds develop

4) Understanding the structure and function of a simple flower helps students appreciate the effort it takes for plant reproduction to happen. Explain that not ALL pollination relies on other organisms, some tiny, plain flowers rely on an abiotic factor: the wind.

5) Explain that seed dispersal is another way that plants survive since young plants have a better chance of survival with more space and light than would be provided by the parent plant.

6) Watch FOSS video, How Seeds Get Here...and There, a video on seed dispersal (**My 4/5 grade class laughed a lot at the level of production, but the message is very clear)

Checking for student understanding: 

1) Ask groups of 3, each with a different colored pencil or marker, to draw an answer to the following questions:

a) (Should have been learned in an earlier lesson) Show 3 examples of how animals depend on plants for survival (Possible answers: food: fruits, leaves, flowers, roots and shelter: build nests with plant material or often in a tree, sometimes insects lay eggs on/in a plant and their young develop there etc., oxygen: produced by plants via photosynthesis).

b) (Some of this will need to have been learned in an earlier lesson) Show three examples of how plants depend on animals for survival (Possible answers: pollination, seed dispersal (should have been talked about in a separate lesson), some plants like the venus fly trap get nutrients from animals they "eat", some animals sometimes feed on more dominant plant species, which can give other less dominant species a chance).

Tell students that you want to see equal amounts of all three colors.

2) Give Science Notebook No. 5 (Foss Binder pg. 233) as homework or independent follow-up

Wrap-up / Closure: 

Ask students to return to the original prompt to re-read and add any new information based on today's lesson. Individuals may volunteer to read their responses.

Extensions and Reflections

Extensions and connections: 

The Honey Bee Article is an excellent Language Arts extension describing the plight of bees in the U.S.

Too long? Cut out unnecessary words or sections.

Perfect for shared reading on an overhead or small groups to emphasize importance of bringing background information (text to world) to non-fiction reading.

Reflections: 

This lesson is an extension of the 4th grade Environments FOSS Kit. They dedicate two pages (81 & 82) to discussing the role of animals in plant survival. The student Science Resource book has readings on page 108 that could be a follow-up or assessment.

AttachmentSize
POLLINATORS.doc79 KB
Honey Bee Article Teacher Edition.doc40.5 KB
Honey Bee Article.doc39 KB
Flower_parts labeled with function.jpg168.45 KB