Lesson 2.4

Honey Bees and Pollinatiom

Grades: 4-6

Essential Skills: Science, Math

Duration: 1-2 class periods

OVERVIEW

Students learn about the importance of honey bees to Arizona agriculture and are introduced to the fascinating, colorful and complex world of flowering plants.

Preparation

Teacher Preparation:

Other Materials:

  1. Scissors or a single-edge razor blade for dissecting flowers
  2. Pins or pointers for arranging flower parts
  3. A hand lens or microscope (optional)

Information Sheets:

Activity Sheets:

Lesson Plan

Introduction activity (15 minutes)

Write the following quote from Dowden's The Clover and the Bee on the board: "For the million years man has lived on earth, flowers have been the glory of the green world around him. Their blossoming delights us all, from the youngest child to the oldest philosopher. But they do not exist for our delight, and their great beauty, in spite of what poets say, is not 'its own excuse for being.' All flowers, large or small, dull or spectacular, exist for one purpose onlyto make new plants."

Discuss the meaning of this quote. Reiterate the importance of honey bees and other insects in pollination of Arizona agriculture. Have students discuss what they have learned in previous lessons.

Activity 1 Foraging honey bees (30 minutes)

Have the students form into groups of three to four. Have the students in each group examine flowers around their homes or school grounds for foraging honey bees. Emphasize that foraging honey bees will not sting unless trapped or threatened, but it is still best to leave them alone.

When they find flowers with honey bees, the students should record aspects of the flower such as its color, size and shape, and what time of day they see the bees. Have one student count the number of bees seen visiting during a standardized amount of time (three minutes is good), while another keeps track of the time. Encourage students to count the number of visiting bees at several times of the day, and to record the temperature each time, if possible.

Have students compile their data, summarizing the number of bees seen on each type of flower. They should graph the results, using the data sheet provided Activity Sheet 28. Look for patterns in activity, such as what time of day the most bees were seen and what kinds of flowers they preferred. Did big flowers or small flowers have more bees? Did all the bees have full pollen baskets? Have students explain the results. Tell students to record other observations, such as the presence of other insects or spiders that might feed on bees.

Activity 2 Kaleidoscope of flower forms (60 minutes)

Give each student a copy of Activity Sheet 29 (parts of a generalized flower) to review. Discuss the parts and their function, making sure students can identify the basic flower parts.

If possible, bring in books with detailed drawings of a number of different kinds of flowers (such as The Clover & the Bee by Anne Ophelia Dowden) or a botany text.

Spread your floral bouquet out on a table, or better yet, in a circle of plastic cups. Number each type of flower with a 3X5" card at the base. Following the format of the table have the students work in small teams and decide upon the most important feature of all the flowers. Their responses should be recorded on the data form. Have them work as quickly as possible. The teacher should summarize the most important floral attributes on a summary sheet or the chalkboard for each of the numbered flowers.

Check Information Sheet 23 (Pollination Syndromes and Floral Characteristics) to help you decide what array of features unite to produce a flower that is attractive to bees, to hummingbirds, or a moth.

Discuss these features of floral color, form, reward, scent, etc., with the class. Have them guess what type of pollinator could be expected to pollinate each of the flower types. Try to get the students to think about the size of each flower and the size of the potential pollinator. Ask questions such as "Do their sizes match?" "Would the pollinator's tongue be long enough to reach the nectar?"

By coloring or constructing (with construction paper) a fanciful flower, the class will learn first hand more about the relationships between flower form and attracting or excluding certain pollinators. One team designs a flower and then writes down its characteristics and likely pollinator on a secret piece of paper. Another team tries to guess who pollinates this flower. Points could be awarded for the most original flower or most correct guesses for pollinator, etc.

Activity 3 Discussion questions (20 minutes)

Why are flowers so colorful?

To attract pollinators, those plants that don't have colorful flowers are likely to be wind pollinated.

Do some of the lines and spots on the petals lead to hidden nectar?

Spots or stripes on the petals serve as nectar guides to direct the bee to the nectar.

Do all flowers have strong scents? Which ones do and which ones don't?

No. Citrus blossoms smell more strongly than marigolds.

Do all flowers produce nectar?

No,for example grasses and many orchids do not.

Give an example of a flower that is really lots of tiny flowers grouped into a large attractive unit.

All flowers known as composites are actually groups of many tiny flowers, each with its own male and female parts. These clusters of flowers produce many seeds, one from each flower. Examples are daisies, sunflowers, mums and desert marigolds.

Is force required to open some flowers and extract the nectar?

Yes, for example snapdragons, alfalfa, and lupine.

How do flowers try to exclude illegitimate visitors (nectar robbers?)

Some orchids go to the extreme of false advertising. They have nectar guides but no nectar!

Do you think the amount of nectar produced by wind pollinated plants would be more or less than the amount produced by hummingbird pollinated plants?

The amount of nectar a flower produces depends on its pollinator and also factors such as time of day.

Additions

Extensions:

Words with special meanings:

(for understanding only, not to be tested)

  1. Anther
  2. Stigma
  3. Filament
  4. Style
  5. Ovary
  6. Petal
  7. Sepal

Bibliography:

Insects and Flowers: The Biology of a Partnership, by F.G. Barth. Published by Princeton University Press, Princeton, NJ, 1985.

The Clover & The Bee, A Book of Pollination, by A.O.T. Dowden, published by Harper Collins, 1990.

Roses Red, Violets Blue: Why Flowers Have Colors, by S. A. Johnson and Y. Sato. Published by Lerner, Minneapolis, M.N., 1991.

The Story of Pollination, by B.J.D. Meeuse. Published by the Ronald Press Company, N.Y., 1961.

The Sex Life of Flowers, by B. Meeuse and S. Morris. Facts on File, N.Y., 1984.

The Pollination of Flowers, by Michael Proctor and Peter Yeo. Published by Collins, London, 1973.

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