Chapter 39 Lecture Enrichment Ideas
Provide specimens of flowers that have only "male parts" and others that have only "female parts." Describe how these may be found on the same plant or on completely different plants. Examine the corn flowers, for example, with the male tassel on top producing pollen and the female flowers with the long silks that lead to the ovaries; each corn kernel is a single fruit, and the cob is a stem on which the individual flowers and fruits develop.
Provide visuals showing how some plants have characteristics that attract animals as pollinators. For example, the shape of some orchid flowers resembles the reproductive organs of female insects, stimulating male insects to visit different flowers and attempt copulation, thus transferring pollen. The production of scent and nectar, and the bulls-eye markings visible to insects but not to humans, could also be discussed.
Describe the flowers of oak or other trees that do not have insect pollinators. Try to bring specimens or photographs, and compare how these flowers are different from what we normally think of as a flower.
Consider what happens when different kinds of pollen (from different species of plants) land on a flower's stigma. There must be antigenic (protein) recognition between the pollen grain and the tissue of the stigma for proper interaction to occur; and the genetic information for building a pollen tube of the proper length must be present if pollen germination does occur.
Current newspaper articles on newly engineered plants provide a relevant application of the techniques for genetic engineering explained in this chapter.
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