Mader/Inquiry into Life, 9/e

Lecture Enrichment Ideas - Chapter 29

29.1. Characteristics of Plants

Discuss the major differences between plants and animals, focusing on plant's lack of nerves and muscles. Recent books on plants responding to singing, etc., provide new misconceptions that many students bring to this topic.

29.2. Nonvascular Plants

Transitioning from dominant gametophyte to dominate sporophyte requires good visuals to show the shift in life histories.

Discuss with students the need to use terms clearly and accurately in science; we do not designate "true roots" simply as science jargon, but because the apparent rootlike structures lack important features of genuine roots.

29.3. Vascular Plants without Seeds

The gametophyte stage of ferns is rather obscure and unnoticed; the small green heart-shaped structures can be grown from fern spores, on a wet peat plug in a covered clear plastic cup, and passed around as a demonstration in class.

29.4. Seed Plants

Many students have seen pine cones but not inspected the small seeds interleaved inside the scales; usually such specimens are easy to pass around in class.

There is a general misconception that flowering plants, derived later, are therefore superior. Point out to students the extensive coniferous forests circling the northern hemisphere, and the fact that pines are often the best plants for reclaiming some disturbed lands. The characteristic of being evergreen, having needles and pungent resins, etc., all have important implications for protection from snow loads, insects, etc.

One major concept of flowers is that they did not evolve for our appreciation but for the "selfish" value of cross-pollination. Visuals can show the close interdependence of many flowers with dedicated insects and birds; often involving the work of several great biologists. The "battle" among similar flowers to compete for generalist pollinators contrasts with another battle between plant's defense mechanisms and herbivorous insects.

One pervasive misconception is that evolution builds to more-and-more complex structures. The more primitive flowers have many replicated parts and derived flowers are often reduced; this concept holds for many animals as well.

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