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Chapter 24
The Plant Kingdom: Gymnosperms
CHAPTER OUTLINE
Seed plants
Gymnosperms and flowering plants bear seeds
Gymnosperms
Conifers
CHAPTER OBJECTIVES
1. Compare the features of seeds with those of spores and discuss the adaptive advantages
of plants that reproduce by seeds.
2. Distinguish between a seed and an ovule, and define integuments.
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LECTURE OUTLINE
I. What are the characteristics of seeds?
A. How are seeds superior to spores as a means of reproduction?
B. What groups of plants bear seeds?
II. What are characteristics shared by all seed plants?
E. They are heterosporous.
III. What are the four phyla of gymnosperms?
A. What are their evolutionary relationships?
B. What does the word “gymnosperm” mean?
C. Gymnosperms do not need water for transport of sperm cells.
IV. What are some examples of conifers?
A. What are the characteristics of conifers?
1. What conducting cells form the wood of conifers?
2. What is resin?
winter?
B. What are the characteristics of the reproductive structures of conifers?
1. What does monoecious mean?
2. What are the reproductive strobili called?
3. What does the word “conifer” mean?
C. Describe the life cycle of pines.
D. The sporophyte is the dominant stage.
E. Some conifers, such a yew and juniper, do not have woody cones.
V. What are characteristics of cycads?
A. How is reproduction in cycads different from that in pines?
B. What primitive features are retained by modern cycads?
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VIII. What is the fossil evidence for the evolution of seed plants?
A. What are progymnosperms?
KEY TERMS
cone, p. 471
conifer, p. 471
gnetophyte, p. 477
gymnosperm, p. 469
pollination, p. 472
progymnosperm, p. 478
TEACHING TIPS
1. Take a short tour of the campus near your classroom. Point out features of the conifers
you see. If your college or university has a teaching greenhouse with a good
2. Female cones store well in classroom cabinets. Collect them whenever you travel. Male
3. Use visual aids such as overheads to discuss the life cycle of pines. Compare it to the
life cycle of ferns.
5. Discuss the similarities and differences between a pinecone and an angiosperm fruit.
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7. Display vegetation maps showing the distribution of vegetation associations and point
8. Bring in several conifers to key as a lab exercise. If no relatively simple key for conifers
is available, have students construct a simple key for four or five specimens.