review questions
1. What are the two major groups of seed plants?
Answer: Gymnosperms and Angiosperms.
2. How did seed plants evolve from earlier seedless vascular plants?
Answer: Seed plants evolved from earlier seedless vascular plants by developing
seeds, which provided protection and nourishment for the embryo, enhancing
survival and dispersal.
3. What critical innovations distinguish seed plants from their ancestors?
Answer: The development of seeds, pollen, and wood.
4. Why are gymnosperms referred to as "naked seed" plants?
Answer: Because their seeds are not enclosed within fruits.
5. What adaptations allow gymnosperms to thrive in cold and dry habitats?
Answer: Thick cuticles, needle-like leaves, and the ability to produce antifreeze
compounds.
6. How does wood provide structural support and transport water in gymnosperms?
Answer: Wood contains lignin, which strengthens the plant, and tracheids that
conduct water efficiently.
7. What are the key characteristics of cycads, ginkgos, conifers, and the order
Gnetales?
Answer: Cycads have palm-like leaves and coralloid roots; ginkgos are long-lived
and resistant to pollution; conifers produce cones and are adapted to cold
climates; Gnetales include diverse species with unique reproductive structures.
8. Describe the unique reproductive structures and strategies of conifers.
Answer: Conifers have simple pollen cones and complex ovule-bearing cones;
pollen is wind-dispersed.
9. What are the defining features of angiosperms?
Answer: Flowers, fruits, and enclosed seeds.
10. How do flowers contribute to the reproductive success of angiosperms?
Answer: Flowers attract pollinators, ensuring efficient pollen transfer and
fertilization.
11. What are the four types of flower organs and their functions?
Answer: Sepals (protection), petals (attraction), stamens (pollen production),
and carpels (ovule production).
12. How do monocots and eudicots differ?
Answer: Monocots have one cotyledon, parallel veins, and flower parts in
multiples of three; eudicots have two cotyledons, net-veined leaves, and flower
parts in multiples of four or five.
13. How have whole-genome duplication events contributed to angiosperm
diversification?
Answer: They provide genetic material for evolutionary innovation and new
traits.
14. What adaptations help in fruit dispersal?
Answer: Fruits can be adapted for wind dispersal, animal ingestion, attachment
to fur, or water transport.
15. How does coevolution shape the relationship between plants and pollinators?
Answer: Plants and pollinators evolve traits that benefit each other, increasing
reproductive success.
16. What is "pollination syndrome," and how does it influence plant-pollinator
interactions?
Answer: Specific flower traits attract particular pollinators, ensuring effective
pollen transfer.
17. What are some examples of pollination by insects, birds, and bats?
Answer: Bees prefer blue/yellow flowers; birds prefer red, odorless flowers;
bats prefer pale, fragrant flowers.
18. How does seed-dispersal coevolution benefit both plants and animals?
Answer: Animals gain food from fruit, while plants benefit from seed dispersal
to new locations.
19. How has domestication influenced the traits of angiosperms?
Answer: Humans have selected for desirable traits like larger fruits and
reduced seed dispersal mechanisms.
20. What are some examples of artificially selected traits in crops?
Answer: Sweet corn, seedless watermelons, and high-yield wheat.
21. How did the domestication of bread wheat occur?
Answer: Through hybridization and whole-genome duplication of wild ancestors.
22. Why is the loss of "shattering" important in agricultural plants?
Answer: It prevents seed dispersal, making harvesting easier for humans.