Chapter 22

6. modified leaf that bears a sporangium or sporangia
8. an appearance of a hybrid between a tree fern and a palm
11. tough outer protective layer, especially that of an animal or plant.
12. flowering plant's unit of reproduction, capable of developing into another such plant.

1. plant that has seeds unprotected by an ovary or fruit. Gymnosperms include the conifers, cycads, and ginkgo.
2. of the phylum gingophyta that has fan shaped leaves and fleshy seeds
3. central part of an ovule, containing the embryo sac.
4. a division of plants, grouped within the gymnosperms
5. a plant or invertebrate animal) having the male and female reproductive organs in separate individuals.
7. grain:each of the microscopic particles, typically single cells, of which pollen is composed. Pollen grains have a tough coat that has a form characteristic of the pollen-producing plant and which can still be recognized in some archaeological deposits.
9. primary subdivision of a fern frond the term is also applied to a leaflet of a compound leaf
10. sticky flammable organic substance, insoluble in water, exuded by some trees and other plants (notably fir and pine).
12. coat:the protective outer coat of a seed.