1. To look at cellular specialization in plants, with emphasis on lignified cells that function in water transport and/or support.
2. To study the evolution of these vegetative structures in representative plants: a moss, a fern, a gymnosperm, and both a woody and a nonwoody angiosperm.
3. To examine the evolution of sexual cycles in a moss, a typical fern, and a gymnosperm.
By the end of this exercise, you should be able to identify the various lignified cell types in cross sections of stem. You should know how to tell a moss from a fern; a gametophyte from a sporophyte. You should understand which cells are haploid and which diploid, and whether they are formed by mitosis, meiosis, or fertilization. You should be able to apply this information to the reproductive cycle in gymnosperms such as pine.