AP BIOLOGY

Detailed explanation-1: -Nonvascular Plants. Nonvascular plants (often referred to collectively as the bryophytes) include three groups: the mosses (Bryophyta), approximately 15, 000 species; liverworts (Hepaticophyta), approximately 7500 species; and hornworts (Anthocerophyta), approximately 250 species (Table 1).

Detailed explanation-2: -Non-vascular plants are those without a vascular system (that is they lack xylem and phloem ) and grow from spores. They do not have roots, stems, or leaves (although the lobes of some liverworts can look like leaves). Some non-vascular plants however do possess specialized tissues for internal transport of water.

Detailed explanation-3: -The ferns, gymnosperms, and flowering plants are all vascular plants. Because they possess vascular tissues, these plants have true stems, leaves, and roots.

Detailed explanation-4: -: a simple, low-growing, nonflowering plant (such as a moss or liverwort) that lacks specialized conducting channels for transporting water and nutrients and in which the photosynthetic gametophyte is the dominant stage of the life cycle.