Plant Diversity and Life Cycles Biology 2 Chapter 29

Lycophyta- Nonvascular Plants Plants which lack xylem and phloem, the vascular tissues which carry water and sugars to all parts of the plant. Lack true leaves, roots and stems Hornworts, liverworts and mosses

Hornworts

Liverworts

Mosses

Life Cycle of Mosses The dominant form of a moss is a clump of leafy green gametophytes which produces the sperm and the egg Have alternation of generations The alternate form is called the sporophyte and produces the spores

Antheridium The male reproductive structures that produce hundreds of flagellated sperm by mitosis

Archegonium The female reproductive structure that produces a single egg by mitosis

Fertilization When sperm unites with the egg and begins dividing to form the zygote haploid haploid diploid

Sporophyte Grows from the tip of a gametophyte and remains attached to it Forms the spores by meiosis which are released and grow to produce the gametophyte

Seedless Vascular Plants Plants which reproduce by spores and lack vascular tissue Ferns, horsetails and whisk ferns

Pterophyta Ferns

Life Cycle of a Fern Has alternation of generations The sporophyte is the dominant form The gametophyte is tiny and forms the antheridia and archegonia

Sori Located on the underside of a fern frond and contain the sporangia where the spores are formed

Sphenophyta Horsetails, Equisetum Equisetum

Psilophyta Whisk ferns