The Kingdom Plantae Chapter 28

Characteristics of Plants Photosynthesis using chlorophylls a and b Storage of energy as starch. Cellulose cell walls. Zygote develops into an embryo while still attached to the parent plant. This separates the plants from the protists, specifically the green algae. (But may really be better to include the green algae in the Plantae.)

Embryos

Non-vascular plants (bryophytes) Mosses, liverworts, and hornworts No specialized water-conducting cells (xylem or phloem) Reproduction by spores Obvious, green parts of the plant are all haploid (gametophyte)

Vascular Plants (tracheophytes) Xylem – water-conducting tissues Tracheids: long, slender, hollow water-conducting cells Vessels: a more advanced form of water-conducting cell we’ll encounter later. Phloem – sugar-conducting tissues Diploid sporophyte becomes dominant generation

Non-seed tracheophytes Ferns – wide variety of growth forms Club-mosses (note: despite the name these are not mosses; they are vascular plants and are more closely related to ferns) Horsetails Whisk ferns Members of these groups were the dominant plants of the Paleozoic, and a major source of fossil fuels.

Figure 28.19 The Life Cycle of a Fern Egg Archegonium Rhizoids Germinating spore Mature gametophyte Antheridium Sperm Spore tetrad Fertilization HAPLOID (n) Gametophyte generation Meiosis DIPLOID (2n) Sporophyte generation Mature sporophyte Archegonial wall Sporangium Embryo Sporophyte Sori (clusters of sporangia) Root Horizontal stem Roots

Figure 28.19 The Life Cycle of a Fern Sori

Figure 28.13 Homospory and Heterospory Gametophyte (n) Archegonium () (n) Antheridium () (n) Spore (n) HAPLOID (n) Gametophyte generation Eggs (n) Sperm (n) Meiosis Fertilization DIPLOID (2n) Sporophyte generation Spore mother cell (2n) Zygote (2n) Sporangium (2n) Embryo (2n) Sporophyte (2n)

Figure 28.13 Homospory and Heterospory Megagametophyte () (n) Heterospory Megaspore (n) Microgametophyte () (n) Eggs (n) Microspore (n) HAPLOID (n) Gametophyte generation Sperm (n) Meiosis Fertilization DIPLOID (2n) Sporophyte generation Spore mother cell (2n) Spore mother Zygote (2n) Embryo (2n) Sporangium (2n) Sporophyte (2n)