Key Terms
Trend across plant evolution
Sporophyte becomes increasingly dominant.
Homosporous
Produces one type of spore; gametophyte bisexual Lignin: tough hydrophobic polymer; waterproofs xylem; provides structur
Heterosporous
Produces microspores (male) and megaspores (female)
Sporangium
Structure where spores are produced by meiosis Sporophyll: leaf modified to bear sporangia Sporophyte: diploid (2n) mult
Sporopollenin
Tough polymer surrounding spores and pollen; highly resistant to degradation; found in spore walls AND pollen grains; en
Apical meristem
Zone of undifferentiated dividing cells at root and shoot tips; responsible for length growth; separate lateral meristem
Alternation of generations
Haploid and diploid multicellular stages alternate in life cycle Archegonium: female gametangium; protects and nourishes
Embryophyte
Land plant; embryo protected and nourished by gametophyte
Fiddlehead (crozier)
Rolled tip of developing fern frond Frond: large leaf of a fern; photosynthetic and reproductive Gametophyte: haploid (1
Haplodiplontic
Having both haploid and diploid multicellular stages
Mycorrhizae
Mutualistic symbiosis between plant roots and fungi
Peristome
Moisture-controlled tissue around moss capsule opening; regulates spore release Phloem: vascular tissue; transports suga
Hornworts
Stomata on sporophyte. Mosses: stomata on sporophyte only (NOT on gametophyte).
Charophytes
Phragmoplasts, plasmodesmata, apical growth. Chlorophytes: phycoplasts, no plasmodesmata, no apical growth.