Biology 2241Z Lecture 6: 2217_lec11.pdf
Document Summary
The most important group of plants to humankind. Ceres, the goddess of grain, atop the chicago. Sheath encloses the stem: flowers: spikelets contain one or more florets; usually subtended by glumes. Grasses (cont. : evolved in cretaceous period (~65 mya, forests to deserts, most widespread plant, important for humans. 10,000 years fertile crescent: majority of food crops, paper making, animal feed, lawns. Organisms with rigid cellulose cell walls, chlorophyll a & b, . The grass family (poaceae: genera : 600 650, species: 9000 - 10,000. Alternate arrangement: both annual and perennial. Magnoliophyta: sporophyte and gametophyte are two stages in plant life cycle, sporophyte. Diploid plant that produces spores by meiosis: gametophyte. Haploid plant that produces sperm and eggs: wind pollination of haploid gamete spores. The flower: spiked flowers in inflorescences, small and incomplete. Lodicules take place of sepals and petals. Three stamens: single ovule in ovary.
