BSC 2011 Chapter Notes - Chapter 30: Dicotyledon, Herbaceous Plant, Xylem
2 Oct 2016
School
Department
Course
Professor
Document Summary
Chapter 30 plant diversity 2: the evolution of seed plants. Transforming the world: seed: consists of an embryo & its food supply, surrounded by a protective coat. When mature, seeds are dispersed from their parent by wind or other means. 30. 1 seeds & pollen grains are key adaptations for life on land. All seed plants have reduced gametophytes, heterospory, ovules, & pollen: freed seed plants from requiring water for fertilization enabling reproduction under a broader range of conditions than in seedless plants. Helped seed plants cope with conditions such as drought & exposure to ultraviolet (uv) radiation in sunlight. Advantages of reduced gametophytes: bryophytes have life cycles dominated by gametophytes, seedless vascular plants have sporophyte-dominated life cycles, gametophytes of seedless vascular plants are visible to the naked eye. Gametophytes of most seed plants are microscopic: miniaturization allowed for an important evolutionary innovation in seed plants: Tiny gametophytes can develop from spores retained within the sporangia of the parental sporophyte.
