BIOL 102 Lecture 12: Chapter 30 Part 1

• School: USC, SC, Carolina, South Carolina
• Department: Biological Sciences
• Course: BIOL 102
• Professor: czako

Document Summary

Seeds changed the course of plant evolution, enabling their bearers to become the dominant producers in most terrestrial ecosystems. Seed=consists of an embryo and nutrients surrounded by a protective coat. Seeds can disperse over long distances by wind or other means. Seeds and pollen grains are key adaptations for life on land. In addition to seeds, the following are common to all seed plants: reduced gametophytes, heterospory, ovules, pollen. Gametophytes of seed plants develop within walls of spores that are retained within tissues of parent sporophyte (dependent gametophyte) Dominant in mosses and other nonvascular plants. Reduced, independent (photosynthetic and free-living) in ferns and other seedless vascular plants. Reduced (usually miscroscopic), dependent on surrounding sporophyte tissue for nutrition in seed plants. Reduced, dependent on gametophyte for nutrition in mosses and other nonvascular plants. Dominant in ferns and other seedless vascular plants. Megasporangia produce megaspores that give rise to female gametophytes. Microsporangia produce microspores that give rise to male gametophytes.