BIOL 1202 Chapter : Chapter Learning Objectives Chp 30
Document Summary
Chapter 30: plant diversity ii: the evolution of seed plants. Spores were the main way that mosses, ferns, and other seedless plants spread over earth for the first 100 million years of plant life on land. Seeds represent a major evolutionary innovation that contributed to the opening of new ways of life for seed plants. Spores are usually single celled, whereas seeds are multicellular, consisting of an embryo protected by a layer of tissue, the seed coat. A seed can remain dormant for days, months, or even years after being released from the parent plant, whereas most spores have shorter lifetimes. Seeds also have a supply pf stored food. Under favorable conditions, the seed can emerge from dormancy and germinate, with its stored food providing critical support for growth as the sporophyte embryo emerges as a seeding. Concept 30. 2: gymnosperms bear naked seeds, typically on cones: gymnosperms have naked seeds that are not enclosed in ovaries.