BIO153H5 Study Guide - Midterm Guide: Cyanobacteria, Transpiration, Paraphyly
Document Summary
Microsporangia (male) produce microspores that develop into microgametophytes, the seed plants are a monophyletic group consisting of the gymnosperms (cycads, ginkgo, gnetophytes, and conifers) and the angiosperms (flowering plants). When pollen reaches the female reproductive structure of a seed plant, a non-motile sperm cell is transported to the female megagametophyte. The time required to complete seed development in gymnosperms is long it can take up to three years from pollination to completion of seed development. Gymnosperms are often very successful in extreme environments, particularly in subarctic climates. These palm-like plants are mostly found in tropical and subtropical regions today, and have remained relatively unchanged through their long evolutionary history. The central part of their trunk is a massive pith. Many are highly toxic, producing neurotoxins and carcinogens, but some have an edible pith called a sago. Most living gymnosperms are coniferophytes (pines, cedars, spruces, etc.
