Biology 213 Exam 1Practice Key - Instruction.greenriver.edu

23. (4) Explain how the seedless vascular plants suffered the loss of dominance during theCarboniferous period on earth?Plants called seedless vascular plants suffered because the plant was drying out due tothe cooling of the earth, the formation of glaciers, and drying out of the earth surfaces. Asthe marshes and swamps receded the available habitats that supported this lifestyle waseliminated.24. (6) Explain three characteristics exhibited by seed plants to give them the advantage onearth beginning in the Carboniferous period?Plants called vascular seed plants replaced spores with seeds because they were moreresistant to desiccation. The gametophytes became reduced and retained the embryonicsporophyte for protection. Reduced size of the male and female gametophytes and thezygote develops into an embryo packaged with a food supply. Finally pollen and pollinationpractices eliminated the need for water fertilization and favored wind and eventually insectassistance.25. (3) Describe how the ideas that attempt to explain the development of a microphyllic toeventually a megaphyllic leaf?Microphyllic leaves are thought to have evolved by the branching of the vascular channelsalong a stem, whereas the megaphyllic leaf probably evolved from further branching alongthe microphyllic initial branch.26. (3) Discuss two uses of the plants called gymnosperms by man?Gymnosperms are the large woody naked seed trees that populate our evergreen forests.We use their woody trunks for lumber to build things, we burn the bodies for heat, and someprovide medicines for our ailments (any other uses?).Biology &213 5Exam 1Mr. BrumbaughPage Score .