AP BIOLOGY

Detailed explanation-1: -Pollen and seed were innovative structures that allowed seed plants to break their dependence on water for reproduction and development of the embryo, and to conquer dry land.

Detailed explanation-2: -In early land plants, such as ferns, lycopods, horsetails and bryophytes (mosses, liverworts and hornworts), fertilization depends on a continuous layer of moisture, making these taxa poorly adapted to terrestrial conditions that experience extended dry periods (Longton & Schuster, 1983; Glime, 2013).

Detailed explanation-3: -Vascular plants include the clubmosses, horsetails, ferns, gymnosperms (including conifers), and angiosperms (flowering plants). Scientific names for the group include Tracheophyta, Tracheobionta and Equisetopsida sensu lato.

Detailed explanation-4: -Nonvascular seedless plants, also known as bryophytes, are classified into three phyla: mosses, hornworts, and the liverworts. Nonvascular plants lack seeds and vascular tissue. These plants are very short because they cannot move nutrients and water up a stem.