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Plant Kingdom Biology 112 Vascular Plants Moss-like plants evolved into more complex structures that contained vascular tissue Specialized cells to conduct water and nutrients throughout the plant Considered to be a transport system Transport Main component of xylem – the major subsystem of plants that transport water from its roots to all parts of the plant Hollow cells with thick cell walls that resist pressure Phloem transports nutrients to all parts of the plant Both can move fluids, even against the pressure of gravity Ferns and their relatives Have true roots, stems and leaves Roots absorb water and nutrients and water Stems support the plant and connect the roots to the leaves as well as carry water and nutrients Leaves are photosynthetic organs that contain one or more bundles of vascular tissue Ferns Contain vascular tissues, roots, creeping or underground stems called rhizomes and large leaves called fronds Club Mosses Responsible for the Earth’s first forests Today, small plants that live among larger trees Horsetails Rare Only existing genus contains nonphotosynthetic leaves arranged in whorls joined along the stem Seed Plants Two major classifications Gymnosperms Bear seeds directly on the surfaces of cones Ex. Conifers such as pines and spruces Angiosperms Also referred to as flowering plants Bear their seeds within a layer of tissue that protects the seed Ex. Grasses, flowering shrubs and trees, wildflowers Seed Plants - Reproduction They can live in both aquatic and land environments Such plants have either cones or flowers, the transfer of sperm through pollination, and the protection of embryos in seeds Exhibit both a sporophyte as well as gametophyte stage Seeds do not require water for fertilization Cones and Flowers Cones are sporophyte structures Flowers are angiosperm structures Allow seeds to develop Pollen Male gametophyte is contained in a pollen grain Carried by wind, water or insects to the female structure Seeds The embryo of a plant Represents the early stage of the sporophyte reproductive cycle Seed coat protects the embryo and prevents it from drying out Benefits of Being a Seed Plant The seed can survive environmental conditions that ferns and mosses cannot Such plants can only survive in wet conditions As the planet evolved, plants needed to adapt to changing climatic conditions Seed plants represent a large group that are found in all forests and swamps of North America Gymnosperms Such plants produce seeds that are exposed Conifers The most common group of gymnosperms Otherwise known as evergreens They do not lose their leaves all at once
