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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 .
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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