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