3.2 Plants

Characteristics of plants

• Are large, multicellular, eukaryotic organisms

• Perform photosynthesis

• Cell walls are composed of cellulose

• Are sessile

BRYOPHYTES

• Have a protective cuticle and stomata for gas exchange

• Do NOT have vascular tissue or true leaves, roots, or seeds.

• Are generally small because they do not contain vascular tissue

• Needs an environment that is occasionally wet

Example: Sphagnum moss

LYCOPHYTES & PTEROPHYTES

• Have vascular tissues composed of lignin

• Lignin builds strength in cell walls which allows the plant to grow to greater heights.

• Are seedless

• Have large leaves

• Have simple roots and stems

Example: horsetails and ferns

Ligin

Type of organic polymer found in the cell walls of plants that provides structural support and rigidity.

GYMNOSPERMS: The Conifers

• Seed plant

• Reproduce with specialized cones that produce pollen grains and ovules

• Most have needle or scale-like leaves

• Narrow leaves with thick cuticles help with water retention

Examples: pine, spruce and cedar

ANGIOSPERMS: The Flowering Plants

• Produce seeds within a specialized structure called a fruit.

• Reproduce using flowers