Plant Anatomy Unit 1 Chapter 6 Lesson 1

The Importance of Plants Without plants, life on earth could not exist Plants are the primary source of food for humans and animals

The Importance of Plants cont. Plants also: Provide oxygen Provide shade Supply us with medicines Renew the air Slow down the wind Hold soil in place Are a home for wildlife Furnish building materials and fuel

Parts of the Plant Most plants are made up of four basic parts: Leaves Stems Roots Flowers (these later become fruit or seeds)

Roots Usually underground – not visible Functions: Anchor the plant and hold it upright* Absorb water and minerals from the soil & conduct them to the stem* Store large quantities of plant food* Propagate or reproduce in some plants * = essential to all plants

Roots on the Inside Very similar to a stem Older roots of shrubs & trees have: Phloem on the outside (old phloem is bark) Cambium layer Xylem (wood) on the inside

Phloem Carries manufactured food down to the root for food storage Xylem Carries water and minerals up to the stem

Roots on the Outside Different from a stem On a stem, the terminal bud initiates growth On a root, the root cap Root cap continuously makes new cells that protect the root as it pushes into the soil

Root External Structure Behind the root cap are root hairs Root hairs become side roots that branch out as the root grows older Absorb moisture and minerals which are conducted up to the larger roots and the stem

Roots as Crops Cash crops Carrots Beets Radishes Sweet Potatoes

Root Propagation Plants with tuberous roots: Dahlia Peony Sweet Potato Are propagated by separating the root clump or by rooting spouts from the root

Types of Root Systems Fibrous Root System vs. Tap Root System

Which root system is easier to transplant? Fibrous roots or tap roots? Answer: Fibrous roots Why? Because when plants are dug up out of the ground, a greater % of the fibrous roots system is saved.

If a root loses to many root hairs while being transplanted, the plant will die. Larger roots only conduct & store water, nutrients, and food Root hairs absorb moisture from the ground

Important “Root”words Root System All of the root parts of a single plant collectively Primary Root First root sent from a germinating seed Absorbs water and nutrients for growing seedling Anchors seedling in the ground Secondary Roots Small branches that form off of the primary root

Important “Root”words Root cap Group of cells at the end of a root that protect it from the coarse soil as it pushes through to grow Adventitious root Roots that begin growth from a stem or leaf Commonly found on corn plants Basal rooter Plants that will produce roots at the base of the stem when a cutting is taken

Important “Root”words Root tuber Enlarged food-storage root with adventitious shoots that develop These shoots produce adventitious roots to produce a new plant