1. Parts of Plants and their Functions

2. Objectives Note contributions of plants to the life cycle on earth
List and describe the purpose of the four main parts of plants
Explain process of photosynthesis
Explain process of respiration
Explain major structural differences between dicot and monocot stems
Describe process of pollination

3. Importance of Plants Without plants, life on earth would not exist
Plants are the source of food for humans and animals, directly or indirectly
Plants produce oxygen and are the major producers
Plants help keep us cool, renew the air, slow wind, hold soil in place, shelter wildlife, beautify space, perfume the air, furnish building materials, and fuel

4. ROOTS

5. Root Functions Anchor the plant and hold upright
Absorb water and minerals from the soil and conduct them to the stem
Store large quantities of plant food
Propagate or reproduce some plants
The first three are essential to all plants

6. Root Structure The internal structure of a root is similar to a stem
Older roots of shrubs and trees have a phloem on the outside, a cambium layer, and xylem (wood) on the inside
A phloem is the old outer layers of corklike bark

7. The phloem carries manufactured food down to the root for food and storage
The xylem carries water and minerals up to the stem

8. External structures of roots are different form stems
Roots have a root cap that produce new cells which lubricate a path and protect the cap as new roots push its way through the soil

9. Behind the root cap are many root hairs which absorb moisture and minerals for larger roots and the stem
Side roots of increasing size form as the plant grows older

10. Roots are important agricultural cash crops
Carrots, beets, radishes and sweet potatoes are roots
Roots also serve for propagation
Dahlia, peony, and sweet potato have tuberous root clumps that can be separated will sprout new roots and plants

11. Fibrous Roots Fibrous root plants are very easy to transplant
Roots are smaller, shorter and more compact, allowing more roots to be saved

12. Tap Roots Tap root systems have longer and fewer roots
Tap roots are usually cut off during transplanting which loses root hairs and the ability absorb water and nutrients
Tap roots will conduct and store water and nutrients but not absorb it

13. Roots will move toward moisture in the soil
Central roots grow downward because of the force of gravity
This is know as geotropism and is controlled by the root tip