1. Plant Anatomy
Unit 1
Chapter 6
Lesson 2

2. Stems Stems have 2 main functions: The movement of materials
Movement of water and minerals from roots up towards the leaves
Movement of manufactured food from the leaves down to the roots
Support of the leaves and reproductive structures
Flowers and fruit or seeds

3. Stems cont. Stems are also used for: Food storage Reproductive methods
Irish Potato
Reproductive methods
Stem cuttings or grafting
Green stems manufacture food just like leaves

4. Stems on the Outside
Lenticels
Breathing pores

5. Stems on the Outside cont.
Bud scale scars
Indicate where a terminal bud has been located
The distance between two scars represents one year of growth
Leaf scars
Show where leaves were attached

6. Unique Stems Irish Potato & Gladiolus Very different stems
Stems are used for food storage and plant reproduction
                            

7. Stems on the Inside Vascular system
Water and minerals travel up the XYLEM
Manufactured food travels down the PHLOEM
Comparative to animal circulatory system

8. Dicots
Dicots (2 cotyledons - seed leafs) the xylem and phloem are separated by the cambium
The cambium produces new cells
Grow continually because the cambium builds new xylem and phloem cells
Trees are a perfect example!
Sap = new xylem
Heartwood = old, inactive xylem
Tree bark = old, inactive phloem

10. Monocots One cotyledon (seed leaf) Grasses, corn No outside cambium
Vascular bundles that contain xylem & phloem
Cells don’t increase in number, they grow in size (won’t keep growing like a tree)

12. Monocots vs. Dicots

13. What do we do with Stems? Food Building Materials Asparagus
Irish Potato
Celery
Building Materials
Wood

14. Key Stem Words Cambium Bud Bud scales Terminal bud
Where cell division takes place
Bud
Structures containing undeveloped leaves, stem, or flowers
Bud scales
Cover and protect the bud
Terminal bud
Large bud at the tip of a stem

15. Key Stem Words Apical meristem Auxins Lateral buds Apical dominance
Primary growing point of the stem
Auxins
Hormones that influence the growth of a stem
Lateral buds
Bus found on the sides of the stem
Apical dominance
Auxin influence causes the lateral buds closest to the apical meristem from developing so that the growth can be concentrated on an upward point vs. an outward point.

16. Key Stem Words Bulb Corm Rhizome Stem tuber
Short, flattened stems that bear fleshy food storage leaves
Corm
Short, swollen underground stem
Rhizome
Underground horizontal stem
Stem tuber
Swollen tips of the rhizome

17. Key Stem Words Stolon Horizontal stem that is above ground
Produces roots at tip or nodes to produce a new plant asexually