Stems

Question 1

Stem Functions

Answer 1

• Support and elevation of leaves
• Conduction
• Storage of starches and water

Question 2

Shoot

Answer 2

Stem with associated leaves and buds

Question 3

Node

Answer 3

Point of stem where leaves attach

Question 4

Internode

Answer 4

Region of stem b/w 2 adjacent nodes

Question 5

Tunica

Answer 5

Outer covering of meristem

Question 6

Corpus

Answer 6

Inner layers of meristem

Question 7

Apical meristem structure of stems

Answer 7

Tunica (Outside)

Corpus (Inside)

Question 8

Buds

Answer 8

Embryonic shoot

-Terminal and auxillary

Question 9

Terminal Buds

Answer 9

Buds at tips of branches

Question 10

Primary growth during spring

Answer 10

• Internodes lengthen out (at same time)
• Increase stem length
• Leaves behind terminal bud scale scar

Question 11

Auxillary (Lateral) Buds

Answer 11

Buds found in axil of stem and leaf

-Grow into branches, flowers or inflorescences

Question 12

Primary growth in stems

Answer 12

• Occurs when buds lengthen out
• Not divided into zones
• Occurs due to simultaneous elongation of cells at the internodes of a bud

Question 13

Dicot Stems

Answer 13

• Cortex and pith
• Vascular bundle ring
• Secondary growth possible

Question 14

Monocot Stems

Answer 14

• Ground tissue not divided into cortex and pith
• Scattered vascular bundle
• No secondary growth

Question 15

Vascular bundle structure

Answer 15

• a strand of vascular tissue with phloem to outside and xylem inside
• Often with fibers
• Bundle cap
• Bundle sheath

Question 16

Bundle Cap

Answer 16

Fibers above phloem

Question 17

Bundle Sheath

Answer 17

Fibers surrounding whole bundle

Question 18

Epidermis function and structures (2)

Answer 18

• Prevent dessication–Cuticle

- Allow for gas exchange–Stomata w/ guard cells

Question 19

Ground Tissue System function and structures (4)

Answer 19

• Photosynthesis–chloroplasts
• Gas exchange–aerenchyma
• Storage–amyloplasts
• Support/Protection–collenchyma

Question 20

Open vascular bundle

Answer 20

• No bundle sheath
• Left over procambuim
• Secondary growth

Question 21

Closed vascular bundle

Answer 21

• Bundle sheath
• No left over procambium
• No secondary growth

Question 22

Bicollateral vascular bundle

Answer 22

• Internal phloem
• No bundle sheath
• Left over procambium
• Secondary growth

Question 23

Protoxylem Lacuna

Answer 23

Closed bundle

-hole ripped in xylem

Question 24

Rhizome

Answer 24

Horizontal, underground stem

• bears leaves and nodes
• bears adventitious roots
• Iris

Question 25

Tuber

Answer 25

• Swollen, thickened portion of rhizome
• Storage or water and starch
• Potato

Question 26

Bulb

Answer 26

• Short, underground stem
• Surrounded w/ fleshy leaves or leaf bases
• Onion

Question 27

Succulent Stem

Answer 27

Thick, fleshy stem

• Used for water storage
• Often photosynthetic

Question 28

Thorn

Answer 28

Sharp, hard stem used for protection

-buds become thorns

Question 29

Tendrils

Answer 29

Support organs that twist around another structure

-can be modified stems or leaves (look for buds)

Question 30

Poison

Answer 30

• 3 leaflets
• Liana: woody vine
• Conducting and non-conducting adventitious roots
• Urushiol: chem compound