Lab #6

Question 1

Stems of dicotyledons contain _____ and ______ and why?

Answer 1

Cortex and Pith

Because there is a ring of vascular bundles present

Question 2

Each vascular system consists of a region (or strand) of ____ and ____

Answer 2

Xylem and Phloem

Question 3

Difference between xylem and phloem in stems vs roots

Answer 3

• Stems: xylem and phloem are joined together in bundles

- Roots: xylem and phloem are in seperate strands

Question 4

Shoots consist of (2)

Answer 4

• leaves attached at nodes, at which branches may form, with internodes between

• dependant on stem, especially the form of thenodes, internodes, and branches

Question 5

A. Vines (3)

Answer 5

• elongated internodes (typical of vines)

- weak stems that depend on support to stay errect

Question 6

B. Shrub (3)

Answer 6

• branched
• shorter internodes
• self supporting

Question 7

C. Tree (2)

Answer 7

• wide variety

- the essance of a tree is in jts secondary growth from a vascular cambium

Question 8

D. Rosette (2)

Answer 8

• short internodes

- partly underground stem

Question 9

E. Tuber (2)

Answer 9

• thickened, fleshy, underground stem

- scale leaves

Question 10

F. Runner (2)

Answer 10

• horrizontal

- above ground stem rooting at nodes

Question 11

G. Stolon

Answer 11

-horizontal, underground stem

Question 12

H. Rhizome

Answer 12

• horizontal, underground stem

Question 13

I. Bulb

Answer 13

• bulbs

- swollen, fleshy leaves

Question 14

J1. Cladophylls

Answer 14

Flattened, leaf-like stems that closely resemble leaves

Question 15

J2. Thorns

Answer 15

Lateral branches that have grown out, then stopped

Question 16

J3. Tendrils

Answer 16

Specialized branches

Question 17

Apical Meristems (Stems)

Answer 17

• region of cell proliferation

• all stems grown from apical meristems
• apical metistem similar to root apical meristem
• BOTH are true meristems (permanently embryonic)
• protoderm, ground meristem, procambium are recognizable
• histogenesis & organogenesis is recognizable
• leaf primordia (leaves arise)
• nodes and internodes develop in stem
• vascular, ground, and dermal tossue systems also appear

Question 18

True Meristems

Answer 18

• some cells are always dividing
• cells are always undifferentiated
• thin walled
• isodiametric
• no cell types have begun to form (not even primary meristematic)

Question 19

Histogenesis

Answer 19

Region of tissue differentiation

Question 20

Organogenesis

Answer 20

Organ development

Question 21

Axial System

Answer 21

Cells oriented parallel to the axis; derived from fusiform initials of the cambium

Question 22

Ray System

Answer 22

The rays

Question 23

Tangential Section

Answer 23

Longitudinal section made perpendicular to the radius. Rays appear lens-shaped

Question 24

Radial Section

Answer 24

Longitudinal section parallel to the radius. The rays appear as flat sheets

Question 25

Transverse Section

Answer 25

Cross section

Question 26

Growth Layer

Answer 26

(Annual ring) secondary xylem formed in one year, consisting of early wood ajd late wood

Question 27

Early Wood

Answer 27

Less dense wood produced first in spring

Question 28

Late Wood

Answer 28

More dense wood produced later in summer

Question 29

Heartwood

Answer 29

Dead, non-functional wood commonly dark colored

Question 30

Sapwood

Answer 30

Contains living parenchyma cells, active in conduction, light colored and toward outside of trunk

Question 31

Resin Ducts

Answer 31

Canals lined with parenchyma which secrete resin

Question 32

Circular Bordered Pit

Answer 32

Complex pit of conifers containing a border and thickened torus, occurs o. Tracheids

Question 33

Librriform Fiber

Answer 33

Thick walled fiber with minimal pitting

Question 34

Perforation

Answer 34

A hole in the cell wall

Question 35

Pit

Answer 35

Thin place or depression in a cell wall

Question 36

Ring Porus

Answer 36

Growth layers having large diameter in the early wood and very small diamete pores in the late wood

Question 37

STUDY

Answer 37

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