Ch. 6 Stems Part 2

Question 1

Name tissue pattern in stems

Answer 1

steles

Question 2

steles

Answer 2

central cylinder of primary xylem, primary phloem, and pith(if present)

Question 3

Name the three types of stele tissue patterns

Answer 3

protostele, siphonosteles, and eusteles

Question 4

Protostele

Answer 4

sold core, phloem surrounds xylem
* In primitive seed plants (whisk ferns, club mosses, ferns)

Question 5

Siphonosteles

Answer 5

tubular with pith in center
* Common in ferns

Question 6

Eusteles

Answer 6

discrete vascular bundles
* Flowering plants
* Conifers

Question 7

Name the tree types of seed leaves

Answer 7

cotyledons, dicotyledons, monocotyledons

Question 8

cotyledons

Answer 8

seed leaves attached to embryonic stems
 Store food needed by young seedling

Question 9

dicotyledons

Answer 9

flowering plants that develop from seeds having two cotyledons (dicots)
 Typically taproots (some exceptions)

Question 10

monocotyledons

Answer 10

flowering plants that develop from seeds with single cotyledon (monocots)
 Typically fibrous (some exceptions)
 Example: grasses
 Note: most do not have vascular or cork cambium, making them uncapable of secondary growth

Question 11

Describe Herbaceous dicotyledon stems

Answer 11

annual plant
 Usually green, herbaceous plants (non-woody tissue types)
 Mostly monocots, some dicots
 Largely primary tissues

tissue patterns include herbaceous dicot and vascular cambium

Question 12

herbaceous dicot tissue

Answer 12

discrete vascular bundles arranged in cylinder

Question 13

vascular cambium

Answer 13

arises between primary xylem and primary phloem
* Adds secondary xylem and phloem

Question 14

Describe woody dicotyledon stems

Answer 14

o Wood = secondary xylem
o Differences in wood: Vascular cambium and cork cambium that are active all year (some tropical trees) produce ungrained, uniform wood

Includes structures such as vascular rays, heartwood, and sapwood

Question 15

vascular rays

Answer 15

consist of parenchyma cells, function in lateral conduction of nutrients and water
* Xylem ray: part of ray within xylem
* Phloem ray: part of ray through phloem

Question 16

Heartwood

Answer 16

dark wood at center of tree

Question 17

Sapwood

Answer 17

still conducts water, close to cambium lighter than heartwood

Question 18

Seasonap production of wood: during and after spring

Answer 18

o Spring: Relative large vessel elements of secondary yxlem produced (spring wood); Fewer tracheids

After spring: Fewer smaller, vessel elements in proportion to tracheids and fibers; More trahceids; (summer wood)

Question 19

What does xylem growth in one year show?

Answer 19

annual ring indicates age and climate
 Bulk of tree trunk consists of annual rings of wood