lecture 20 - lignophytes, wood

Question 1

turgor pressure

Answer 1

holds plants upright, doesn’t require any extra energy, cannot survive if no water

Question 2

what two forces move water through a plant?

Answer 2

root pressure: pushes up
transpiration: pulls up

Question 3

which maian lineages are tracheophytes?

Answer 3

lycophytes, ferns, gymnos, angios

Question 4

lignin

Answer 4

chemical impregnated in cell walls, hydrophobic and bacterial resistant

Question 5

tracheids

Answer 5

dead water conducting cells, secondary wall with lignin

Question 6

fibers

Answer 6

long cells, can be dead or alive, secondary wall with lignin

Question 7

vessel elements

Answer 7

long dead cells, 2nd wall with lignin, wider than tracheids for increased water flow, no end walls, perforations in vessels called pits allow lateral movement, water moves through non-lignified area

Question 8

pro-tracheophytes

Answer 8

tracheids without lignin (homeophyton & aglaophyton)

Question 9

as stem diameter increases, plant height ___

Answer 9

increases

Question 10

stele

Answer 10

portion of the plant body consisting of the primary vascular tissues

Question 11

collenchyma

Answer 11

cells are long living cells with uneven primary cell walls
ex: petiole of celery leaves

Question 12

vessel tubes

Answer 12

formed in the vascular bundles of most angiosperms, composed of linear series of elongated vessel elements which conduct water, minerals, other materials

Question 13

4 types of tracheids

Answer 13

S type - rhyniopsida (rhynia)
G type - early lycophytes (zosterophylls)
P type - early euphyllophytes (trimerophytes)
seed plant - recent euphyllophytes

Question 14

what do the differentiations of tracheid type mean?

Answer 14

these are examples of ancestral tracheids which looked different and functioned differently than extand tracheophytes

Question 15

simple vs complex tissues

Answer 15

refers to amount of cell differentiation and aggregation of cells

Question 16

how does secondary vascular meristem change vascular tissue arrangement?

Answer 16

the bundles fuse into concentric circles

Question 17

what did secondary vascular meristem do for plants?

Answer 17

allowed plants to grow laterally/horizontally not just vertically

Question 18

primary tissues

Answer 18

produces by primary meristem

Question 19

meristem

Answer 19

clusters composed of small, undifferentiated, embryonic cells

Question 20

types of apical meristemin the root (3)

Answer 20

protoderm
ground meristem
procambium

Question 21

protoderm

Answer 21

type of apical meristem, produces dermal tissue

Question 22

ground meristem

Answer 22

type of apical meristem, prod. ground tissue

Question 23

procambium

Answer 23

type of apical meristem, prod. vasvular tissue

Question 24

how many times did tracheids evolve?

Answer 24

multiple times

Question 25

when tracheids evolved, leaves were present/not present and these plants conducted psynth in ___ so that this structure had to balance ___

Answer 25

not present, stems, mechanical support/water conduction/psynth

Question 26

early tracheid plants w/out leaves had a conflict:

Answer 26

between water-conducting-tissue and water-conducting-mechanical tissue, conflict between psynth and mechanical support, became necessary to transfer functions to specialized organs, new psynthetic organs developed

Question 27

primary/apical meristems are located:

Answer 27

at the apex of the shoot and root systems

Question 28

vascular cambium is bifacial which means:

Answer 28

it grows from both sides, phloem on outer side and xylem on inner side

Question 29

phloem cell types:

Answer 29

sclerenchyma, parenchyma, food conducting cells

Question 30

xylem cell types:

Answer 30

sclerenchyma, parenchyma, lignified water conducting cells

Question 31

primary vs secondary meristem

Answer 31

primary: up down growth
secondary: lateral growth, only in woods plants

Question 32

how did secondary vascular cambium form a ring?

Answer 32

formation of the interfascicular cambium joining the fascicular cambium of two vascular bundles

Question 33

from pith to bark, what is order of vasc. tissues?

Answer 33

innermost: primary xylem –> secondary xylem –> vascular cambium –> secondary phloem –> primary phloem

Question 34

periclinal growth

Answer 34

growth parallel to surface

Question 35

anticlinal growth

Answer 35

growth perpindicular to surface

Question 36

second lateral secondary meristem is the:

Answer 36

cork cambium

Question 37

what is cork cambium’s purpose?

Answer 37

since the accumulation of new layers increases the radius and hence the circumference of the vascular ring, the outer layer will stretch and break apart and therefore must be replenished, cork accumulates as a secondary dermal tissue, must be continuously replaced

Question 38

cork cambium is bifacial and produces:

Answer 38

cork (cork cambial cells) outward, parenchyma cells inward, these compose the periderm

Question 39

are cork and bark the same thing?

Answer 39

no, the periderm (which is what the cork cambium produces) is only the outer bark, the bark as a whole also includes phloem (which is prod. by vascular cambium)

Question 40

what lineage are cycads?

Answer 40

gymnosperm

Question 41

gymnosperm vs angiosperm vascular tissue

Answer 41

gymn: tracheids
angio: vessel elements (more efficient)

Question 42

cross section vs radial section vs tangential section

Answer 42

radial: both lines
cross section: xylem holes, rays lines
tangential: xylem lines, rays holes