Lecture 22: Secondary Growth

Question 1

what are the two kinds of lateral meristems?

Answer 1

cork cambium
vascular cambium

Question 2

what is the function of vascular cambium?

Answer 2

adds layers of secondary xylem/phloem

Question 3

what is secodnary xylem?

Answer 3

wood

Question 4

the vascular cambium is typically bifacial, what does this mean?

Answer 4

secondary xylem grows inward, secondary phloem grows out… vascular cambium is producing tissue from both directions!

Question 5

what is the main function of the cork cambium?

Answer 5

replaces epidermis with periderm

Question 6

“periderm” refers to all layers of outer bark… what are these components?

Answer 6

cork, cork cambium, phelloderm

Question 7

secondary growth occurs ____ elongation in mature stems

Answer 7

after

Question 8

primary and secondary growth occur ____

Answer 8

simultaneously

Question 9

secondary growth does not happen in ___

Answer 9

monocots

Question 10

grasses/cereals/palm trees are examples of…

Answer 10

monocots

Question 11

which structure provides lateral transport in secondary vasculature?

Answer 11

rays

Question 12

in what order do the cork cambium and vascular cambium develop? and why?

Answer 12

cork cambium develops after the vascular cambium because it is limited in its growth

Question 13

lateral meristems shut down in ____ but come back in the _____… why?

Answer 13

winter
spring, because its growing season

Question 14

one growth ring = ….

Answer 14

one growing season

Question 15

what kind of cells make up the vascular cambium?

Answer 15

undifferentiated parenchyma cells

Question 16

the ____ is wholly responsible for the production of secondary vascular tissue

Answer 16

vascular cambium

Question 17

in what order do these structures fall… vascular cambium, pith, cortex, primary xylem, primary phloem

Answer 17

pith, primary xylem, vascular cambium, primary phloem, cortex

Question 18

more secondary _____ is produced than secondary ____

Answer 18

xylem
phloem

Question 19

____ has thin cell walls, bigger cells, and occurs in the spring

Answer 19

early wood

Question 20

___ have thick cell walls and small cells, in the late summer

Answer 20

late wood

Question 21

____ has uniform texture

Answer 21

soft wood

Question 22

___ have variable texture and colour variations in dicots

Answer 22

hard wood

Question 23

___ is “living”, lighter in colour

Answer 23

sap wood

Question 24

___ is non-living, darker in colour

Answer 24

heart wood

Question 25

conifers (gymnosperms) have which kind of wood?

Answer 25

soft wood

Question 26

what are some of the traits of softwood?

Answer 26

small amount of parenchyma, dominated by tracheids, have resin canals for sap

Question 27

angiosperms have what kind of wood?

Answer 27

hard wood

Question 28

what are some traits of hardwood?

Answer 28

vessels/tracheids/parenchyma are equal in amount, more variation in wood structure, have fiber tracheids

Question 29

do monocots make wood?

Answer 29

no