2 ... 15 - Secondary growth

Question 1

Growth from secondary meristems result in…

Answer 1

increase in girth

Question 2

Growth from primary meristems result in

Answer 2

increase in length

Question 3

Define annual.

Answer 3

entire life cycle in single growing season (year)… limited to no secondary growth, rarely woody

Question 4

Define biennial.

Answer 4

life cycle in two growing seasons:
#1 ... root, basal rosette
#2 ... flower, fruit, seed

Question 5

Define perennials

Answer 5

Vegetative structures live year after year… common secondary growth and wood

Question 6

Secondary tissues produced from two meristems… called?

Answer 6

vascular cambium

cork cambium

Question 7

Secondary growth occurs in ___, not ___.

Answer 7

woody plants, NOT in monocots or herbaceous eudicots… primarily in stems/roots of woody plants

Question 8

Describe vascular cambium

Answer 8

major expansion of girth in stem through vascular tissue… secondary xylem and secondary phloem

Question 9

Describe cork cambium

Answer 9

forms new dermal protective layer (periderm)

Question 10

Vascular cambium composed of what two types of cell initials?

Answer 10

ray initials

fusiform initials

Question 11

Describe ray initials

Answer 11

produces radial or lateral transport system cells… isodiametric (small cells occur often in groups)

Question 12

Describe fusiform initials.

Answer 12

Produces axial or vertical vascular transport system cells… flat, elongated with pointed ends, highly vacuolar

Question 13

Define fascicular cambium

Answer 13

meristem cells within vascular bundle

Question 14

Define interfasicular cambium

Answer 14

meristems cells between vascular bundles

Question 15

Discuss formation of vascular cambium.

Answer 15

Inter/fascicular cambia form ring or cylinder…

divides when active in inner and outer directions:
inward -> new (secondary) xylem
outward -> new (secondary) phloem

Question 16

When is the vascular cambium active/inactive?

Answer 16

Active: spring to fall

Inactive: winder

Question 17

Annual growth rings

Answer 17

Growth most active in spring, slower in summer, cease in fall… result of alternating pattern of spring and summer woof

Can be used to determine ancient climatic conditions.

Question 18

Earlier wood typically has ___ vessels with ___ pores and fewer, small arrays

Answer 18

larger vessles

larger pores

Question 19

Late wood

Answer 19

comprised of dense, small cells.

Question 20

of annual rings…

Answer 20

varies in plant with age of that issue

Question 21

Describe sections of cork cambium.

Answer 21

Periderm - cork cambium + layers of cork cells.

Bark - consists of all tissues external to vascular cambium (including secondary phloem/periderm)

Question 22

Cork production?

Answer 22

cork lined with suberin wax… impermeable to water / gas

Question 23

Define lenticels.

Answer 23

gaps or weak ‘eruptions’ of parenchyma cells where cells can gases can diffuse

Question 24

Bark is composed of what?

Answer 24

all tissues outside vascular cambium

Question 25

Primary and secondary growth occur ___ but in ___ locations.

Answer 25

simultaneously, different locations

Question 26

heartwood

Answer 26

older, non-functioning xylem… darkened in appearance

Question 27

sapwood

Answer 27

younger functioning xylem, towards exterior.

Question 28

Secondary growth in roots

Answer 28

very similar to stems… formation of vascular cambium that encircles root. lacking in herbaceous eudi/monocots.