Exam 1 Flashcards
1
Q
Herbaceous tissue of the primary plant body develops from the…
A
apical meristem
2
Q
in woody species, ____ ____ are produced in the stem and root from other meristems
A
secondary tissue
3
Q
what produces wood containing secondary xylem?
A
vascular cambium
4
Q
What produces bark containing secondary phloem and cork?
A
Cork Cambium
5
Q
The secondary tissues constitutes the plant’s ____ body
A
secondary
6
Q
Woody plants are thus a _____ of primary and secondary tissue
A
combination
7
Q
When is a herbaceous plant’s conducting capacity set?
A
After a portion of stem or root is mature
8
Q
Woody plants become wider ____ ____ by accumulation of wood and bark, giving them a greater conducting capacity
A
every year
9
Q
What are disadvantages to secondary growth (i.e., being woody)
A
- Greater need for defenses, both structural and chemical to survive for a long time
- must use energy and nutrient resources for winterizing their bodies in temperate climates
- Expensive metabolically to construct wood and bark
10
Q
When will woody plants produce?
A
Not until they’re several years old
11
Q
True or False? All woody trees and shrubs (including gymnosperms) descended from one group of ancestral woody plants that arose approx. 370 million years ago
A
True
12
Q
____ is an ancient trait and has evolved infrequently
A
wood
13
Q
most evidence indicates that the first flowering plants were woody (____ is ancestral.
A
Woody
14
Q
_____ of wood to the herbaceous condition is the ____ condition
A
- Loss
- Derived
15
Q
True secondary growth (wood) occurs in:
A
- Many eudicots
- all gymnosperms
- but never in ferns or monocots
16
Q
_____ (e.g., grasses, lilies, orchids) initially evolved from a woody ancestor but later lost the ability to produce woody tissues
A
Monocots
17
Q
What is the meristem that produces the wood of the secondary plant body
A
Vascular cambium
18
Q
Facts about vascular cambium
A
- it originates as a layer of cell that lies between the xylem and phloem of a vascular bundle in a plant stem
- in herbaceous plants, these cells do not divide (usually)
- In woody plants, this region becomes meristematic
19
Q
To form a complete vascular cambium that completely encircles the plant stem, 2 regions of cells must becomes meristematic. What are those regions?
A
- Fascicular cells
- Interfascicular cells
20
Q
What occurs between xylem and phloem within a vascular bundle
A
Fascicular
21
Q
What occurs between vascular bundles
A
Interfascicular cells
22
Q
Once developed, the ____ ____ will consist of a single layer encircling the stem that is capable of continued division
A
Vascular Cambium
23
Q
The vascular cambium contains two types of cells
A
- fusiform initials-long and narrow
- ray initials- short, cuboid
24
Q
_____ _____ of the vascular cambium are long, tapered cells.
A
Fusiform initials
25
Fusiform initials divide to produce...
(to the interior) the elongate cells of xylem (wood):
-tracheids
- vessel elements
- fibers
- parenchyma
Also divide to produce (to the exterior) elongate cells of phloem:
- sieve cells
- sieve tube members
- companion cells
- fibers
- parenchyma
26
fusiform initials of the vascular cambium divide longitudinally with a _____ _____ ( parallel to the meristem) to produce 2 elongate cells:
periclinal wall
1. one cell remains a fusiform initial (of the meristem)
2. The other differentiates into either a cell of secondary xylem or secondary phloem
27
_____ _____ cells (produced to the interior) increase greatly in diameter in growth, pushing the vascular cambia cells outward.
- this begins to cause stress on the cambial cells that can't keep up
Secondary xylem
28
vascular cambium cells must occasionally divide longitudinally by _____ _____ (perpendicular to the cambium's surface).
anticlinal walls
- this allows the cambium to add cells and increase in diameter and keep up with the increasing girth of the woody layer underneath
29
____ ____ in the vascular cambium are short and cube-shaped, unlike the elongate fusiform initials.
Ray initials
30
Ray initials divide to form xylem or phloem ______ that function:
-in storage
- or as albuminous cells (in gymnosperms)
Parenchyma
31
within the vascular cambium: fusiform initials may occur depending on the tree species:
-in regular horizontal rows (_____ ____)
-irregularly, without any horizontal pattern (_____ _____)
1. storied cambium
2. nonstoried cambium
32
____ ____ are grouped together in short vertical rows.
- one cell wide (____)
- two cells wide (____)
- many cells wide (_____)
1. ray initials
2. uniseriate
3. biseriate
4. multiseriate
33
vascular cambium _____ has large regions of just fusiform initials or just ray initials; it's always mixed
never
34
what type of cells are there?
1. Secondary xylem
2. axial (vertical) system
3. radial (horizontal) system
35
what is (wood) contains all of the cell types that occur in primary xylem?
secondary xylem
36
what is derived from the fusiform initials
axial (fusiform) system
37
what develops from the ray initials
radial (horizontal) system
38
The 'axial system' (up and down; vertical) contains:
1. tracheary elements
2. fibers
3. parenchyma
39
(tracheids and vessels) what carries out vertical conduction of water through the wood
tracheary elements
40
what provides strength
fibers
41
what contains a large amounts of fibers
hardwoods
42
what contains a few or no fiber
softwoods
43
what serves as a temporary reservoir of water
parenchyma
44
most gymnosperms ("softwoods") contain ____ tracheids in their axial systems
only
45
fibers and parenchyma cells are ____ and ____
sparse and absent
46
in woody angiosperms the ____ ____ contains only parenchyma
radial systems ('rays')
47
ray parenchyma cells:
-store carbohydrates and other nutrients
- conduct material over short distances radially
48
for woody plants in temperate regions and dry seasons:
growth rings occur in wood due to the differential growth of early (spring) wood versus late (summer) wood.
- spring wood has high proportion of wide vessels or tracheids.
- summer wood has fewer vessels, or narrower, thick-walled tracheids
- no growth during winter
49
together, early wood and late wood make up 1-year's growth an, _____ ____ ____
annual (growth) ring
50
wood with vessels found mostly in early wood is called...
ring porous
51
ring porous species include:
-oaks
- hickories
- ashes
52
wood with vessels found throughout is...
diffuse porous
53
diffuse porous species include:
red maple
black gum
54
the center of a log is the _______
heartwood
55
heartwood is almost always _____, _____, and more _____ than the outer wood (____), which is lighter colored.
- darker
- drier
-fragrant
- sapwood
56
heartwood is denser, contains less water, is more aromatic, and has better acoustic properties than sapwood
....
57
heartwood forms when:
- tracheary elements (tracheids and vessel elements) of older portions of wood no longer function in water transport; they get old and worn out
- but the cellular spaces they leave behind would be ideal passage ways for fungal hyphae and bacteria to reside and cause rot
- THEREFORE: the tree seals off this old vascular tissue in the wood
58
heartwood also forms when:
-a tylosis forms inside the old tracheary elements
- this is an intruding plug from an adjacent (living) parenchyma cells.
- xylem parenchyma cells (XP) produce compounds that inhibit growth of bacteria and fungi.
- this makes the cells dark and aromatic
- eventually, the tracheary elements are completely plugged up and filled with defense compounds.
- when the parenchyma cells die, they also leave behind dark, highly decay-resistant cells
- so both the parenchyma and tracheary elements contribute to the heartwood
59
in ____ _____ _____, differential wood strength is necessary to provide support.
- the resulting wood is called ___ ____
-laterally spreading branches
- reaction wood
60
in _____, additional growth occurs mostly on the upper side of a branch, which is known as ____ ______
- angiosperms
- tension wood
61
tension wood is enriched with ______ fibers enriched with _____
- gelatinous
- cellulose
62
____ form reaction wood enriched with lignin on the ______ of the branch which is known as _____ ____
- conifers
- underside
- compression wood
63
what is the most expensive wood
Black Wood
64
the ____ ____ produced by the vascular cambium is responsible for conduction up and down the stem (or root) by the _____ xylem and phloem
- axial system
- secondary
65
_____ ____ into phloem are formed just the same as for xylem rays: after all, they are formed by the same cuboid initials in the vascular cambium
- the rays consist of parenchyma ____ ____
-horizontal rays
- storage cells
66
in a few species, the cork cambium may produce some tissues to the inside to form parenchyma layer known as _____
Phelloderm
67
the layers of cork cells (and the phelloderm, if present) are called _____
periderm
68
the cork cambium is _____ and not _____ in place
- irregular
- fixed
69
____ cork cambium forms in younger secondary phloem closer to the vascular cambium
new
70
what are all tissues of a woody stem that is exterior to the vascular cambium
Bark
71
what is secondary phloem part of bark
inner bark
72
what is the dead, cork tissue produced by the cork cambium
outer bark
73
cork cells become filled with waxy suberin and defense comounds; and then die:
- this makes the periderm _____ and ____ ____. which is great protection from herbivores and xylovores (wood eaters)
- waterproof
- chemically inert
74
bark is a rich source of a diversity of substances:
- building materials and textiles
- medicinals, flavorings, and drugs
75
what is the process of removing the outermost layers of a woody stem in a ring?
girdling
76
what is the traditional method of killing trees without felling them?
girdling
77
girdling removes the ____ (cork layer), ____ ____, _____ ____ layers, and ____ ____ (which separates easily from the underlying secondary xylem)
- periderm
- cork cambium
- secondary phloem
- vascular cambium
78
Complete girdling means ____ is completely removed which means portions of tree above starve and die
phloem
79
downsides of cork:
- the impermeability of cork blocks the absorption of oxygen
- thereby preventing respiration of internal tissues
- bark becomes permeable to oxygen when special rounded cork cells are produced
- these allows air spaces to develop between in the outer layers of cork
80
regions of cork develop as visible _____
lenticels
81
roots have 4 main functions:
1. anchoring the plant firmly to a substrate
2. absorbing watering and minerals from soil
3. producing hormones
4. storing carbohydrates in the winter
82
most eudicots have _____
taproots
83
what is a single large root that develops from the radicle (embryonic root)
taproots
84
what is initially produced from the tap root
lateral roots
85
most monocots have a ____ ____ ___
fibrous root system
86
the major roots in monocots don't arise from the _____
radicle
87
roots grow from an ___ ___ at the root tip
apical meristem
88
the initial apical meristem was a part of the ____ in the seed
embryo
89
the root apical meristem is protected by a ____ ____
root cap
90
cells in what region undergo expansion?
zone of elongation
91
the ____ ____ ___ is a region in which many of the epidermal cells extend out as narrow trichomes
root hair zone
92
new lateral roots emerge from the primary root from ____ the root hair zone
behind
93
the ___ ___ is a protective structure produced by the underlying meristem.
- it is continually being worn away due to abrasion during growth through soil, so it continuously needs to be replaced
root cap
94
cells of the root cap contain large starch granules called ____ that sink to the bottom of the cell.
statoliths
95
the position and distribution of statoliths in cap cells influence the flow of the hormone ____ upward in the root
auxin
96
for a root extending horizontally, the statoliths cause an ___ in ____ on the underside of the root
- increase
- auxin
97
root cap cells secrete copious amounts of ____, a complex polysaccharide rich in carbohydrates and amino acids
mucigel
98
mucigel:
- lubricates passage of the root through the soil
- chemically causes soil to release nutrients
- fosters rapid growth of beneficial soil bacteria.
- mucigel bacteria, in turn, further helps in uptake of nutrients
99
the zone around the root tip of a plant constitutes the _____
rhizosphere
100
root apical meristem has 3 zones:
1. the zone that yields new root cap cells
2. a quiescent center which is not mitotically active, functions as a reservoir of cells that can rebuild the meristem if it becomes damaged
3. the upper zone that yields the cells of the growing root
101
what is the region of the root beyond the meristematic region
zone of elongation
102
zone of maturation is marked by:
1. the production of root hairs growing by the epidermal cells
2. differentiation of tissues
103
what are cells that transfer water and minerals from the epidermis
root cortex
104
transport of water through the cortex may be:
1. symplastic
2. apoplastic
105
what are cell to cell through shared cytoplasm connected by plasmodesma
symplastic
106
what transports on the exterior of cells along the cell walls
apoplastic
107
endodermis
- is one cell layer thick and is the inner-most layer of cortex
- marks the boundary between the cortex and vascular region
- radial cell walls of the endodermis are rich in waterproof lignin and suberin; these constitute the Casparian strip
- the casparian strip tightly controls the flow of water and minerals that may pass through the vascular tissue
108
casparian strips control flow by cutting off the ____ pathway, forcing ____ transport of water and minerals.
- apoplastic
- symplastic
109
materials can only pass to vascular tissues ____
symplastically
110
the casparian srip forces symplastic flow with 3 different options:
1. apoplastic flow is blocked.
2. apoplast to symplast
3. symplastic flow
111
what is irregular cylinder of parenchyma cells lying underneath the endodermis
pericycle
112
-what is the central cylinder of tissue, interior to the endodermis
- consists of pericycle, xylem, and phloem.
vascular stele
113
above the maturation zone, in the older parts of the root, big changes happen:
1. root hairs whither away
2. secondary cambia emerge to produce wood and bark of the root, just as in the stem
114
vascular cambium-->
root wood
115
cork cambium -->
root bark
116
as in stems, the root vascular cambium produces:
- secondary xylem to the inside (original primary xylem remains in the center)
- secondary phloem to the outside (original primary phloem gets pushed to the exterior)
117
____ on roots is produced by a cork cambium _____ that arises in the pericycle
phellogen
118
Most woody roots have high storage capacity.
- Storage occurs in parenchyma cells of the root found in:
-Ray parenchyma cells (horizontal)
- axial parenchyma cells (vertical)
- both are products of the root vascular cambium
119
the wood of a root is different than the wood of a stem in that:
1. it is mostly parenchyma
2. these are few vessels and no fibers
120
the root parenchyma stores:
1. carbohydrates (produced by photosynthesis in the summer)
2. water
3. proteins
121
storing materials in the roots has many disadvantages:
1. roots are less visible as food for most foragers
2. root surroundings are more stable and protected from environmental fluctuations than aboveground parts
122
the ____ that we consume is secondary growth (wood) modified for high capacity storage
taproot
123
what root is described:
- tall, plate-like roots of some tropical trees
- upper side grows more rapidly than other parts of the root
- brace the trunk from being blown over by wind or in thin soils
buttress roots
124
what roots is described:
- aerial roots of orchids have a specialized epidermis layer called a velamen
- many orchids are epiphytic.
- they grow on trees, with roots high up in the canopy.
- waterproof velamen prevents water loss in dry conditions
velamen roots of epiphytes
125
what roots are described:
-many monocots such as lillies, daffodils, and onions that have bulbs and corms produce ____ _____.
- these add stability and depth control of the bulbs
- cortex cells are able to shorten and expand radially (contract).
- this pulls the bulb deeper into the soil
contractile roots of monocots
126
what roots are described:
- ____ are highly modified roots of parasitic plants
- _____ penetrate the epidermis and cortex (or bark layers) then continue to grow until they make contact with the host's vascular tissue
- ____ roots are able to:
- attach the parasitic plant to the host.
- rapidly penetrate the host in order to tap into vascular tissue.
- either stems or roots may be attacked.
haustoria of parasitic plants
127
what's an epiphytic hemiparasitic shrub on oak
mistletoe
128
what are symbiotic associations between the roots of seeds plants and soil fungi?
- fungi gain carbohydrates stored in the roots.
- fungal hyphae aid the plant in phosphorus uptake from soil
Mycorrhizae (fungi)
