Chapter 35 Flashcards
1
Q
Primary growth
A
Extension of shoots and roots
2
Q
Why do plants exhibit indeterminate growth?
A
they have meristems
3
Q
Meristems
A
populations of undifferentiated cells that are able to continuously divide and produce new cells
4
Q
populations of undifferentiated cells that are able to continuously divide and produce new cells
A
Meristems
5
Q
Extension of shoots and roots
A
Primary growth
6
Q
Apical meristems
A
located at the tip of each root and shoot (RAM and SAM)
7
Q
What happens as cells in the apical meristem divide, enlarge, and differentiate
A
root and shoot tips extend
8
Q
During primary growth, cells produced by the meristem give rise to three…
A
primary meristems
9
Q
Primary meristems
A
Produce the mature tissues of the plant
10
Q
Three types of primary meristems
A
- Protoderm
- Ground Meristem
- Procambium
11
Q
Tissue system that forms from protoderm
A
Dermal tissue
12
Q
Tissue system that forms from ground meristem
A
ground tissue
13
Q
Tissue system that forms from procambium
A
Vascular tissue
14
Q
What is RAM protected by?
A
root cap
15
Q
What does the root cap do?
A
sense gravity and determine direction of growth
16
Q
What does the root cap secrete
A
mucigel
17
Q
Mucigel
A
helps lubricate root tip as it moves through the soil
18
Q
Zone of cellular division
A
production of new root cells
19
Q
Zone of cellular elongation
A
composed of cells that are dividing to increase in length
20
Q
What is the zone of cellular elongation responsible for?
A
movement of roots in soil (push RAM through soil)
21
Q
Zone of differentiation (maturation)
A
where older cells complete differentiation into distinct cell types
22
Q
Where are the youngest cells during root growth?
A
Near the root tip
23
Q
What does 1st degree root growth produce?
A
epidermis, ground tissue, and vascular tissue
24
Q
Ground tissue (root system)`
A
mostly parenchyma cells - cortex
25
Cortex
region between vascular cylinder and epidermis
26
Function of the cortex
extracellular diffusion of water, minerals, and O2 from root hairs
27
Endodermis (root system)
innermost region of cortex
28
What does the endodermis surround
vascular cylinder
29
What does the endodermis function in?
regulating passage of substances from soil into vascular system
30
Eudicot root structure
1. Dermal Tissue System
2. Ground Tissue System
3. Vascular Tissue System
31
Dermal Tissue System (Eudicot root structue)
Epidermis
32
Ground Tissue System (Eudicot root structue)
1. cortex (contains starch grains - purple)
| 2. endodermis (surrounds vascular cylinder/column)
33
Vascular Tissue System (Eudicot root structue)
1. Pericycle
2. Xylem Tissue
3. Phloem Tissue
34
Pericycle (vascular tissue system)
production of lateral roots
35
Xylem tissue (vascular tissue system)
conducts water
36
Phloem tissue (vascular tissue system)
conducts photosynthates (between the 'arms')
37
Dermal Tissue System (monocot root structure)
Epidermis
38
Ground Tissue System (monocot root structure)
Cortex, endodermis, and pith
39
Vascular tissue system (monocot root structure)
1. vascular cylinder
2. pericycle
xylem and phloem for rings around core of parenchyma cells (pith)
40
pericycle
outermost cell layer of vascular cylinder just inside endodermis
41
SAM
dome-shaped mass of dividing cells at shoot tip
42
Leaf primordia
site of leaf development
43
When does leaf primordia take place?
during SAM
44
What happens during leaf primordia
within buds, young leaves are close together. Shoot elongation results from lengthening of internodes
45
Apical dominance
Axillary buds remain dormant due to inhibition by apical bud
46
What does branching result from?
releasing apical dominance (pruning/herbivory)
47
What does 1st degree growth in shoots give rise to?
dermal, ground, and vascular tissues
48
In stems, vascular tissues are...
grouped into vascular bundles that run length of stem
49
Dermal Tissue System in primary shoot system in eudicots
epidermis
50
Ground tissue system in primary shoot system in eudicots
1. pith
2. cortex
3. mostly parenchyma cells
4. collenchyma cells below epidermis
4. sclerenchyma cells
51
Pith in ground tissue system of eudicot shoot
in center
52
cortex in ground tissue system of eudicot shoot
external to vascular tissue
53
Collenchyma cells below epidermis
provide strength during growth
54
Sclerenchyma cells in eudicot shoot system
provide strength to stems no longer elongating
55
Vascular tissue system in eudicot shoot system
vascular bundles arranged in a ring
- xylem
- phloem
- vascular cambium
56
Dermal tissue system in monocot stem
epidermis
57
Ground tissue system in monocot stem
- no formal cortex
| - similar to dicots (regarding tissue/cell types)
58
Vascular tissue system in monocot stem structure
vascular bundles scattered throughout stem
59
Dermal tissue system in leaves
- epidermis (covered by cuticle)
| - guard cells (surround opening called stomata - for gas exchange)
60
Ground tissue system in eudicot leaf structure
1. Mesophyll (middle leaf)
2. Palisade mesophyll
3. Spongy mesophyll
61
Mesophyll (ground tissue system in eudicot leaf structure)
made up of parenchyma cells that function in photosynthesis
62
Palisade mesophyll (ground tissue system in eudicot leaf structure)
elongated parenchyma cells on upper part of leaf
63
Spongy mesophyll
loosely arranged parenchyma cells with air spaces for gas exchange
64
Ground tissue in monocot leaf structure
only spongy mesophyll
65
Vascular tissue system of leaves
continuous with that of stem
- xylem
- phloem
- veins enclosed by bundle of sheath
66
Xylem of leaves
brings H2O in for psyn
67
Phloem of leaves
transports photosynthates to other parts of plant
68
Veins enclosed by bundle sheath does what?
regulates movement of substances between vascular tissue and mesophyll
69
Vascular system of eudicots
have net venation
70
Vascular system of monocots
have parallel venation
71
What does secondary growth increase?
the width of the plant body via lateral meristems
72
What do lateral meristems/secondary growth function in?
increasing the amount of conducting tissue available and provides structural support for extensive primary growth
73
What does secondary growth produce
wood
74
Where does secondary growth occur
in species that have a cambium in addition to apical meristems
75
Cambium (secondary meristem/lateral meristem)
1. made of thin layers of meristematic cells that form cylinders that run the length of a root or stem
2. can divide to increase width of roots and shoots
3. two types (vascular and cork)
76
Apical meristem (first degree growth)
1. form dome-shaped cell clusters localized in root and shoot tips
2. cells divide to extend root and shoot tips
3. two locations: root tips (RAM) and shoot tips (SAM)
77
Vascular cambium
1. produces secondary phloem to the outside
| 2. produces secondary xylem to the inside
78
Initials oriented perpendicular to the stem/root produce...
vascular rays
79
Vascular rays
connect secondary xylem and phloem
80
Do we observe second degree growth in monocots?
No
81
Indeterminate growth
Plants never stop growing
82
Plant hierarchial organization
system
organs
tissues systems/tissues
cells
83
Shoot system
stems and leaves (organs)
84
Root system
Roots (organ)
85
Characteristics of root system
1. underground
2. anchor plant to soil
3. absorb water and minerals from soil
4. conducts water and minerals to shoot
5. stores carbohydrates and other reserves
86
Characteristics of shoot system
1. above ground biomass
2. harvests light and carbon dioxide to produce sugars
3. elevate reproductive organs
4. exports photosynthates (sugar and other carbohydrates) to root system
87
Characteristics of leaves
1. vast majority of photosythesis occurs here
2. exchange gases with atmosphere
3. dissipate heat
4. defend against herbivores and pathogens
88
How do roots rely on the shoot system?
they rely on sugar produced via photosynthesis in shoot system
89
How do shoots rely on the shoot system?
they rely on water and minerals absorbed by the root system
90
Primary root (first root)
emerges from seed embryo
91
Lateral branches
extend from primary root (increase ability to anchor/aquire nutrients)
92
Root hairs on elongating roots
increase root surface area and are primary site of nutrient absorption
93
Where are root hairs found?
on the tip of the root
94
Where does most absorption take place?
Tip of the root
95
Taproot system
1. primary root becomes taproot
2. prevents toppling over
3. absorption is primarily funcion of lateral roots
96
Where are taproots often seen?
In dicots
97
Fibrous root system
primary root dies early and does not form a taproot
98
Adventitious roots
Many small roots emerge from stem (part of fibrous root system)
99
Where is the fibrous root system often seen?
in monocots
100
What are root systems of different plants...
are adapted to environment and minimize competition
101
What can roots change in response to?
environmental conditions
102
Major organs of the shoot system
stems and leaves
103
What does the stem consist of?
nodes and internodes
104
Apical buds
elongate stems
105
Axillary buds
develop branching
106
What do shoot systems do?
adapt to the environment and minimize competition
107
What happens if you remove a terminal/apical bud?
apical dominance (lateral branches begin to grow)
108
Blade
wide, expanded, flat portion of the leaf
109
Petiole
the stalk of the leaf that joins leaf to stem
110
All organs are made up of _____ that form ______.
tissues; tissues system
111
Tissue type to dermal tissue system
epidermis
112
Tissue types of vascular tissue system
xylem and phloem
113
Tissue types to ground tissue system
parnchyme, collenchyma, and sclerenchyma
114
Functions of the dermal tissue system
to protect the plant from water loss, disease, and herbivores
115
What is the dermal tissue system made up of?
Epidermal tissue
116
What cell types does the epidermal tissue contain?
Epidermal cells, guard cells (surround stomata), trichomes
117
Epidermal cells
secrete the cuticle that covers the shoot system, protectsleaves, and reduces water loss
118
Stomata
allow carbon dioxide to ender photosynthetically active tissues
119
What does the stomata consist of?
two guard cells which change shape to open or close the pore
120
Trichomes
protective hairlike structures made up of specialized epidermal cells
121
Funcions of the vascular tissue system
support and long distance transport of water and nutrients
122
What is the vascular tissue system collectively called?
the stele (or vascular cylinder/column)
123
Xylem tissue
contain tracheids and vessel elements
124
Phloem tissue
contain sieve-tube elements and companion cells
125
What does xylem tissue do?
conduct water and nutrients from root to shoot (also side to side)
126
All xylem cells are...
dead at maturity and filled with fluid instead of cytoplasm
127
Xylem cells - tracheids
- long and slender
- tapered ends
- water moves through pits
- spindle shaped
128
Xylem cells - vessel elements
- short and wide
- aligned end to end (joined at perforation plate)
- water flows through perforation plates (and pits)
129
What does phloem tissue do?
conduct sugars (photosynthates) throughout plant body (not uniderectional like xylem)
130
Phloem cells are...
alive at maturity
131
Phloem cells - sieve tube elements (members)
1. long, thin cells
2. no nuclei and most other organelles (easier to transport nutrients...)
3. sugars and nutrients transported from cell to cell through sieve plates
132
Phloem cells - companion cells
1. don't conduct material
2. assist with loading and unloading carbohydrates and nutrients from solution inside sieve tube members
3. their organelles serve the sieve-tube members as well
133
Functions of the ground tissue system
photosynthesis, carbohydrate storage, support, and short-distance transport
134
Parenchyma cells
1. thin primary cell walls
2. primary site of photosythesis (leaves)
3. store starch (roots)
4. mature cells are alive and still able to divide (wound repair)
135
Collenchyma cells
1. thickness of primar cell wall varies (some area of secondary wall thickening)
2. can elongate even when mature (are alive)
3. Funcion in "flexible" support (grouped in strands)
4. Found in elongating stems andn petioles of leaves
136
Sclerenchyma cells
1. thin primary wall
2. can't elongate
3. funcion in support (many dead at maturity)
4. produce thick secondary cell wall containing lignin
137
Two types of sclerenchyma cells
fibers, sclereids
138
Fibers
extremely elongated for support
139
Sclereids
relatively short for protection
