Lecture 13 - Plant Growth and Development Flashcards
(96 cards)
1
Q
what does basic morphology of vascular plants reflect
A
evolution as organisms that draw nutrients from below and above ground
2
Q
what do plants take up from below ground
A
- water
- minerals
3
Q
what do plants take up from above ground
A
- CO2
- light
4
Q
three basic organs evolved in plants
A
- roots
- stems
- leaves
5
Q
two systems in plants
A
- root system
- shoot system
6
Q
rely on sugar produced by photosynthesis in the shoot system
A
roots
7
Q
rely on water and minerals absorbed by the root system
A
shoots
8
Q
generate new cells for primary and secondary growth
A
different meristems
9
Q
plant can growth throughout its life
A
indeterminate growth
10
Q
perpetually embryonic tissue and allow for indeterminate growth
A
meristems
11
Q
some plant organs cease to grow at a certain size
A
determinate growth
12
Q
two main types of meristems
A
- apical meristems
- lateral meristems
13
Q
shoot apical meristem
A
young leaves
14
Q
lateral meristems
A
- vascular cambium
- cork cambium
15
Q
located at the tips of roots and shoots
A
apical meristems
16
Q
growth in apical meristems
A
primary growth (elongate)
17
Q
add thickness to woody plants
A
lateral meristems
18
Q
growth in lateral meristems
A
secondary growth
19
Q
adds layers of vascular tissue called secondary xylem and secondary phloem
A
vascular cambium
20
Q
secondary xylem
A
wood
21
Q
replaces the epidermis with periderm, which is thicker and tougher
A
cork cambium
22
Q
cork cambium replaces epidermis with what
A
periderm
23
Q
what do meristems give rise to
A
- initials
- derivatives
24
Q
- aka stem cells
- remain in the meristem
A
initials
25
become specialized in mature tissues
derivatives
26
protects the apical meristem in the root as the root pushes through soil
root cap
27
three zones of cells behind the root tip
zone of
1. cell division
2. elongation
3. differentiation, or maturation
28
what is produced in the primary growth of roots
1. epidermis
2. ground tissue
3. vascular tissue
29
in angiosperm roots, the __ is a vascular cylinder
stele
30
in most dicots, what is the appearance of xylem and phloem
xylem = starlike
phloem = between the "arms"
31
in many monocots, what does the root look like
core of parenchyma cells surrounded by rings of xylem and phloem
32
- mostly parenchyma cells
- fills the cortex, the region between the vascular cylinder and epidermis
ground tissue
33
region between the vacular cylinder and epidermis
cortex
34
innermost layer of the cortex
endodermis
35
regulates passage of substances from the soil into the vascular cylinder
endodermis
36
- where the lateral roots arise from
- outermost cell layer in the vascular cylinder
within the pericycle
37
formation of lateral root
1. origin in pericycle
2. growth though cortex
38
dome-shaped mass of dividing cells at the shoot tip
shoot apical meristem
39
where do leaves develop from
leaf primordia along sides of apical meristem
40
develop from meristematic cells left at the bases of leaf primordia
axillary buds
41
the closer an axillary bud is to teha ctive apical bud, the more __ it is
inhibited
42
where the axillary buds are released if the shoot tip is removed or shaded
apical dominance
43
where do lateral shoots develop
axillary buds on stem's surface
44
secondary growth is characteristics of what
gymnosperms and many dicots, not monocots
45
where does secondary growth occur in a plant
stems and roots
46
produce tissues that consists the secondary growth
- vascular cambium
- cork cambium
47
where does the vascular cambium develop from
undifferentiated parenchyma cells
48
where is the vascular cambium located
- outside pith and primary xylem
- inside of primary phloem and cortex
49
what do elongated initials produce
1. tracheids
2. vessel elements
3. xylem fibers
4. sieve-tube elements
5. companion cells
6. axially oriented parenchyma
7. phloem fibers
50
what do shorter initials produce
1. vascular rays
2. radial files of parenchyma cells
51
accumulates as wood and consists of tracheids, vessel elements, and fibers
secondary xylem
52
- has thin cell walls to maximize water delivery
- formed in spring
early wood
53
- has thick-walled cells and contributes more to stem support
- formed in late summer
late wood
54
- visible where late and early wood meet
- can be used to estimate a tree's age
tree rings
55
the analysis of tree ring growth patterns and can be used to study past climate change
dendrochronology
56
inner layers of secondary xylem that no longer transports water and minerals
heartwood
57
outer layers that still transport materials through the xylem
sapwood
58
give rise to cork cells that accumulate to the exterior
cork cambium
59
what do cork cells deposit
waxy suberin
60
cork cambium and the tissues it produces
periderm
61
found in the periderm that allow for gas exchange between living stem or root cells and the outside air
lenticels
62
consists of all the tissues external to teh vascular cambium, including secondary phloem and periderm
bark
63
produce the plant body
- growth
- morphogenesis
- cell differentiation
64
describes the effect of environment on development
developmental plasticity
65
ireversible increase in size
growth
66
development of body form and organization
morphogenesis
67
process by which cells with the same genes become different from each other
cell differentiation
68
cell division in meristems increase the potenial for growth
increasing cell number
69
accounts for the actual increase in plant size
cell enlargment
70
new cell walls form in a plane __ to the main axis of cell expansion
perpendicular
71
microtubules become concentrated into a ring called the __ __
preprophase band
72
what does the preprophase band predict
future plane of cell division
73
leaf growth results from what
combination of transverse and longitudinal cell divisions
74
gene that affects longitudinal divisions
tangled-1 gene
75
determines cell fate
1. symmetry of cell division
2. distribution of cytoplasm between daughter cells
76
signals a key event in development
asymmetrical cell division
77
condition of having structural or chemical differences at opposite ends of an organism
polarity
78
results from a symmetrical first division
gnom mutant of _Arabidopsis_ (thale cress)
79
how do plant cells grow rapidly and cheaply
intake and storage of water in vacuoles
80
where do plant cells expand primarily
plant's main axis
81
- restrict the direction of cell elongation
- found in the cell wall
cellulose microfibrils
82
devlopment of specific structures in specific locations
pattern formation
83
two tyeps of hypotheses that explain the fate of plant cells
1. lineage-based mechanisms
2. position-based mechanisms
84
propose that cell fate is determined early in development and passed on to daughter cells
lineage-based mechanisms
85
propose that cell fate is determined by final position
position-based mechanisms
86
experiments suggest that it is established late in development and depends on cell position
cell fate
87
affect the number and placement of appendages in animal embryos
Hox genes
88
- plant homolog of Hox genes
- does not affect the number or placement of plant organs
KNOTTED-1
89
KNOTTED-1 is important where
development of leaf morphology
90
depends on gene expression, but is determined by position
cellular differentiation
91
how is positional information communicated
through cell interactions
92
where does gene activation or inactivation depend on
cell-to-cell communication
93
cell remains hairless if this is expressed
GLABRA-2
94
developmental phases plant pass through
phase changes
95
where do phase changes occur
within shoot apical meristem
96
most obvious morphological changes
leaf size and shape
