Plants Flashcards
1
Q
what is indeterminate growth
A
doesn’t stop growing at genetically predetermined point
2
Q
what are the 2 parts of the plant body
A
shoot system
root system
3
Q
what connects root and shoot systems
A
vascular tissue
4
Q
what direction can water be transported
A
roots to shoots.
5
Q
what direction can sugar be transported
A
both ways.
6
Q
when is absorption most efficient
A
when sa is large in relation to volume
7
Q
what is phenotypic plasticity
A
form is changeable depending on environmental conditions
8
Q
what is a herbaceous plant.
A
seed plant that lacks woody tissue
9
Q
what does perennial mean
A
live s multiple years
10
Q
why do even plants living next to each other have different root types
A
reduce competition
11
Q
how do spruce roots show phenotypic plasticity
A
dry: shallow roots
wet: deep roots
12
Q
how are mangrove roots special
A
function in gas exchange
13
Q
what is an adventitious root
A
root develops from shoot system
14
Q
what do stems consist of
A
nodes: where leaves are attached
internodes: segments between nodes
15
Q
what are leaves
A
appendages that project laterally and are photosynthetic organ
16
Q
what are nodes the site of
A
auxiliary bud
17
Q
what happens to auxiliary bud if conditions are good
A
bud grows into branch or into flowers
18
Q
why is variation of size and shape of. shoot system important
A
less competition for light harvesting
lets plants live in variety of habits
19
Q
what are the stem modifications
A
cacti, stolons, rhizomes, tubers, thorns
20
Q
how are cacti modified stems
A
stem enlarged to store water
21
Q
what is a stolon
A
grow horizontal along soil
produce adventitious roots and leaves at each node
new plants form at these nodes (asexual reproduction)
above ground
22
Q
what is a rhizome
A
stems that grow horizontally and produce plants at nodes
underground
23
Q
what is a tuber
A
underground swollen rhizome
function as carbohydrate storage
24
Q
what do thorns do
A
protect plants from herbivores
25
what are the parts of a leaf
blade: expanded portion
petiole: stalk of leaf
26
what does grass lack
petiole
27
what is a compound leaf
blade divided into leaflets
28
what is the defining feature of an individual leaf
presence of auxiliary bud where petiole joins stem
29
what is most common type of leaf in cold/dry places
needle like leaves
30
do leaves grow continuously
no
31
example of how leaves show plasticity
sun: thicker and and small SA (reduced water loss)
shade: thin and broad (high SA)
- maximizes photon absorption
32
what are the organelles unique to plants
cell wall
plasmodesmata
chloroplasts
vacuoles
33
what are the two types of cell walls and functions
primary cell wall: supports cell and defines shape
secondary cell wall: only some plants have it, and it is hard and rigid
34
what is a plasmodesmata
cytoplasm of adjacent cells is often connected by plasmodesmata
runs through membrane lined gaps in cell wall
35
what are chloroplasts
site of photosynthesis
36
what are vacuoles
store waste and sometimes diets it
stores water, nutrients, pigments, poisons
37
do plant cells change position once formed
no
38
what is simple tissue
contains one type of cell
39
what is a complex tissue
contains multiple types of cells
40
what does dermal tissue consist of
epidermis cells (outer most layer of cells)
included root hairs
41
what is primary function of dermal tissue
shoots: protect from water loss, pathogens, herbivores
roots: absorbing water and nutrients
42
is dermal tissue simple or complex
complex
43
what is the cuticle
one way epidermal cell protects plant
waxy layer on plant, reduces water loss, tho reduces gas exchange
44
what are stomata
pores on leaves
allow co2 to enter, o2 and water vapour to leave
controlled by guard cells
45
what are trichomes
hair like appendages made of specialized epidermal cells in shoot system
reflect sunlight (cool leaf)
reduce transpiration
provide barbs
store toxins
trap/digest insects
46
what is function of ground tissue
most photosynthetic and carbohydrate storage happens in ground tissue
responsible for specialized pigments, hormones, and toxins
plays large role in structural support
47
what does ground tissue consist of
parenchyma, collenchyma , sclerenchyma
48
what does totipotent mean
able to differentiate into any cell type
49
what is parenchyma
simple tissue
totipotent
- most versatile of ground tissue
in leafs: filled with chloroplasts (primary site of photosynthesis)
other organs: store starch
50
what is collenchyma
simple tissue
not rigid and can stretch, provides structure and flexibility
51
sclerenchyma
thick rigid secondary cell wall and thin primary
provides support once growth hs stopped
2 types: fibers and sclereids
52
what is function of vascular system
functions in support and long distance transport of water and dissolved nutrients
53
what is xylem made of
trachieds and vessel elements
54
are trachieds and vessel elements alive or dead at maturity
dead
55
what is phloem made of and are they alive at maturity
sieve tube elements
companion cells
alive at maturity
56
what does primary growth extend
plant body vertically
57
what is a meristem
populations of undifferentiated cells that retain ability to undergo mitosis
58
what is the apical meristem
located at tip of each shoot
extend plant body upward
responsible for primary growth
59
what kind of growth do most plants that do not contain woody tissue consist of
primary growth
60
what does apical meristem give rise to
ground meristem: gives rise to ground tissue
protoderm: gives rise to dermal tissue system
procambrium : gives ruse to vascular system
61
what is the root cap and its function
group of cells that protect root apical meristem
cells produced by meristem constantly replace cap
secretes slimy substance to make it easier for root to push through cell
62
what are the 3 distinct populations of cells behind root cap
->Zone of cellular division: contains apical meristem, proctoderm, ground meristem and procambrium
- where cells actively divide
-> zone of cellular elongation:
contains cells derived from primary meristem that increase length
-> zone of cellular maturation:
where older cells complete their differentiation into dermal, vascular, and ground tissues
63
how does zone of cellular elongation extend roots
cells in that zone take up water, expand, which pushes root cap through soil
64
where do lateral roots grow from
zone of cellular maturation
65
what does secondary growth do
increase width of plant
66
what is the function of secondary growth
increase amount of conducting tissues
provide structural support
67
what is the cambium
special type of meristem
responsible for secondary growth
68
what is the cambium
special type of meristem
responsible for secondary growth
69
how is cambrium different from apical meristem
forms cylinder that runs the length of trunk/ branch/ root
70
what growth produces wood
secondary growth
71
what are the types of cambria
vascular Cambrium
cork cambrium
72
how does plant get thicker
new cells produced inside plant push other cells out
73
what does the vascular cambium produce
secondary xylem and phloem, parenchyma , and sclerenchyma cells
74
what are the rays of a tree
parenchyma cells are formed in rows that radiate laterally
form living channel that transports water/nutrients across trunk
75
what accumulates as wood
secondary xylem
76
what happens to primary xylem
clogs and rots away
77
what is main function of cork cells
protect plant from pathogens
prevent water loss
since it produces layer of wax and a strong secondary cell wall containing lignin
78
what is bark made up of
secondary phloem
cork cambrium
cork cells
79
are cork cells alive at maturity
no
80
what happens to innermost xylem layers as tree matures/widens
innermost xylem dies, only most recent xylem transports water
81
what happens to xylem that no longer transports water
accumulates protective compounds secreted by other tissues
this darkens older portion of secondary xylem
- heart wood: darker inner region
-sapwood: lighter outer region
82
how do growth rings work
vascular cambium stops growing for portions of each year
dormancy takes place:
-cold climates: winter
-tropical: dry season
during dormancy xylem cells that are produced are smaller, thicker walled and darker (late wood)
when growth resumes: large thin walled lighter cells (early wood)
83
in what direction do solutes diffuse
high concentration -> low concentration
84
what directions does water diffuse
low solute concentration -> high
85
what is water potential
potential energy that water has compared to pure water
86
what direction does water potential go
high water potential -> low water potential
87
what are the factors that influence water potential
solute potential (tendency of water to move by osmosis)
pressure potential (tendency of water to move in response to pressure)
88
what does isotonic mean
solute concentration is same as as in cell
89
what does hypotonic
solute concentration lower in area surrounding cell than in cell
90
what is solute potential
tendency of water to move in response to differences in solute concentration
91
do solutions with high solute concentrations have high or low water potential
low water potential
92
what is turgor pressure
pressure inside cell
93
what is pressure potential
any kind of physical pressure on water
94
water potential in moist soil:
water in soil has low solute concentration so is lower than in roots so water heads to roots
higher water potential in soil
95
water potential in salty soils
high solute concentration
very low water potential n soil
96
water potential in dry soil
water doesn't flow freely and sticks to soil creating tension that lowers water potential
97
what type of air has lowest water potential
warm and dry
(evaporates faster)
98
what are the hypotheses for how water moves up plant
root pressure
capillary action
cohesion tension theory
99
what are 3 ways water enters roots
symplastic route: inside plasma membrane through symplast
transmembrane route: through water channels in plasma membrane
apoplastoc route: outside around plasma membrane
*though must pass through cell to enter xylem
100
what is the function of casparian strip
forms a water proof barrier between cells and xylem
forces water to go through cytoplasms of endodermal cells to reach vascular tissue
101
how does movement through root pressure work
at night stomata close, slowing movement of water
roots continue to accumulate ions
lowers water potential in xylem
water from surrounding cells rush into xylem
pushes water up
102
what is guttation
dew
in low growing plants enough water can be forced up through root pressure that droplets form at leaves
103
what is adhesion
molecular attraction between unlike molecules
104
what is cohesion
molecular attraction of like molecules
105
explain capillary action
water pulled up sides of tube through adhesion
water below follows through cohesion
since water molecules at surface have less other molecules to bond to their bonds are stronger causing water to be pulled up
106
how does cohesion tension theory work
water vapour diffuses through stomata
as water exists leaf water potential decreases so water is pulled from xylem (causes tension that pulls water)
water all the way through xylem get pulled up xylem because of cohesion
water is pulled from roots
107
what are adaptations that limit water loss
thick cuticle
stomata on underside of leaf, especially when inside deep pits and protected by trichomes
needle like leaves
open stomata at night (to collect / store co2) so they can close during day and retain ability to do photosynthesis
108
what is source
tissue where sugar enters phloem
109
what is a sink
tissue where sugar exits phloem
110
are sieve tube elements and companion cells alive at maturity
yes
111
what is girdling
removal of band of bark
removes strip of phloem, severing it, so tree dies
112
what are the steps of the pressure flow hypothesis
sucrose leave source (enter xylem through facilitated diffusion)
lots of sucrose in sieve tube so water potential lowers, which males water enter from xylem through osmosis
increased volume in sieve tube increases hydrostatic pressure which forces liquid down to sink (lower hydrostatic pressure)
why lower hydrostatic pressure at sink: sugar is actively transported into sink
- this lowers solute concentration and water diffuses back to xylem
- as a result volume is a lot smaller at sink
113
what does plant immune system consists of and how does arms race work
pattern triggered immunity (PTI) : sequence in bacterial protein is recognized by binding to surface of a receptor, triggering immune response
bacteria evolved proteins to avoid detection
Effector triggered immunity (ETI)
So bacteria evolve new effectors
....
114
what is a hypersensitive response
a mechanism to prevent the spread of infection
rapid cell death surrounding infection
115
what is a primary metabolite
function in essential metabolic processes
functions in growth and development
116
what are secondary / specialized metabolites
not essential functions
defence, attraction of pollinators, inhibiting growth of nearby plants
117
what does constitutive mean
always produced/ present
opposite of induced
118
what are terpenes
toxic to plant cells
stored in specialized hair/ducts/glands/etc..
act by smell/tasting bad , being sticky, plugging wounds on plants (amber)
119
what is a cell-autonomous response
both signal and response produced in same cell
120
what is non-cell-autonomous response
signal produced in one cell and response in another
121
what does gibberllins (GA) regulate
flowing, dormancy, stem elongation
122
what does inhibiting GA do
makes plants smaller
123
what does spraying GA do to plant
make fruit and plant larger
124
what is auxin involved in
root/vein patterning
fruit development
apical dominance
photo-gravi-tropism
leaf formation
125
what is apical dominance
when apical bud is activated lateral bud is dormant
when apical bud id cut off, lateral bud doesn't receive auxin anymore (in apical bud) growth is no longer inhibited and lateral buds grow
126
what does cytokinins regulate
transitions in cell cycle
can be used to increase bushiness/yield, delay deterioration of crops
micro-propogation
127
what are the changes as in phase shift from juvenile to adult vegetative phase
leaf shape
rooting ability
128
what regulates phase changes
mRNA
129
does mRNA influence flowering
no it only induces a competency to flower
130
what causes plant to shift from vegetative to reproductive phase
environmental triggers
away from equator: temperature and photoperiod (day length)
131
what determines photo period
season and latitude
132
what is a day neutral plant
flowering isnt regulated by day length
133
what does a short pulse of red light at night do
induce growth in long day
inhibit growth in short day
134
where is flowering inducing signal transmitted from/to
leaves to meristem
