Plant form and function Flashcards
(117 cards)
1
Q
Main roles of leaves (4)
A
- Intercept light
- Gas exchange
- Dissipate heat
- Defense
2
Q
When are plant organs formed?
A
After germination
3
Q
What is the main goal of the plant body?
A
To maximise survival in changing environments
4
Q
Meristem
A
Localised regions of ongoing cell division that enable growth during post-embryonic development
5
Q
Apical meristems
A
- Lead to primary growth (new organs, basic plant form, length)
6
Q
Where are apical meristems located?
A
At the growing tip of shoots and roots
7
Q
Axillary buds
A
Secondary meristems that are formed in the axils of leaves
8
Q
What do axillary buds become?
A
Apical meristems of branches
9
Q
Lateral meristem
A
A meristem that thickens the roots and shoots of woody plants. The vascular cambium and cork cambium are lateral meristems
10
Q
What are meristems?
A
Localised regions of ongoing cell division that enable growth post embryonic development
11
Q
SAM
A
Shoot apical meristem; forms stems and leaves
12
Q
RAM
A
Root Apical Meristem; extends the root system
13
Q
Role of the root cap
A
To protect the apical meristem
14
Q
Primary plant growth
A
Lengthening roots and shoots of the plant
15
Q
Secondary plant growth
A
Adds girth to stems and roots in woody plants
16
Q
In which plants do primary and secondary growth occur simultaneously?
A
Woody plants
17
Q
What is plasticity?
A
Plant’s ability to alter itself in
response to its environment
18
Q
What are the 3 main organs of a plant?
A
- Roots
- Stems
- Leaves
19
Q
What is the role of the root system?
A
- Anchor the plant
- Absorb minerals and water
- Store organic nutrients
20
Q
What is the name of the first root to emerge from the germinating seed?
A
Primary root
21
Q
What is the name of a root that arises from the pericycle of an established root?
A
Lateral root
22
Q
What is the name of a main vertical root that develops from an embryonic root and gives rise to lateral roots?
A
Tap root
23
Q
What part of the root are tiny extensions of a root epidermal cell, growing just behind the root tip?
A
Root hairs
24
Q
What is the role of root hairs?
A
Increase the surface area for absorption of water and minerals
25
What are Adventitious roots?
Roots arising from any organ other than a root
26
What is the role of Buttress roots?
To support the trunk
27
What is the role of Prop roots?
To support tall plants
28
What is the role of Storage roots?
To store food and water
29
What is the role of Pneumatophore roots?
To obtain oxygen
30
What is the role of Strangling roots?
To take over
31
What are the main roles of plant stems?
- Elongate
- Orient shoot to maximise light capture
- Elevate reproductive structures
- Photosynthesise (a bit)
32
What do stems consist of?
- **Vascular tissue**
- Alternating system of nodes and internodes that support the leaves and reproductive structures
33
What is a stem Node?
A point along the stem of a plant
at which leaves are attached
34
What are Rhizomes?
Underground stems for storage
35
What is an internode?
A segment of a plant stem between the nodes
36
What is an axillary bud?
A structure that has the potential to form a lateral shoot or branch. Appears in the angle form between a stem and a leaf
37
What is an Apical bud?
A bud at the tip of a plant stem
38
What are tubers?
Enlarged rhizomes for storage
39
What are Stolons?
Horizontal stems that have asexual reproduction
40
What are the main roles of leaves?
- Intercept light
- Gas exchange
- Dissipate heat
- Defence
41
What is a leaf margin?
The edge or boundary of a leaf blade
42
What is a leaf blade?
The flattened portion of a typical leaf
43
What is a leaf vein?
Vascular bundle in a leaf
44
What is a leaf midrib?
The central, primary vein of a leaf
45
What is a petiole?
The stalk of a leaf, which joins the leaf to a node of a stem
46
What are simple leaves?
Leaves with a single, undivided blade
47
What are compound leaves?
Leaves that have a blade consisting of multiple leaflets
48
Do leaflets have axillary buds at their base?
No
49
What are tendrils?
Modified leaves for support
50
What are spines?
Modified leaves for defence
51
What are Carnivorous leaves?
Modified leaves that trap insects for nutrients
52
What are storage leaves?
Modified leaves that store food
53
What are the three fundamental tissue types that all plant organs have?
1. Dermal
2. Vascular
3. Ground
54
What is the role of dermal tissue in plants?
- Prevents physical damage and invasion by pathogens
- Stops excess water loss
55
What is the role of ground tissue in plants?
- Storage
- Photosynthesis
- Support
- Short-distance transport
56
What is the role of vascular tissue in plants?
- Transport
- Mechanical support
57
What is Parenchyma?
A relatively unspecialised plant cell type that carries out most of the metabolism, synthesises and stores
organic products, and develops into a more differentiated cell
58
What is Collenchyma?
A flexible plant cell type that occurs in strands or cylinders that support young parts of the plant without restraining growth
59
What is Sclerenchyma?
A rigid, supportive plant cell type usually lacking a protoplast and possessing thick secondary walls strengthened by lignin at maturity
60
What is the plant body designed for?
To maximise survival in changing environments
61
Plant form and function are ....
Tightly connected
62
True or false; plants are sessile
True
63
What types of environmental conditions can plants sense?
Temperature, humidity and
light intensity
64
Which of the following is/are true of plant organisational patterns?
A) Each organ has a specific arrangement of the three tissue systems
B) These patterns vary between plant types (monocots vs eudicots) and developmental stages
C) Both A and B
C
64
65
What do Meristematic regions enable?
Recovery
66
What is Vascular cambium?
Secondary xylem and phloem
67
What is cork cambium?
Secondary dermal tissue
68
What do lateral meristems drive?
Secondary growth (thickening) in woody plants
69
What do apical meristems drive?
Primary growth (lengthening of the plant)
70
What are the 3 zones in primary plant growth?
1. Zone of cell division
2. Zone of elongation
3. Zone of differentiation
71
What occurs in the zone of cell division?
New cells are produced
72
What occurs in the zone of cell elongation?
Where most growth occurs, cells elongate
73
What occurs in the zone of cell differentiation?
Cells mature, become distinct types
74
Where do all leaves and stems come from?
SAM
75
What does vascular cambium produce?
Secondary xylem (wood) and secondary phloem
76
True or false: In woody plants primary and secondary growth occur simultaneously
True
77
What does cork cambium produce?
Thick waxy cells
78
What is secondary xylem in woody plants?
Wood toward the inside of the stem or root
79
What is secondary phloem in woody plants?
Inner bark (towards the outside)
80
What does the Cork cambium replace in woody plants?
The epidermis
81
What is the outer bark produced by cork cambium called?
Periderm
82
Phase changes are ...
Morphological changes that arise from transitions in shoot apical meristem activity
83
What accounts for about 90% of a plant cell's expansion?
Water uptake stored in a large central vacuole
84
What is a feature unique to monocot stems?
Vascular bundles are scattered throughout
85
What are fractals?
Repetitive patterns in plant growth
86
If you pound a nail into a tree one metre off the ground and come back to find it in 20 years, it will be ....
One metre off the ground and more deeply embedded in the tree
87
Why does pinching off the top of a plant make it bushier?
Removing the apical meristem stimulates growth in the axillary buds, thus making the plant bushier.
88
What is the main difference between a primary root and a lateral root?
Lateral roots enhance the ability of the root system to anchor the plant and acquire resources from the soil
89
What are sieve-tube elements?
Sugar-conducting structures of plants
90
In woody plants, the vascular cambium initial is ________.
mitotically active and divides to form an inner layer of secondary xylem and an outer layer of secondary phloem
91
What are preprophase bands?
Bands that determine the location where the cell plate will form during cell division
92
A Hox gene homolog in plants is called ____ and is important in ____
KNOTTED-1; leaf morphology
93
Most of the photosynthesis in plants takes place in specialised _____ cells called the __
parenchyma; mesophyll
94
Which gene is root hair formation regulated by?
GLABRA-2
95
Water-conducting cells of plants are called _______
Tracheids and vessel elements
96
What is the physical property that predicts the direction in which water will flow?
Water potential
97
How might roots react when they encounter a region of the soil that is low in nitrates?
Minimise branching
98
What is root pressure attributable to?
The accumulation of minerals in the vascular cylinder
99
What type of root architecture allows plants to grow taller?
Taproots
100
What is the plant hormone that is produced by roots and leaves during times of drought?
Abscisic acid
101
What does the protonne pump do?
Pumps H+ out of the cell
102
What will happen to a plant cell placed in a solution with a higher water potential?
It will gain water and become turgid
103
How is the movement of sugar into the phloem accomplished?
Cotransport with H+
104
What happens to K+ when guard cells become flaccid?
They are lost to neighbouring cells
105
True or false; the Casparian strip is impermeable to water
True
106
As the Casparian strip is impermeable to water, water and minerals cannot pass directly into the root xylem of the vascular cylinder except by
Crossing a selectively permeable membrane of an endodermal cell
107
Which nutrient deficiency causes reduced internode length?
Zinc
108
Which nutrient deficiency causes chlorosis at the tips of older leaves?
Nitrogen
109
What are the 3 types of meristem?
1. Apical
2. Axillary bud
3. Lateral
110
What are the key features of lateral meristems?
- Form cylinders of dividing cells that run along the length of stems and roots
- Include the vascular cambium and cork cambium
- Drive secondary growth (thickening) in woody plants
111
Where are lateral meristems located?
Running along the length of stems and roots
112
Vascular cambium and Cork cambium are both types of .....
Lateral meristem
113
What does Vascular cambium produce?
Secondary xylem (wood) and secondary phloem
114
What does Cork cambium produce?
The outer bark (periderm) of woody plants
115
Where are axillary buds located?
The axils of leaves (where leaves attach to stems)
116
What can axillary buds develop into when activated?
Branches
