Chapter 35 - Plant Structure Flashcards
(94 cards)
1
Q
From what point do the roots and shoots of vascular plants grow?
A
They grow from the tips (apices)
2
Q
What are the functions of roots?
A
- anchor the plants
- penetrates soil to absorb water and minerals
- can exert huge forces as they grow
- adapted to living on land; roots are how they get water on land
3
Q
What are the functions of shoots?
A
- stems are the scaffolding for positioning leaves
- leaves are the main site of photosynthesis; in the leaf tissues
- flowers, fruits, and seeds formed on shoot
- opposite direction of roots
4
Q
What is the repeating unit of shoots?
A
internode, node, leaf, and axillary bud
5
Q
Where is the Axillary bud located?
A
between the branch and the internode
6
Q
Where is the Internode located?
A
in between branches
7
Q
Where is the node located?
A
where the stems branch out
8
Q
Name the 3 types of tissues composing roots and shoots:
A
- dermal tissue
- ground tissue
- vascular tissue
9
Q
Dermal tissue
A
- epidermis
10
Q
Ground tissue
A
- plants
- used for storage, photosynthesis, secretion, forming fibers for support and protection
11
Q
Vascular tissue
A
conducts fluids and dissolved substances
12
Q
What is a meristem?
A
- specialized cells in the root and shoot apices and other parts of the plant
- acts like stem cells in animals
- a meristem cell divides to give rise to a differentiating daughter cell and a cell remains as a meristem cell
13
Q
Where are apical meristems located?
A
located at tips of roots and shoots
14
Q
Apical meristems
A
- involved with extension of roots and shoots
- new cells are added at tips
15
Q
Primary tissues
A
tissues derived from apical meristems; the new ones
16
Q
Primary Plant body
A
Extension of root and stem
17
Q
Root cap
A
protects delicate cells of root apical meristem; sloughed off and replaced as root grows through soil - produces slimy substance to help push through soil
18
Q
Leaf Primordia
A
shelters growing shoot apical meristems from desiccation
19
Q
Apical meristems give rise to what 3 tissue systems:
A
Protoderm, procambium, ground meristem
20
Q
Protoderm
A
forms epidermis
21
Q
Procambium
A
produces primary xylem (water transport) and primary phloem (nutrient transport)
22
Q
Ground meristem
A
differentiates into more ground tissue
23
Q
What is intercalary meristems and where would you find them?
A
found in horsetails and corns; more specifically found in the internodes and add to the length of the internodes
24
Q
What type of growth is involved with lateral meristems?
A
increases in root and shoot diameter known as secondary growth
25
Lateral meristems
form from ground tissue that is derived from apical meristems (monocots are the major exception)
26
Secondary growth
can increase girth in non-woody plants, but the effects are most striking in woody plants
27
What 2 lateral meristems are in woody plants?
cork cambium and vascular cambium
28
Cork cambium
what makes the bark; contributes to outer bark of tree
29
Vascular cambium
located just beneath bark; produces vascular tissue
30
What is secondary xylem?
main component of wood
31
What is secondary phloem?
close to outer surface of woody stem
32
What happens if secondary phloem is damaged or removed?
remove bark of tree - damage to phloem - may eventually kill tree
33
Secondary tissues
most of the trunk of a tree, branches, and older roots of trees and shrubs
34
Secondary Plant Body
all the secondary tissues
35
Dermal Tissue Examples
One cell thick in most plants
- forms outer protective covering of plant
- cuticle composed of fatty cutin to protect young, exposed parts of plants
- desert succulents may also have several layers of wax to curb water loss and help block UV radiation
- sometimes dermal tissue forms tree bark
36
Guard cells
- example of dermal tissue forming tree bark
- paired, sausage-shaped cells that flank a stoma (opening) on the leaves, stems, and fruits of plants
- contains chloroplasts, unlike other epidermal cells
- allow passage of oxygen and carbon dioxide and diffusion of water in vapor form
- many times, stomata are more numerous on underside of leaves (minimizes water loss), but water lilies are the exception
37
Trichomes
- hairlike outgrowths of epidermis
- found frequently on stems, leaves, and reproductive organs
- function in keeping leaf surfaces cool, reducing water evaporation, protecting from UV radiation and highlight intensity, serving as a buffer against temperature fluctuations
- glandular trichomes may secrete sticky or toxic substances
38
Root Hairs
- extensions of epidermal cells, but not a separate cell
| - increase surface area to maximize water and mineral uptake
39
What is ground tissue?
- all vascular and epidermal tissue
| - makes up the bulk of the plant
40
Parenchyma
- type of ground tissue
- most common type of plant cell
- function is storage of food and water, photosynthesis, and secretion
- cells may live for many years (over 100 years in some cacti)
- most of the cells in fruits such as apple are parenchyma
-
41
Chlorenchyma
- a photosynthetic parenchyma
| - found in leaves and out parts of herbaceous systems
42
Collenchym
- example is celery strings
- tough, but flexible cells support plant organs allowing them to bend without breaking
- found in stems and leaf petioles
- have living protoplasm just like parenchyma and can live for many years
43
Sclerenchyma
- cells have tough, thick walls
- mature cells don't have living protoplasm
- cells contain lignin that make cell walls more rigid
44
Two forms of Sclerenchyma
1) fibers forming long, slender strands; linen woven from sclerenchyma fibers of flax plant
2) sclereids vary in shape and are often branched; gritty texture of a pear is from groups of sclereids in soft flesh of fruit
45
Vascular Tissue
xylem, phloem
46
Xylem
principal water-conducting tissue made up of vessels and tracheids
47
How does water move through the xylem?
water moves in an unbroken stream through the xylem from roots to shoots to the leaves
48
Transpiration
diffusion of water vapor from a plant
49
Phloem
principal food-conducting tissue in vascular plants; is composed of sieve cells and sieve tube members
50
Roots adapted for..
growing underground and absorbing water and solutes
51
What are the four regions of roots?
- root cap
- zone of cell division
- zone of elongation
- zone of maturation
52
Root cap
protects the root and functions in perception of gravity; can tell up from down
53
Zone of cell division
contains apical meristem
54
Zone of elongation
extends root through soil
55
Zone of maturation
cells become differentiated
56
Modified roots
1) taproots
2) fibrous root
3) adventitious roots
57
Adventitious roots
roots that arise from the stem or some place other than the root of the plant
- can function in support, stability, acquisition of oxygen, storage of water and food, or parasitism of a host plant
58
Taproots
consist of single large root w/ smaller branching roots
59
Fibrous roots
systems are made up of many small roots of similar size
60
What are the function of stems?
they carry leaves and flowers and support the plant's weight
61
Where are the leaves attached?
they are attached to the stems at the node
62
What are the types of leaf arrangements?
alternate, opposite, and whorled
63
What is the most common leaf arrangement?
most often the leaves are arranged spirally around the stem 137.5 degrees apart - this angle relates to the golden mean.
64
Golden mean
a mathematical ratio found in nature
65
What is the significance of the 137.5 degrees apart?
May maximize the exposure of leaves to the sun
66
Arrangement of vascular bundles in Monocots
vascular bundles are scattered throughout the ground tissue of the stem
67
Arrangement of vascular bundles in Eudicots
vascular bundles are arranged in a ring around the outside of the stem - the interior of the stem is pithy
68
Secondary growth in Monocots
does not have secondary growth
69
Secondary growth in Eudicots
exhibits secondary growth as the vascular cambium produces secondary growth; this shows up as annual growth rings
70
What do modified stems do?
they carry out vegetative propagation and store nutrients
71
What are some examples of modified stems?
Bulbs, corms, rhizomes, runners and stolons, tubers, and tendrils
72
Bulbs
swollen underground stem consisting of fleshy leaves attached to small knob-like stems with adventitious roots at the base
EX. onions, lilies, and tulips
73
Corms
sort of look like bulbs, but when cut, there are no fleshy leaves - they are stems with some brown, papery nonfunctional leaves on the outside and some adventitious roots
EX. Crocus, gladiolus
74
Rhizomes
Horizontal stems that grow underground - adventitious roots grow from the lower surface
EX. ferns, bearded iris, perennial grasses
75
Runners and stolons
Horizontal stems with long internodes that grow just above the surface of the ground
EX. Strawberries
76
Tubers
tips of rhizomes swell and become tubers - the "eye" of the potato is evidence where a leaf is formed when the tuber started to grow - the eye is an axillary bud and will grow into a new potato plant
77
Tendrils
twining stems that aid in climbing
| EX. English Ivy, grapes
78
What are some modified leaves
tendrils of peas and pumpkins
79
What is the primary function of leaves?
is the primary site for photosynthesis
80
Leaves are determinate structures, what does this mean?
they stop growing at maturity
81
Leaf anatomy
most leaves have dorso-ventral symmetry resulting in more surface area for photosynthesis
82
Blade
main part of leaf
83
Petiole
stalk that attaches leaf to main stem of plant
84
Veins
vascular bundles made of xylem and phloem
85
Veins in Monocots
have parallel leaf veins
86
Veins in Eudicots
have netted or reticulate veins
87
Simple leaves
blades are not divided
88
Compound leaves
blades divided into leaflets
89
What are the three types of tissues in leaves?
a) epidermis with guard cells
b) vascular tissue
c) mesophyll (site of photosynthesis)
90
Modified leaves include:
floral leaves, spines, reproductive leaves, insectivorous leaves
91
Floral leaves
(bracts) surround the true flowers (which can be quite small) and act as showy petals
EX. poinsettia, dogwood
92
Spines
(not the same thorns or prickles) are modified leaves on cacti and some other plants - they can reduce water loss and can deter predators
93
Reproductive leaves
little plant-lets growing along margins that when separated can grow into a full-sized plant (kalanchoe)
94
insectivorous leaves
traps insects to provide supplemental nutrition - these plants often live in acid swamps that do not provide all the nutrients the plant requires
EX. sundews, Venus flytrap, pitcher plants
