Plant Biology Flashcards
1
Q
Indetermined growth
A
Growth that has no genetically pre defined limits (due to meristems, leaves/flowers)
2
Q
Tropism
A
Plants move by regulating cell expansion and turgidity (how filled with water they are)
3
Q
Plant adaptations for land
A
Waxy cuticle, stomata, vasculature, pollen, seeds, organ specialization, lignification
4
Q
When did plants move to land?
A
~490 mya
5
Q
How are algae and plants similar?
A
Both have plastids, double membranes, circular genomes, oxygenic photosynthesis, and derived from endosymbiosis
6
Q
What are the origins of plastics?
A
Cyanobacteria
7
Q
T/F: plastids evolved from a single origin
A
True
8
Q
What are the closest living relatives to land plants?
A
Fresh water charophytes
9
Q
Sporopollenin
A
Layer of polymer that protects exposed zygotes from drying out and is present in all land plants
10
Q
Why did plants evolve pigments?
A
To protect from UV and signal animals
11
Q
What was the solution to lack of structure?
A
Already had cellulose and hydrostatic skeleton but then gained rhizoids/roots and xylem/lignin
12
Q
What is the purpose of meiosis?
A
To produce a spore (single haploid cell)
13
Q
What is the purpose of mitosis?
A
Spore division (n -> many n’s)
14
Q
Draw alteration of generations cycle
A
:)
15
Q
Gametophyte
A
(n) haploid, produces haploid gametes by mitosis
16
Q
Sporophyte
A
(2n) result of gamete fusion, produces haploid spores by meiosis
17
Q
What traits are in land plants but not charophytes?
A
Alteration of generations, spores produced in sporangia, multicellular gametangia, multicellular/dependent diploid embryos, and apical meristems (except Bryophytes)
18
Q
Benefits of an aquatic environment
A
Lots of water, steady environment, easy reproduction, and no structure
19
Q
Bad parts of an aquatic environment
A
Currents control plant movement, limited minerals/light/CO2/O2
20
Q
Benefits of land environment
A
More light/CO2/O2/minerals, few competitors (at first), and land is steady
21
Q
Bad parts of land environment
A
Limited water, extreme weather, tough reproduction, UV, need structure
22
Q
What do plants need to develop to survive on land?
A
Reduce water loss, improve nutrient/water access, grow to capture light, transport water, survive weather, protection from UV, protect gametes, and protect zygote
23
Q
Alteration of generations in bryophytes
A
Sporophytes depends on gametophytes and the gametophyte is dominant
24
Q
Alteration of generations in seedless plants
A
Independent gametophyte and dominant sporophyte
25
Alteration of generations in seed plants
Sporophyte is dominant and the gametophyte is dependent
26
Draw the bryophyte life cycle
:)
27
Thallus
(Liverworts) plant body that does not differentiate into stems and leaves and lacks true roots/vascular system
28
Gemmae cups
Cup like structures that contain gemmae and contain air pores to all diffusion
29
Gemmae
Bud that can fall off and form a new plant
30
Main features of bryophytes
Waxy cuticle, stomata, no vascular/support system, no true leaves/roots, have rhizoids, flagellated sperm, spores have sporopollenin
31
Challenges bryophytes face
Sensitive to UV/mutagens, cannot compete for light, require a wet environment
32
Examples of bryophytes
Mosses, liverworts, hornworts
33
Example of a seedless plant
Ferns
34
Draw the life cycle of a seedless plant
:)
35
Sporangium
An enclosure in which spores are produced
36
Main features of seedless plants
Waxy cuticle, stomata, true roots, true stems with lignin/fiber, vascular tissue (xylem/phloem), and spores with sporopollenin
37
What features differ between bryophytes and the seedless?
Seedless have vascular system (xylem/phloem), true leaves/roots (lignin/fiber), spores
38
What challenges do seedless plants face?
Require wet environment, unprotected gametophyte, spores not suited for survival
39
Examples of seedless plants
Gymnoperms and angiosperms
40
Draw the life cycle of a seed plant
:)
41
Examples of gymnosperms
Pines, cycads, Ginko
42
Features of gymnosperms
Roots, seeds, airborne pollen, recessed stomata, tracheids in xylem, integuments (2n) to protect megaspore, NO ovary, reduced leaves (needles), zygote development in cone
43
Draw the life cycle of a gymnosperm
:)
44
Example of angiosperm
Flowering plants
45
Draw the life cycle of angiosperms
:)
46
Features that are unique to angiosperms
Ovary, exploited flowers/pollinators, created fruit, created endosperm
47
T/F: flowers have determined growth
True, the female gametophyte is in the ovule where fertilization occurs to form embryo
48
Why does reproduction in angiosperms differ from all other land plants?
Have double fertilization
FG (n) + MG (n) = zygote
FG (2n) + MG (n) = endosperm (3n)
49
Benefits of endosperms
Express unique genes involved in hormone responses, can accumulate storage compounds, and can regulate germination time
50
Microspores develop into _____
Pollen grains that contain male gametophytes
51
Pollination
Transfer of pollen to ovules
52
Benefits of seeds
~360mya
Enabled those that had them to be dominant producers, consisted of embryo/nutritious tissue/seed coat, can be dormant for years until germination favored
53
What are the two types of angiosperms?
Monocots and dicots
54
Features of monocots
(Orchids, grasses, palms) One cotyledon, are a monophyletic group, one leaf in its embryo
55
Features of dicots
Two cotyledons, not a monophyletic group
56
What features first appeared in gymnosperms?
Protection of female gametophyte in an ovule, pollen with sporopollenin, and seeds
57
What features first appeared in angiosperms?
Flowers, ovaries, fruit, double fertilization (seeds with endosperm)
58
Functions/features of roots
Indetermined growth, anchorage, attachment, water/ion absorption, symbiotic association, sugar storage, host penetration
59
Primary root
Root that is first to emerge
60
Lateral root
Branching off the primary root to improve anchorage and water absorption
61
Taproot system
Root branching derived from primary roots (gymnosperms and dicots)
62
Fibrous root system (adventitious)
Primary root dies and new roots grow from stem with the same length and thickness (monocots)
63
Root hairs
Near the root tip to increase surface area of root
64
Root cap
Protective layer of root tip meristem
65
Meristem
Groups of dividing cells
66
Prop roots
Roots that arise from stems to provide extra support (monocots and fibrous systems)
67
How do roots make their own energy?
By respiration (using up oxygen) because roots are porous
68
Symbiotic association
Interaction in which both parties involved benefit
69
Bacterial nodules in legumes
Bacteria fix nitrogen for the roots and the roots provide sugar to the bacteria (symbiotic association)
70
Mycorrhiza
Roots increase their ability of capturing water/nutrients from fungi and the fungi obtain carbs/vitamins from the root (symbiotic association)
71
Node
Point at which leaves are attached
72
Internode
Stem segments between nodes
73
Apical bud
Growing shoot tip through primary growth
74
Auxiliary bud
Has potential to form lateral branch, thorn, or flower
75
Leaf
Main photosynthetic organ that can intercept light, exchange gases, dissipate heat, and defend the plant
76
Blade
Broad, flat circumference of the leaf
77
Petiole
Stalk that joins leaf to stem node
78
Examples of modified leaves
Spines, tendrils, reproductive leaves, storage leaves
79
Veins
Vascular tissue of leaves
80
What type of veins do monocots have?
Parallel veins
81
What types of veins do dicots have?
Branching veins
82
Tissue
Collection of cell types from the same meristem
83
Features of the dermis tissue
Interphase between plant body and the environment, exchange gases, absorb water, prevent dehydration, produces cuticle, protects
84
Examples of dermis cells
Pavement cells, guard cells, root hairs, unicellular trichomes
85
Trichome
Small hair/outgrowth from the dermis
86
Pith
Ground tissue internal to the vascular tissue
87
Cortex
Ground tissue external to the vascular tissue
88
Functions of ground tissue
Storage, photosynthesis, support, and transport
89
Types of ground tissue
Parenchyma, Collenchyma, sclerenchyma, fibers, sclerids
90
Features of parenchyma
Thin cell walls
| - photosynthesis, storage, synthesis
91
Features of Collenchyma
Unevenly thickened cell walls
| - flexible support (no lignin)
92
Features of sclerenchyma
Thickened cell walls within lignin
| - rigid support, dead once mature
93
Features of fiber
Long and in bundles (cotton fibers)
94
Features of sclerids
Short, irregularly shaped (seed coats, nut shells)
| - cubic, not elongated, non flexible support
95
Features/functions of vascular system
Facilitates the transport of materials through the plant and provides mechanical support
- consists of xylem and phloem
96
Xylem
Part of vascular system that conducts water and dissolved minerals upward from the roots into the shoots, have parenchyma and fibers
- thick cell walls with lignin, die once mature
97
Phloem
Part of vascular system that transports sugars from where they are made to where they are needed, has parenchyma and fibers
- living, have plasma membrane
98
What are the three types of xylem?
Vessel elements (Angiosperms), tracheids (Gymnosperms), and fibers
99
Describe the features of vessel elements
Pipes with perforation plates and no cellular content used for water transport
100
Describe the features of tracheids
(Gymnosperms) water permeable pits for long distance transport
101
Describe the features of fibers
(Angiosperm) have no water conductive support or movement of water
102
What are the two types of phloem?
Sieve tubes and companion cells
103
Describe the features of sieve tubes
Tubes of joint cells, result in a perforation plate that allows water/solute flow, alive at maturity but NO organelles
104
Describe the features of companion cells
Alive at maturity with a nucleus, keep sieve tubes alive, assist phloem loading
105
Apical meristem
Located at tips of roots and shoots, continuous, elongation to produce leaves and auxiliary buds (primary growth)
106
Secondary/lateral meristem
Activated only when tissue and organ differentiation are complete, increases width (vascular and cork cambium)
107
Indeterminate growth
Plants ability to grow their entire lifetime involving no differentiation
108
Determinant growth
Some parts of plants stop growing at a certain size (leaves and flowers)
109
Shoot apical meristem
Generation of leaves and flowers, controls branching, generates dermal/vascular/ground tissue, controls leaf and auxiliary bud position
110
Root cap
Root tip cover that protects the root apical meristem as it grows
111
Pericycle
Outermost cell layer of the vascular cylinder
112
Where are lateral shoots developed from?
Auxiliary buds
113
What is unique about dicot stems?
Vascular tissue is in bundles
114
What are the components of leaves?
Guard cells, cuticle, veins, parenchyma, xylem/phloem, stoma, Collenchyma
115
What type of plants do not have secondary growth?
Monocots
116
Vascular cambium
Lateral meristem that adds layers of vascular tissue called secondary xylem (wood) and secondary phloem
117
Cork cambium
Lateral meristem that replaces epidermis with periderm (cork)
118
Describe tree ring formation
In spring xylem is activated and adding width, in summer the xylem begins diminishing and are replaced by fewer cells with decreased diameter
119
Osmosis
Water diffusion through semipermeable membrane from high to low concentration
120
What does positive water potential pressure mean?
Water is compressed into the cell
121
What does a negative water potential solute mean?
Solute level is rising
122
Turgid
Swollen with water
123
Flaccid
Limply full of water
124
Plasmolyzed
Shriveled (water loss due to osmosis)
125
Transpiration
Water is taken up by roots and lost to air through leaves
126
What causes water to be drawn into the roots?
Tension (negative pressure)
127
Cohesion
Water molecules stick to one another through hydrogen bonding to form a strong column
128
Adhesion
Water molecules stick to the walls of the xylem to make it impermeable
129
Tension cohesion theory
Negative pressure (tension) is generated inside the xylem transport elements (vessel and tracheids)
130
Trend of xylem sap speed and plant type
Conifers with tracheids have a very low speed and vines with vessel elements have a very fast speed
131
Tracheids translocation
Water is forced to go through small pits with high resistance
132
Vessel element translocation
Water flows through perforation plates with lower resistance and better efficiency
133
Cavitation
Bubble formation in the xylem transport elements
134
Embolism
Space between water above and below cavitation point (the bubble)
135
What factors cause cavitation?
High tension inside transport elements due to high transpiration rate, water freezing inside, fungal infection
136
Cavitation and tracheids vs vessel elements
Tracheids are better suited for embolisms because the embolism cannot spread, vessel elements can spread to other vessels until empty
137
Guard cell
Epidermal cell that can cause the stoma pore to open or close and take in or release O2, CO2, H2O
138
Conditions when the stoma is open
Turgidity, light, high potassium, low CO2, low ABA, water moving in
139
Conditions when stoma is closed
Flaccid, darkness, low potassium, high CO2, high ABA, water moves outward
140
Abscisic acid (ABA)
Potassium ion regulator that is controlled by turgor pressure
- drought hormone: dry= low water and potassium= high ABA
141
Apoplastic route
Pathway outside the plasma membrane through the non living parts of the cell with no filtering
142
Symplastic route
Pathway that goes through plasma membrane via channels and filtering (plasmodesmata)
143
Endodermis and plastic routes
Forces both routes to become symplastic in order to filter with Casparian strips
144
Phloem sap
Sugar solution that travels from sugar source to sugar sink
145
Sugar source
An organ that is the net producer of sugar such as mature leaves
146
Sugar sink
An organ that is a net consumer/stored of sugar such as a tuner or bulb
147
Describe the path of sucrose movement from source to sink
See quiz :)
148
What are the two ways phloem loads sucrose?
Passive (symplastic with diffusion) or active (apoplastic with ATP)
149
Order of highest to lowest water potential of a tree
Soil> root> trunk> leaf> air
150
In what forms do plants get nitrogen from soil?
Nitrate and ammonium
151
Describe NPK
Nitrogen-phosphorus-potassium, farmers alter these ratios in fertilizers based on plant type
152
Rhizosphere
Nutrient rich region of soil with plant root region directly influenced by chemical and symbiotic associations
153
Where does nitrogen fixation occur?
Root nodules
154
How does a root nodule develop?
Chemical attraction to root, thread of infection, growth, and development of vascular connections
155
Describe the Rhizobium-plant association
Plants get fixed nitrogen from Rhizobium and the bacteria get sugar and an anaerobic environment from the plant (ex: legumes) to develop a nitrogen fixing root nodule
156
Mycorrhizae
Association between fungi and roots— fungi get sugar, plants get secreted growth factors
157
Pros and cons of sexual reproduction
Formation of fruit, maintains genetic diversity, expensive, but better for survival and reproductive success
158
Pros and cons of asexual reproduction
(Rhizomes/tubers) fast and cheap, reduces genetic diversity, makes plants susceptible to immune attack
159
What is a flower?
A modified shoot that attracts pollen with its make and female organs that developed from a switch in the apical meristem
160
What makes up the stamen?
Anther and filament
161
What makes up the carpel?
Stigma, style, ovary
162
Which parts of a flower undergo meiosis?
Anther (microspore) and ovule (megaspore)
163
Complete flower
Contains all four plant organs: stamen, carpal, petal, sepal
164
Incomplete flower
Missing one or more of the main plant organs
165
Inflorescences
Clusters of flowers (ex: dandelion)
166
Coevolution
Joint of evolution of interacting species in response to selection caused by one another (flowering plants and pollinators)
167
How does pollination occur?
Pollen grain moves from anther to stigma via wind, water, or animals
168
What strategies attract pollinators?
Nectar, alternating exposure of anther/stigma, decorated flowers developing features that favor only one type of animal
169
What is unique to the angiosperm life cycle?
Double fertilization
170
Draw the angiosperm life cycle
:)
171
Draw the development of the microspore
:)
172
Draw the development of the megaspore
:)
173
Draw a diagram of the embryo sac
:)
174
Draw a mature male gametophyte
:)
175
Why use double fertilization?
Ensures plants will not commit resources to produce energy rich endosperm until after the egg is fertilized
176
What are the three steps in seed development?
Zygote —mitosis—> embryo
Endosperm mother -nourishes-> endosperm
Ovule integuments —-> seed coat
177
Steps of endosperm development
Triploid cell that results from multiple mitotic divisions without cytokinesis, expands, absorbs nucellus, becomes energy rich, and is consumed by developing seed
178
What is the fate of the endosperm in monocots vs dicots?
Dicots: endosperm is partially or completely consumed
Monocots: does not consume endosperm
179
Characteristics of fruit
Ovary wall after fertilization, protects enclosed seeds
180
Benefits of seeds
Ensure plant survival, can remain dormant until in proper conditions
