Exam 2 Flashcards
Growth of a plant
Increase in cell size by cell division and enlargement
Development of a plant
Cells differentate into organs or tissues like leaves or flowers
Development vs. Growth
Development is the actually process of gaining specialized tissue
Growth is cells growing
Where does differentation occur in plants
-The meristimatic zone
*Things like phloem and xylem will be here
Growth Promotor Hormones in plants
-Auxin
-Cytokinins
-Gibberelins
Growth inhibitors hormones in plants.
-ABA
-Ethylene
Auxin effects
-Cell elongation
-Apical Dominance
-Phototropism/Gavitropism
Auxin Cell Elongation process
Area with more Auxin develops faster and elongates more
Light breaks down Auxin, determins which side will grow faster
Auxin’s role in Apical Dominance
Apical tip (top bud of plant) suppresses lateral growth
Removal of this tip allows for lateral growth
Auxin is most present in the tips of plants
Auxin’s role in gavitropism
The effects of gravity pull the Auxin molecules to the lower root surface
The weight of the Auxin pulls the root tip down toward the center of gravity
Auxin commercial use in fruit production
Causes parthenocarpic fruit: Fruit that has no seeds
Gibberelins effects
-Stem elongation
-Bolting and flowering*
-Increase quality, size, color of fruit
*Can alter when flowering plants do this
Cytokinins effects
-Stimulate cell division
-Cell and organ enlargement
-Delays death in fruit and leaves
Cytokinins vs Auxin
Cytokinins encourage the growth of lateral buds
Auxins encourage the growth of roots
Ethylene effects
-Abscission*
-Fruit ripening
*Works with Auxin, auxin fades as the growing season ends and ethylene ^
ABA effects
-Dormancy
-Bud formation
-Stomata closure
Alteration of generations
Name the two types, what they produce, and diploid/haploid
Perfect vs. Imperfect flower
Perfect flower: Has both male and female reproductive parts (hermaphroditic)
Imperfect flower: Anytime that the flower does NOT have both reproductive part.
Monoecious plants
“one house”
Has the male and female flowers on the same plant
dioecious plants
“two houses”
Has the male flower on one plant and the female flower on a completely seperate plant.
A complete flower is…
A flower with all four whorls
The four whorls of a flower are…
-Sepal
-Petal
-Carpal (pistil)
-Stamen
Masting years are…
What years trees decide to release their seeds
Types of fruits
Dry
-Dehiscent
-Indehiscent
Fleshy Fruit
Dispersal Syndrome
Set of traits that aide in the dispersal of seeds through a specific agent
-Wind
-Water
-humans
External Dormancy in seedlings
Related to seed coat
-Seed coat must be altered physically to germinate
Two unique tissues of secondary growth
Vascular Cambium
Cork Cambium
Vascular Cambium
The producer of xylem and phloem in secondary growth
Splits the growth of the phloem and the xylem
If the vascular cambium splits the phloem and xylem, how does the two tissue age.
Youngest from the middle, then out
-Xylem:Inside
-Phloem:Toward outside
Cork Cambium function
Creates the bark, replaces epidermis
-Cork-thin, wax covered cells
Dormancy
Period of growth cessation and the formation of a resting bud, typically enclosed in scales
Quiescence
Resting state in response to environmental conditions
Three Stages of Dormancy
-Pre-dormancy
-True-Dormancy
-Post-dormancy
Dormancy Triggers
-Day Length
Actually night length
Reliable
Main signal
-Temprature
Leads to dormancy
Potentially trick trees
-Water/Minerals
Release from Dormancy
-Period of chilling (time varies)
Genotype vs. phenotype
Genotype:actual genetic code
Phenotype: Physical expression of genes and environmental factors
Types of Variation
-Mutation
-Selection
-Migration
-Genetic drift
-Non-random mating
Ecocline
-Location affecting variation
Variation affecting a population caused by adaptation to an environmental condition that varies along a gradient
Ecotypes
Family differences in traits unrelated to a gradient
Due to local environmental conditions
Two types of speciation seperation
-Habitat: delianted due to environmental differences
-Temporal: Delinated by diferences in reproductive viability
Name of the area the distingushies roots and and shoots
Hypocotyl
-Also the area where the bend is after emerging from seed coat
Radicle
The first root
The shoot system
(aka leaves and stems)
Epicotyl
Cotyledon
Protective layer under the seed coat, protects the first leaves
Rhizosphere
*Microbiome
Soil and microorganisms around the root that directly influenced by root secretions
Also the root microbiome
Colony of microorganisms that are above ground usually on the leaves of the plant
Phyllosphere
Two types of Mycorrhizae
-Endomycorrhizae
-Ectomycorrhizae
Nodulation
N-fixing bacteria infect the plant root, create nodules on the root
Two parasite types
-Holoparasite:Obligate, completly dependent on host
-Hemiparasites: Obligate or fuclative
*Holoparasites are usually devoid of green coloration
Biotrophs and Necrotrophs
Biotrophs: Rusts and mildews, little host response
Necrotrophs:wound invasion, kill cells (necro)
Quantitiative Defenses
-Hard to digest
-Carbon Rich
-Nutrient poor soils
Qualitative Defenses
-Toxic in small quantities
-Nitrogen rich
-Nutrient rich soils
