Exam 3 Flashcards
apical dominance
suppression of growth of lateral or axillary buds perhaps by auxin-like inhibitor
serescence
breakdown of cell components (in deciduous plants and conifers) influenced by ABA and ethylene
twining movement
occurs in stems when cells elongate to different extent
-tendril twining stimulated by contact
nastic movements
-non directional movements that don’t result in an organ being oriented toward or away from direction of stimuli
tropisms
permanent movements resulting from stimuli coming from one direction (positive or negative)
phototropism
-tulip exposed to light from 1 direction over several weeks
-auxin influences this
gravitropism
-response to gravity
-roots positively gravitropic, negatively phototrophic
statolith
-starch containing plastid that act as gravity sensor
-common in roots
-amycoplasts have possible role in gravitropism
clinostat
device to counter effects of gravity in plant
thigmotropism
-a response by plant or plant part to contact with a solid object (coiling or twining)
-coiling results from cells in contact becoming slightly shorter and those on opposite side elongate
chemotropism
-response to presence of chemical
turgor movements in plants
-result from changes in internal water pressures
-ex. barberry flower: stamens jerk inwards when in contact with pollinator to encourage pollen deposition
sleep movements
-circadian rhythm in plants
-turgor movements are involved along with external stimuli of light and temp
-turgor changes caused by movement of water into and out of cells at bases of leaves and leaflets
photoperiodism
-length of day is related to onset of flowering in many plants
critical daylight
12-14 hours for initiation of flowering
short day plants
-ex. poinsettia
-flower if day length is shorter than critical length
long day plants
-ex. spinach, wheat, potatoes
-flower if periods of light are longer than critical length
day neutral plants
-can flower anytime of year
phytochromes
-pigments that control photoperiodism
-p red or pr absorb red light
-p far red and per absorb far red light
-one form is changed to other when exposed to right wavelength of light
thermoperiodism
-predict date of harvest based on temp and growth rates
degree days
measure number of days that temp exceed a certain level and will cause plant to flower
dormancy
-period of growth inactivity in seeds, buds, bulbs, and other plant organs even when temp, water, or day length would typically cause plant growth
theophrastus
-classified 500 plants as trees, shrubs, and herbs
-leaf characteristics
carolus linnaeus
-binomial nomenclature
-father of modern taxonomy
-developed a system of classifying plants (based on number of stamens)
artificial system of classification
based on similarity of appearance but not relationships
natural system of classification
-darwin
-based on relatedness
-closely related plants are placed into one group
-systematics
international code of botanical nomenclature
-icbn
-rules for naming and classifying plants
-two rules: latin description published, type specimen established
taxa
nested within larger categories of taxa
type specimen
specimen upon which a new species is based
-specimens housed in museum, university, plant collection
international code of nomenclature for cultivated plants
-icncp
-cultivars (cultivated variety)
species name adjective
-place, people, trait of plant
-can’t be changed even if wrong
kingdoms
-started with just plants and animals
-1960s: protista, fungi, plants, animals, bacteria
-1990s: archaea, eukarya, bacteria
-today there are 3 domains
kingdom protista
-no longer recognized as a unified kingdom
-current systematists consider group once called protista to consist of multiple evolutionary lines of organisms (supergroups)
major taxonomic groups
domain, kingdom, phylum, class, order, family, genus, species
-did king Philip come over for good soup
morphological species concept
based on morphology or appearances
-useful for examination of herbarium species
interbreeding (biological) species concept
-species is a population capable of interbreeding and is reproductively isolated from other such groups
-timing, genetic incompatibility, geographic isolation
ecological species concept
-a group of related individuals that occupy a unique ecological niche
phylogenetic species concept
-grouping of organisms with shared evolutionary past
-phylogenetic trees
phylogeny
history of evolution of species or group, especially in reference to lines of descent and relationships among blood groups of organisms
phylogenetics
-study of evolutionary similarities among groups of organisms
cladistics
analysis of shared features to determine natural relationships among organisms
clade
a group consisting of an ancestor and all its descendants, a single branch on the tree of life
cladogram
straight line diagram used to portray evolutionary relationships
phylocode
-a new classification system based on phylogenetic relationships and clades
-many relationships now determined by molecular analysis
-evidence that currently recognized taxonomic groups may consist of unrelated organisms
bacteria
-small and abundant
-most bacteria and harmless and can be beneficial
-some species are motile with simple flagella
-reproduction is primarily asexual through fission
heterotroph nutrition in bacteria
primarily absorption through cell wall
autotroph nutrition in bacteria
-chemosynthesize (energy to build carbs is derived from bonds in inorganic molecules)
-photosynthesize
conjugation
dna transferred from donor cell to recipient cell usually through pilus
transformation
-living cells acquire dna fragments released by dead cells
-griffith and Avery
-virulent was heated and killed
-avirulent was living and heat killed virulent
transduction
dna fragments carried from one cell to another by viruses
phylum bacteriophyta
-bacteria differ from archaea in rna bases, metabolism, and lipids
-many are heterotrophic (or saprobes: obtain energy from decaying organic matter)
unpigmented purple and green sulfur bacteria
-autotrophic: can synthesize organic compounds from simple inorganic substances
-use pigments and chemical pathways that differ form those used in cyanobacteria and plants
-purple have bacteriochlorophyll: greenish pigments similar to chlorophyll a in plants
human relevance of bacteria
-organic waste and leaves (compost)
-diseases and illnesses caused by bacteria
-biological control (like in pest control)
bioremediation
-use of living organisms in the clean up of toxic wastes and pollution
-ex: breakdown oil in oil spills
class cyanobacteria (green blue bacteria)
-have chlorophyll a, can produce o2
-have pigments called phytocobillins (have role in ps)
-phycoerythrin (red) and phycocyanin (blue green), can have carotenoids
-can fix nitrogen
-can be found in diverse fresh and marine habitats
cyanobacteria survival
-can be first colonists on bare lava
-can survive in fissures in desert rocks
heterocysts
play role in nitrogen fixation
akinetes
play role in resisting freezing and other adverse conditions
algal blooms
-some species held together by gelatinous sheaths
-some form cyanophycin (nitrogenous food reserve) and also store carbs and lipids
class prochlorobacteriae
-prochloron possesses chlorophyll a and b and no phycobillins
-carotenoids
-adds support to idea that chloroplasts arose as bacterial cells living within other cells
salt bacteria
-live in harsh environments
-carry out simple photosynthesis using bacterial rhodopsin
viruses
-core of rna or dna surrounded by a protein coat
-replicate at expense of host cell
asexual reproduction
vegetative reroduction
sexual reproduction
meiosis in male and female associated structures
sporocytes
diploid cells that undergo meiosis
haploid
-gametophyte (gametes)
-one set of chromosomes
diploid
-sporophyte (zygote)
-two sets of chromosomes
polyploid
-more than 2 sets of chromosomes
-ex. triploid: navel oranges
-tetraploid (4n)
coleochaete
-green alga presumed to be an indirect ancestor to land plants
-cells that resemble parenchyma
-form cell plate during mitosis
-form zygote protective covering
-produce lignin like compound
protist characteristics
can be made up of single cell, multicellular, colonies, or filaments
-autotrophs or heterotrophs
-some motile (multicellular are stationary)
phylum chlorophyta
-green algae
-diverse forms and habitats
-most common mutualistic alga in lichens
-chlorophylls a and b
-store energy in starch
plankton
-organisms suspended in water column
-phytoplankton are base of food chain
volvox
colonial: all cells similar in function in organisms
-chlorophyta
ulothrix
-chlorophyta
-multicellular: specialization is cell function
-filament: long chain of cells
chlamydomanas
-contractile vacuole: pumps water out
-pyrenoid: synthesis of starch
-cup shaped chloroplast
-eyespot: promotes movement towards light
isogamy
sexual reproduction when both gametes are the same size
spirogyra
-filamentous alga
-reproduce asexually by fragmentation of filament
-have spiral chloroplast
-haploid, isogamy
sexual reproduction in spirogyra via conjugation
-conjugation tube provided pathway for gamete to move from one cell to another and fuse with stationary gamete
oedogonium
-oogamy
-multicellular
-oogonium and antheridium
-zygotes can remain dormant for up to a year and undergo meiosis
oogonium
specialized cell in filament that holds egg
antheridium
specialized cell in filament that releases sperm cells
asexual reproduction in oedogonium
vegetative cells release zoospores, settles, forms holdfast which forms filament through mitosis
hydrodictyon
-water net
-asexual reproduction by daughter colonies, sexual repro by isogamy
acetabularia
-mermaids wine glass
-one very large cell
ulva
-sea lettuce
-blades may be haploid or diploid
phylum chromophyta
-about 7600 species
-food reserves
-specialized pigments
-coenocytic: mitosis without cytokinesis
xanthopyceae
-yellow green algae
-fucoxanthin except in vaucheria
vaucheria
-oogamous
-coenocytic
-filamentous
chrysophyceae
-golden brown algae
-statospores: formed by many species
-silicified wall
bacillariophyceae
-diatoms
-chlorophyll a, c1, c2, and fucoxanthin
-silica shell in an organic framework of pectin and other substances
-food reserves (oils, fats, or laminarin)
reproduction in diatoms
-division
-asexually: with every division one new cell the size of parent and one is smaller than parent cell
phaeophyceae
-brown algae
-kelp
-algin in or on cell wall
-pigments (fucoxanthin , chlorophyll a and c)
-have gas bladders that help algae float upright
nereocystis
-brown alga
-multicellular
-laminarin (main food reserve)
-algin
-gas bladder, blades
brown algae life cycle
separate male and female thalli
gametangia
structures where gametes are produced in conceptacles
rhodophyta
-red algae
-phycobilins, chlorophyll a and d
-red to purplish color due to phycobilins (similar ini cyanobacteria)
-store energy in Floridean starch
-produces agar
phylum dinophyta
-dinoflagellates
-around 40 species
-responsible for red tides
-have 2 flagella
phylum cryptophyta
-have pyrenoids and chloroplast
diatomaceous earth uses
-filtering liquids, reflectorized paints, swimming pools, metal polishes, toothpaste, gardeners
kelp uses
-algin used in making ice cream, salad dressings, beer, jelly beans
-iodine, nitrogen, and potassium
-seaweeds used in foods
plants
term used for bryophytes, ferns, cone bearing and flowering plants, and relatives of those plants
-multicellular, photosynthetic
-chlorophyll a and b, carotenoids
-starch
-phragmoplasts and cell plates
-cell walls made of cellulose
land plants
-cuticle on plant surface
-gametangia and sporangia become multicellular and surrounded by cells
-plant zygotes developed into multicellular embryos
-plants are more complex than cyanobacteria and algae
bryophytes
-non vascular
-need water to reproduce
-often found in moist and shaded areas
-can be found in very large range of heights
-can live in very specific conditions
lenslike cells
found in luminous moss and glow an eerie golden-green reflected light
protonema
-immature gametophyte consisting of a short filament of cells
-originates from spores
phylum hepaticophyta
-liverworts
-around 8000 species
-thalloid: flattened, lobed, somewhat leaf like body
-some resemble mosses
male gametophore
antheridophore
female gametophore
archergoniophore
thallus
-multicellular plant body that is flattened
-not differentiated into leaves, stems, roots
-pores for gas exchange
-chlorenchyma cells for photosynthesis
-rhizoids: structures that help anchor
sexual phase of liverworts
-sperm swims to archegonium and fertilizes egg
-sporophyte is attached to egg
-foot-seta-capsule-meiosis-spores
asexual phase of liverworts
-gemmae cups: inside are fragments of tissue called gamma that can splash out and develop new plant
elater
-bands of tissue interspersed within sporophytes
-spreads out dispersal
phylum anthocerophyta
-hornworts
-distant relatives of liverworts and mosses
-have stomates
-cells have pyrenoids similar to those in green algae
-rhizoids anchor plant
phylum Bryophyta
-mosses
-no leaves, vascular tissue, stomates, or mesophyll
-“leaves are transparent cells that absorb and store water
-rhizoids anchor plant
-water rises up plant by capillarity
mosses reproduction
-some have male and female on same plant, others on separate plants
-gametophyte is dominant life cycle
-antheridium is full of haploid sperm
sporangium
-capsule with sporophytes which undergo meiosis to become haploid spores
human uses of bryophytes
-peat moss
-antibiotic capabilities
-can be eaten (think ice man)
ferns and their relatives
-vascular tissue and true leaves developed
-roots that fcn in absorption and anchoring
-were seedless
psilotophyta
-whisk ferns
-stems only (dichotomous branching)
-not true roots or leaves
-rhizoids act as root hairs that absorb
-enations: photosynthetic flaps of tissue
phylum lycophyta
-ground pines and club mosses
-lycopodium and selaginella
-microphylls: small leaves with single vein
-true stems and roots
homospory
-lycopodium
-all spores are the same size and give rise to gametophyte with both antheridium and archegonia
lycophyta reproduction
-sporophylls: sporangium bearing leaves
-strobil: sporophylls in terminal conelike clusters
-spores produced by sporocytes
heterospory
-selaginella
-megasporium to megaspores
-microsporagium to microspores
ancestors of club mosses
-325 million years ago
-large, tree like
-dominant in carboniferous period
-contributed to vast coal deposits in this period
uses of lycopodium spores
-flash photography
-pharmacy: keep pills from sticking together
phylum equisetophyta
-horsetails
-silica
-underground rhizomes
-sporophyte dominant
-sporangiospores to spores with elaters
elaters in ferns
-adapted to spread in dry conditions and wrap up in moist conditions
phylum polypodiophyta
-ferns
-have fiddleheads
-megaphylls: large leaves with multiple veins
-sori: reproductive structures on back of leaves
indusium
flap of tissue over sporangia
petrified wood
-wood covered in water, and minerals replaces materials within wood
-insects can be found intact in the wood
