Lecture exam 3 Flashcards
chapters 11, 12, 16, 17, 18
___________ is defined as an irreversible increase in mass due to the division and enlargement of cells.
growth
Internal environmental factors coordinating plant growth and development include ________.
hormones
Which of the following groups of plants tends to be the least sensitive to auxins?
monocots
Which of the following pertaining to auxins is true?
Their migration from the cells where they originate is relatively slow.
Their movement is polar.
Their movement requires the expenditure of energy stored in ATP molecules.
They tend to proceed through parenchyma cells surrounding vascular bundles.
All of these answers are correct.
all of these answers are correct
Auxins promote the growth of the stem by
by promoting cell elogation
The most important effect of cytokinin is its influence on
cell division
Which plant hormone was isolated from a fungus causing “foolish-seedling disease”?
gibberellin
Absicsic acid is associated with maintaining ___________ in buds and seeds.
dormancy
The suppression of the growth of axillary or lateral buds is called
apical dominance
The fruit ripening process releases large quantities of
ethylene
Plant movements that are NOT oriented relative to the direction of the stimulus are called
nastic movements
Which of the following play a major role in water-conservation movements of grasses?
bulliform cells
Which of the following statements is a CORRECT comparison between photosynthesis and respiration?
Photosynthesis is an energy storing process whereas respiration is an energy releasing process.
Oxidative phosphorylation takes place when protons flow across the inner membrane of a mitochondrion. This is called
chemiosmosis
Oxidation is the
loss of electrons
Photosynthesis is an example of a/an _____________ set of chemical reactions in plants.
anabolic
The oxygen liberated by green plants during photosynthesis comes from
water molecules
Several antenna pigments function in photosynthesis. Which is found in flowering (higher) plants?
both [carotenoids and chlorophyll b] are correct
The longest wavelengths of light useful in photosynthesis are those of
red light
Which list gives the products of the light reactions of photosynthesis?
NADPH, ATP, and oxygen molecule
In the process of photosynthesis, which molecule becomes reduced?
CO2
In glycolysis
glucose is broken down into simpler compounds.
The citric acid cycle takes place in the ___________________.
mitochondria
In aerobic respiration, how many ATPs are produced from complete respiration of one molecule of glucose?
36
The first person(s) of note to attempt to organize and classify plants was/were
Theophrastus.
In the thirteenth century A.D., features of stem structure were used to recognize the following two groups: ___________________.
monocots and dicots
Linnaeus’ classes were based primarily on
stamens
Linnaeus’ classification system is now considered to be _________________, as it was not based on evolutionary relationships.
artificial
Scientific names consist of two parts and the method of naming is known as ______________.
binomial system of nomenclature
In Whittaker’s five-kingdom classification, which of the following is NOT used as a basis for distinguishing among kingdoms?
size of organisms
The kingdom-level classification system is now preceded by the ___________ category, which is based on evolutionary and biochemical characteristics of all living organisms.
domain
Which of the following species concepts is not very useful in defining plant species because some plant groups readily hybridize with other plant groups?
Interbreeding species concept.
Scientists who specialize in identifying, naming and classifying organisms are called _______.
taxonomists
Which of the following features is found only in bacteria?
lack of membrane bound compartments within the protoplast
Some genetic recombination in bacteria occurs as a result of fragments of DNA being carried from one cell to another by viruses. This process is called
transduction.
The bacterial structure formed by a single, very condensed, circular DNA molecule is called a
a nucleoid.
Which of the following possessed by eukaryotic cells is/are NOT found in prokaryotic cells?
mitochondria
Bacteria that are more or less spherical in shape are generally called
cocci
True bacteria may get their nutrition from __________________.
nonliving organic matter (saprobes)
other living organisms (parasites)
from sunlight (autotrophs)
from inorganic chemicals (chemoautotrophs)
All these modes of nutrition are used by some eubacteria species.
All these modes of nutrition are used by some eubacteria species.
Photosynthetic, algal-like bacteria are
cyanobacteria.
Which of the following is NOT a part of sexual reproduction?
vegetative spores
Which of the following statements about mitosis is NOT true?
Mitosis can only lead to growth and development of the individual.
Two chromosomes that are morphologically similar, but potentially carry different versions of each gene are referred to as ______________.
homologues
In which phase of meiosis does crossing-over occur?
prophase I
In meiosis
the process allows for a contribution of genes from both parents.
Which of the following statements pertaining to sexual reproduction is true?
The first cell of a gametophyte generation is normally a spore.
Which of the following pairs of cells do NOT have identical chromosome numbers in a given species of plant?
spore and zygote
Diploid organisms have how many sets of chromosomes?
2
The Kingdom Protista is characterized as having ______________________, making it the most diverse of the eukaryotic kingdoms.
plant-like algae
animal-like zooplankton
fungal-like slime molds
oomycetes
all of the above are found in the Kingdom Protista
all of the above are found in the Kingdom Protista
Single-celled algae found in fresh or marine waters are
phytoplankton.
Algae are placed into phyla based on their
[pigment forms, cell wall composition, and stored carbohydrates] are correct.
Which of the following reproduces asexually primarily by fragmentation?
Spirogyra
Proteinaceous structures located on algal chloroplasts and thought to contain enzymes associated with the synthesis of starch are
pyrenoids.
In a green alga such as Chlamydomonas, which of the following would you NOT expect to find?
chlorophyll d
Stoneworts and Oedogonium are both
oogamous.
The brownish pigment found in both brown algae and diatoms is
fucoxanthin.
Diatom zygotes that are capable of rapidly increasing in size are
auxospores.
The cells of which of the following are diploid?
diatom cells
No unicellular or colonial representatives of the _______________ algae have been found to date.
brown algae
Brown algae, diatoms, and yellow green algae are all classified in the phylum _________ based on shared features such as pigments, storage materials and reproductive characters.
Chromophyta
The pigments that give red algae their characteristic colors are
phycobilins.
Which statement about the toxin associated with the red tide is INCORRECT?
The toxin and the red tide are produced by a sudden and rapid increase in dinoflagellates.
The fishing industry is adversely affected by the red tide and the toxin because it kills fish, clams, and contaminates shellfish used for human consumption.
The frequency of the red tide and its geographic range has widened since the 1970s.
The same toxin is produced by blooms of the blue-green bacteria and is responsible for the fishy-smell of oceans.
The toxin may move up the food chain, killing or sicken any organism that eats the dinoflagellates or the contaminated shellfish.
The same toxin is produced by blooms of the blue-green bacteria and is responsible for the fishy-smell of oceans.
This substance which is extracted from brown algae, is used as a stabilizer for ice cream and chocolate milk, and as an emulsifier in paints and cosmetics.
algin
what is development?
the coordination of growth and differentiation of a singe cell into multicellular tissues and organs
what is differentiation?
as cells enlarge, cells develop
different forms adapted to specific functions,
e.g., transport, support
what factors influence development?
genes, internal signals and external environmental conditions
what are nutrients used for
furnish elements and energy for plant growth and maintenance
what do vitamins do?
play an important role in reactions catalyzed by enzymes
what are vitamins?
vitamins are coenzymes or [arts of coenzymes that join with a protein to form a functional enzyme–needed in small quantities– most are made by plants
what are hormones
organic substances that influence many developmental processes
how do hormones act?
by binding to specific receptor molecules
once bound they trigger a series of biochemical reactions (called signal transduction)
what are the 5 main types of plant hormones?
auxins
giberellins
cytokinins
abscisic acid
ethyene
what is a coleoptile?
a sheath covering the shoot tip and embryonic leaves of monocots
what did Went do with oat coleoptiles?
coleoptile tip onto agar and agar onto decapitated coleoptile
what did Went discover
Auxin
the substance that influenced the bending of the coleoptile
what are the 3 hormones known to promote growth?
auxins
giberellins
cytokinins
(can become inhibitory at certain concentrations)
where are auxins made?
made in apical meristems, buds, young leaves, and other actively growing parts of plant
what may auxin do at a particular concentration?
promote shoot growth and inhibit root growth
what does auxin do at appropriate concentrations?
auxins stimulate enlargement of cells by increasing plasticity of cell walls
what are oter effects of auxin?
trigger production of other hormones
cause dictyosomes to increase secretion rate
influence respiration, growth, stem growth, root initiation and more
describe the movement of auxins
polar (away from source)
and require ATP (active transport)
what is IAA used in horticulture to promote?
rooting of cuttings
flowering and fruit set
fruit retention
weed control
what do giberellins affect?
flowering (some plants)
stem length (dicots, some monocots, not conifers)
bud and seed dormancy
how do giberellins move?
through xylem and phloem, not polar like auxin
what are cytokinins?
hormones that stimulate cell division (promotes progression from the G2 phase to the mitosis phase in presence of auxin)
role in enlarging of cells, delay of aging in leaves
synthesized in root tips and germinating seeds
what does abscisic acid (ABA) do?
growth-inhibiting hormone
synthesized in plastids, probably from carotenoids
inhibits growth promoting effects of other growth-promoting hormones
once thought to play a role in promoting abscision of fruits and leaves
ABA influences transport or retention of K+ in guard cells when leaves wilted
prevents seeds in fruits from germinating
what role does ethylene play?
ripening of fruits can be accelerated by presence of ethylene (commercial uses to ripen green fruits)
ethylene production increases if fruits are bruised
pea seedling growing through soil produce ethylene if counter interference– tighter crook in stem
abscission of leaves promoted by presence ethylene
where is ethylene produced naturally?
by fruits, flowers, seeds, leaves and even roots
what is apical dominance?
the suppression of growth of latera or axillary buds perhaps by auxin-like inhibitor
what is senescence?
breakdown of cell components in deciduous plants and conifers influenced by ABA and ethylene
where are twining movements found?
the tendrils of manroot plants
occurs when cells elongate to different extent (internal factors) tendril twining is stimulated by contact
where do contractile movements occur?
found in contractile roots in bulbs
what are nastic movements?
non-directional movements that do not result in an organ being oriented toward or away from the direction of a stimulus
what are tropisms?
permanent movements resulting from stimuli coming from one direction (positive and negative)
what is phototropism?
tulip exposed to light from one direction over several weeks, auxin influences phototropism
what is gravitropism?
coleus placed on its side (stems negatively gravitropic)
what is a statolith?
starch containing plastid that acts as a gravity sensor, common in roots
what is a clinostat?
a device to counter the effects pf gravity in a plant
what is thigmotropism?
a response by a plant or plant part to contact with a solid object, e.g. coiling of tendrils, twining of climbing plant stems
why causes coiling
cells in contact becoming slightly shorter and those on opposite side elongate
what is chemotropism?
response to the presence of a chemical e.g pollen tube grows as a long tube that follows a diffusion gradient of a chemical found within a flower
what is photoperiodism?
length of day is related to onset of flowering in many plants
what is the critical daylength for photoperiodism?
about 12 to 14 hours for the initiation of flowering
what are short day plants?
plants that will only flower if the day length is shorter than the critical length (fall/spring–shorter days, longer nights)
what are long day plants?
plants that will not flower unless periods of light are longer than the critical length (summer– longer days, shorter nights)
what are day neutral plants?
plants that flower no matter the day length
what are phytochromes?
pigments that control photoperiodism
what do phytochromes influence?
photoperiodism
changes in plastids
plant development
anthocyanin production
detection of shading
seed germination
what are phytochromes?
pale blue proteinaceous pigments produced in minute amounts in meristems
what are the forms of phytochrome?
P red absorbs red light
P far red (active form) absorbs far red light
how do phytochromes interconvert?
one form is changed to the other when exposed to the right wavelength of light
what is thermoperiodism?
predicting the date of harvest based on temperature and growth rate
what is dormancy
a period of growth inactivity in seeds, buds, bulbs, and other plant organs even when temperature, water, or day length would typically cause plant growth
who first classified 500 plants as trees, shrubs, and herbs and based on leaf characteristics
Theophrastus
what century were monocots vs dicots differentiated based on stems
what century were fruit and flower structure also used to classify plants
13th
18th
what were the original latin names for plants
polynomials
who was carolus Linnaeus
father of modern taxonomy and the system of binomial nomenclature
what is an artificial system?
naming of pants based on similarity of appearance but not relationships
what is the natural system of classification
based on relatedness, closely related plants are placed into one group (systematics)
what rules did the international code of botanical nomenclature set for naming
Latin description published, type specimen established, nestled within larger category of taxa
what are the 3 domains?
bacteria archaea eukarya
list the major taxonomic groups
domain
kingdom
phylum
class
order
family
genus
species
what is the morphological species concept?
based on morphology (useful for examination of herbarium specimens)
what is the interbreeding species concept?
species is a population capable of interbreeding and is reproductively isolated from other such groups
what is the phylogenetic species concept?
the grouping of organisms with a shared evolutionary past
what is phylogeny?
the history of the evolution of a species or group, especially in references to lines of descent and relationships among broad groups of organisms
what is phylogenetics?
the study of evolutionary similarities among groups of organisms
what is cladistics?
analysis of shared features to determine natural relationships among organisms
what is a clade?
a group consisting of an ancestor and all its descendants, a single “branch” on the “tree of life”
what is a cladogram?
straight line diagram used to portray evolutionary relationships
what is 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 species. they are not natural
what is the nutrition of bacteria and archaea?
primarily absorption through cell wall (heterotroph)
some chemosynthesize
some photosynthesize (cyanobacteria and choroxybacteria)
describe bacteria
abundant, small (0.2-10u)
90% are harmless or beneficial
some species motile
reproduction primarily asexual
what are the steps to binary fission in bacteria?
DNA replicates
cell elongates
septum forms– new membrane and cell wall material form
cell pinches in 2– 2 new cells form
what are the 3 forms of genetic recombination in bacteria
conjugation
transformation
transduction
what is conjugation?
DNA transferred from donor cell to recipient cell usually through pilus
what is transformation?
living cell acquires DNA fragments released by dead cells
what is transduction?
DNA fragments carried from one cell to another by viruses
what are the 3 shapes of bacteria
cocci
bacilli
spirilla
what are prochlorobacteriae
procloron possesses chlorophyll A and B and no Phycobilins
carotenoid pigments
adds support to the idea that chloroplasts arose as bacterial cells living within other cells
what are heterocysts
play role in N fixation
what are akinetes
play a role in resisting freezing and other adverse conditions
whats special about cyanobacteria?
can be first colonists on bare lava
can survive in fissures in desert rocks
what is the phylum bacteriophyta?
bacteria differ from archaea in RNA bases, metabolism, and lipids, many saprobes (heterotrophic)
what are autotrophic bacteria and give example
synthesize organic compounds from simple inorganic substances, No O2 produced
purple and green sulfur bacteria, purple non-sulfur bacteria
what else is special about purple and green sulfur bacteria, purple non-sulfur bacteria
use pigments and chemical pathways different from those used in cyanobacteria and in plants
what’s special about sulfur bacteria
they have bacteriochlorophyll, greenish pigment similar to chlorophyll a of higher plants
what is the chemical formula of photosynthesis in sulfur bacteria?
CO2 + 2 H2S –bacteriochlorophyll+light—-> (CH2O)n + H2O + 2S
what does sulfur bacteria do for humans
compost
what is bioremediation
use of living organisms in the cleanup of toxic wastes and pollution
bacteria that break down tri-nitro toluene, nitroglycerine
break down oil from oil spills
describe blue-green cyanobacteria
have chlorophyll a and produce oxygen
have pigments called phycobilins (role in PS) (phycoerythrin and phycocyanin)
can have carotenoid pigments
can fix N2 and produce O2
found in diverse fresh and marine habitats
how many species of algae are there
1500 known species of blue green bacteria
what color is phycoerythrin
red
what is cyanophycin
a nitrogenous food reserve that stores lipids and carbs, atypical of bacteria but some cyanobacteria form it
how do algae species form colonies?
held together by gelatinous sheath
what is kelp?
source of align used to make ice cream, salad dressing, beer, jelly beans etc
what nutrients in kelp are useful?
iodine used for goiter
nitrogen and potassium used in fertilizer
what are the uses of a diatomaceous earth quarry
filtering liquids, reflectorized paint, swimming pools, metal polishes, toothpastes, gardeners etc
what are cryptomonads?
pyrenoid associated with starch storage
2 flagella
what are dinoflagellates?
2 flagella
responsible for red tides in 40 species
what are euglena?
have an eyespot and a single flagellum
describe red algae
red to purplish in color due to presence of phycobilins similar to those of cyanobacteria
store energy in a compound called Floridian starch
produce agar and other gelatinous substances
what phylum does red algae belong to?
rhodaphyta
what are gametangia
structures where gametes are produced
what are brown algae?
kelp, algin in or on the cell wall
what pigments do brown algae have
fucoxanthin chlorophyll a and c
describe the parts of a brown algae
multicellular- specialization of function
laminarin- main food reserve
algin- carbohydrate in cell wall
what pigments do diatoms have
chlorophyll a, c1, c2 and fucoxanthin
what are diatom walls made out of and what are their food reserrves
wall consist mostly of silica in organic framework of pectin or other substances
food reserves of oil, fat or carbohydrate laminarin
what are statospores and which organisms have them
spiky thing formed by many species of golden brown algae
describe the phylum chromophyta
7600 species
food reserves
specialized pigments
describe xanthophyceae
yellow green algae
fucoxanthin absent except in vaucheria
describe vaucheria
oogamous
coenocytic
filamentous
describe sea lettuce (Ulva)
blades may be haploid or diploid up to 1 m long
multicellular with a holdfast
what is acetabularia?
mermaids win glass
marine algae
one very large cell
isogamy
what is hydrodictyon
a water net
asexual reproduction by daughter colonies
sexual reproduction is isogamous
other green algae
may have both sexual and asexual reproduction
describe the oedogonium life cycle
oogamy
sperm gains access to egg via a pore
zygote may remain dormant for up to a year before undergoing meiosis
describe spirogyra
vegetative filament
sexual reproduction by conjugation papillae form opposite each other
male gamete moves
joins female gamete to become zygote
what is special about ulothrix
haploid and diploid reproduction containing both gametes, zygotes and zoospores
describe chlamydomonas
cup shaped chloroplast
1 or 2 pyrenoids– proteinaceous structure for the synthesis of starch
eyespot that promotes movement towards light isogamy
describe the phylum chlorophyta (green algae)
diverse forms (single cell to seaweed)
diverse habitats (salt/fresh water, trees, sloths, turtles)
most common mutualistic algae is lichens
chlorophylls a and b and other pigments
store energy in starch
presumed to be ancestors of higher plants
what’s wrong with the eukaryotic kingdom classification
lack a set of unifying characteristics
what’re the current thoughts about kingdom protista
range from single cell, multicellular, colonies or filament
autotrophs (algae), heterotrophs (slime molds/protozoans ingest food, euglena does both, oomycetes and chytrids absorb food in solution)
some motile some staionary but produce motile cells
taxonomy under review
why is coleochaete a green algae presumed to be an indirect ancestor to land plants
cells that resemble parenchyma
forms a cell plate during mitosis
forms a protective covering for the zygote
produce a lignin-like compound
what does haploid mean
one set of chromosomes
gamete
what does diploid mean
2 sets of chromosomes
zygote
what does polyploid mean
more than 2 sets of chromosomes
triploid (3) navel oranges, seedless watermelons
tetraploid
what is the typical life cycle of plants that undergo sexual reproduction w/ alternation of generations (phases of life cycle)
haploid cells: go thru myosis to become spore than gametophyte than gametes then undergo fertilization to becomes DIPLOID: becomes zygote then sporophyte then sporocyte then back to meiosis
what does meiosis produce?
4 unique haploid daughter cells
