HORT 301 Master set
This type of dormancy is removed by accumulation of chilling.
Endodormancy
In the case of "normal" sexual development of seeds, __________ develops solely from the union of a sperm cell with two polar nuclei.
Endosperm
Why are entomophilous plants showier and have higher nectar content than anemophilous plants?
Entomophilous plants (ent - insect, philous - affinity) need to attract insects for reproduction, so it is advantageous for them to be more dramatic and have a high food supply for insects.
Most angiosperms exhibit what sort of pollen dispersal?
Entomophily
Cotyledons are the primary energy source during germination for which type of seed?
Exalbuminous
Trees start out early on in their life with ___________ growth, during which time they develop a trunk.
Excurrent
Juvenile plants produce more short shoots than long shoots. True or False?
False
T/F Histogenic layers are only present when mitosis is very active.
False
T/F Most conifers have BOTH latent buds and adventitious buds.
False
T/F Seed are not capable of sensing light before germination.
False
T/F If a plant has a reported cold hardiness based on lab tests of -45 °C, that means that it will never be damaged unless it gets that cold.
False, the plan must be properly acclimated to achieve that level of hardiness
In general, increasing temperatures above some minimum will cause plants to ___________.
Flower sooner
Heterophyllus shoots are only found in ___________.
Free growth species
The lowering of the freezing point by a few degrees due to increased solutes is ____________________.
Freezing point depression
What do you think is the likely histogenic layer makeup of the plant in the figure below? ONLY CONSIDER THE LEAVES WITH LARGE CENTER REGIONS OF YELLOW. Use "G" to indicate Green and "Y" to indicate yellow and provide an indication for all three histogenic layers.
GGY
__________ promotes germination of seeds and can sometimes overcome dormancy that normally requires chilling.
Gibberellin
________ induces synthesis of hydrolytic enzymes (hydrolases) into the endosperm that break down macromolecules to be used by the embryo in germination.
Gibberellins
The ultimate fate of cells in the embryo with regard to which tissue layer they will be a part of is already determined by the ______________.
Globular stage
________ are plants adapted to saline soils and can tolerate and grow in high salt situations.
Halophytes
Gametes, regardless of organism or ploidy level, are ________.
Haploid
If you are developing an integrated pest management program, it would be most effective to use _______ to estimate pest activity and development.
Heat summation
____________ is used to quantify the relationship between temperature and growth and development.
Heat summation
_______________ is a spatial separation of anthers and stigma within the same flower.
Herkogamy
The most rapid water uptake during seed development occurs during _______.
Histodifferentiation
In order for ice to form, the temperature must be low enough and there must be ________, which serve to orient water molecules.
Ice Nucleators
Colorado blue spruce has the genetic potential to be hardy to -50 °F. That means that....
It has the potential to be damaged at warmer temperatures if it is not acclimated
Intermediate physiological dormancy species like cedars may not definitively require cold stratification but most producers will stratify. Why?
It improves germination rate and uniformity
Explain why high salt levels in the seedbed often results in poor seed germination.
It's down to chemistry. The salt content can cause a change in the soil's influence when it comes to osmosis. If the amount of salt outside the seed is higher than inside of the seed, moisture will move from the plant to concentrate where the salt is. Most life forms on earth need water, so this is no good.
You are talking to a grass seed grower in Linn County. She has a very advanced system of irrigation and does a great job of weed and pest management. She decided to opt for using straight urea as her fertilizer because she learned that nitrogen generally is the key nutrient that is limiting. She decided against a soil analysis even though this plot was previously shown to have very little plant available potassium. Over the past two years she has seen her yields decline precipitously. Explain to her in one short sentence why she will never realize her crops' full potential unless she changes her soil management. Hint: Recall the slide with the barrel slats.
K is the limiting factor.
Which process is affected first by a drought stress? Photosynthesis Respiration Leaf expansion Anthesis
Leaf Expansion
Phytochrome is involved in ______________.
Long term processes that affect overall plant growth (photomorphogenesis) Short term processes like flowers bending toward light (phototropism) Sensing the day length (photoperiodism) to regulate flowering, bud set, etc.
Sites of cell division are called ________.
Meristems
What are the four factors required for successful cold stratification?
Moisture, temperature, time, and aeration
Mitosis occurs in meristems and serves primarily to provide _________.
More cells
At horticultural maturity, are all fruits physiologically mature?
No, horticultural maturity is independent of physiological maturity
I have propagated a pear tree that is flowering (means it's adult). After propagating it, the next year it doesn't flower so I decide to hit it with a high rate of nitrogen and irrigate heavily. Am I going to get this plant to flower quicker?
No, vegetative adult trees will flower sooner if growth is restricted.
Which type of freezing is more damaging to plants?
Non-equilibrium freezing
"Age of plants" can be described in terms of both _________ and ___________.
Ontogeny and chronology
The _________ will become the seed following fertilization.
Ovule
Apical dominance is a type of ______________.
Paradormancy
Most flowering plants (90% or so) have exhibit what sort of sex expression?
Perfect flowers
Which type of chimera is the most stable?
Periclinal
The arrangement of leaves around the stem is referred to as ____________.
Phyllotaxy
Topophysis is usefully exploited during propagation of fruiting trees to establish orchard because ____.
Physiologically mature materials remain mature and there is a reduced time period to flowering and fruit production.
_________________ is responsible for sensing light including photoperiod to enter dormancy.
Phytochrome
Endogenous regulation of plant development generally involves _____________.
Phytohormones
Monitoring plant growth and development is important because
Plants respond differently to cultural practices at different stages of growth and development
During pollination...
Pollen is transferred to the stigma
At a certain temperature, there are equal amounts of CO2 fixed by photosynthesis and released by respiration. This is called the _______ and above this temperature, there is more CO2 released by respiration than fixed by photosynthesis.
Temperature compensation point
Species with buds that have endodormancy can only resume after:
They receive sufficient chilling
The ability of cells in the shoot apical meristem to differentiate into any organ in the plant is referred to as _______________.
Totipotency
When preparing for dormancy, nutrients within leaves primarily:
Translocate to storage organs
Ability of stem cuttings to form adventitious roots decreases as plants mature. True or False?
True
Day neutral plants' flowering and timing is unaffected by photoperiod. True or False?
True
Plants of the same species but of different provenance are often triggered to enter dormancy by different day lengths (earlier vs later in the season). True or False?
True
If you wanted to collect material from a seedling cherry tree that is reproductively mature, graft it, and have it begin flowering as quickly as possible, where would you collect scion?
Upper branches
Phase change in woody plants represents the change from _______________.
Vegetative growth to reproductive growth.
To overcome morphological dormancy one would ________.
Warm stratify
Cell division generally ends ________ in fruit development. By 75% of the time it takes to mature Around physiological maturity Pre-anthesis Within a week or so after anthesis (short duration)
Within a week or so after anthesis (short duration)
Chronology
___________ is the simplest method to predict growth and development of plants to coordinate timing of application of cultural practices.
In an annual plant, during both early and late stages of growth there is _______.
more energy devoted to vegetative growth early, then later switching to reproductive growth after the phase change.
Which fruit will have a higher sugar content per fruit, fruit collected from a plant cropped to 150 lbs/tree or one cropped to 300 lbs/tree?
150 lbs/tree
In order to get my warm season (threshold 50 °F) corn to ripen last summer in Corvallis, I started my plants in the greenhouse and grew them for 25 days under temperatures of 75 °F day/65 °F night. Once I move it to my garden, the temperatures over the next month (30 days) averaged 77 °F high/52 °F low. In my production guide, it states that this cultivar ('Silver Queen') requires 1500 GDD to mature. Will my 'Silver Queen' ripen during this period? To get full credit, provide the number of GDD that will accumulate and show your work.
75+65=140/2 = 70 - 50 = 20 GDD*25days = 500GDD 14.5GDD * 30 = 435 GDD total 935.
Mature leaves perceive the shortening day length and produce _________, which leads to photoperiod-induced bud dormancy.
Abscisic Acid
What hormone is associated with sensing and messaging a plant is under drought stress? Auxin Gibberellin Abscisic acid Ethelene
Abscisic acid
________ is the treatment or time required after harvest in dry storage to break dormancy exhibited in freshly harvested seeds. Intensity of dormancy decreases during storage.
After ripening
Early leaves are present in the buds of ______________, while late leaves are only found in _______________
All shoots, long shoots
________ plants grow vegetatively, flower, produce seeds, then senesce and die over a single season.
Annual
Trees exhibit __________, which extends over much of its life and results in its characteristic shape.
Apical control
Within a "typical" seed at maturity there will be an embryo that has _______,______________ ,and __________________.
Apical-basal patterning Radial patterning Root and shoot meristems
Consumers may prefer parthenocarpic fruit because they ____.
Are seedless
Modifications were made in calculating degree days (heat units) to result in a new unit called growing degree days. Why were these modifications made?
As temperature increases, the rate of growth and development eventually stops increasing
Leaf primordia are added to the shoot apex where there are sufficient levels of
Auxin
______ moves to the shaded side of stems in plants and results in phototropism.
Auxin
As an annual plant approaches senescence it ____________.
Begins programmed cell death of all tissues but seeds
What type of light is present in sunlight?
Both red and Far-Red
More than 90% of the dry weight of a plant is composed of ________.
Carbon, hydrogen, oxygen
Growth of new cells takes place when they enlarge due to water uptake following mitosis. This takes place because new cells can loosen their ___________ and expand.
Cell Wall
Since cell division is very short in fruit development, what is responsible for the majority of fruit growth?
Cell enlargement
After cells divide they enlarge, mainly as a function of turgor pressure (water uptake). Why is drought stress such an issue at this time? Can a plant FULLY recover if it experiences drought stress during cell enlargement? Briefly explain.
Cell walls become rigid and no longer have the elasticity to enlarge.
An example of exogenous regulation of plant development may involve ____.
Day length (photoperiod)
The process that produces a zygote from the union of a sperm and egg cell and endosperm from the union of a sperm and two polar nuclei is called ____________.
Double fertilization
The number of leaves produced during the growing season in fixed growth species is determined ____________.
During the previous season
Grass in the Willamette Valley tends to stop growing during summer unless it is irrigated. What type of dormancy is this?
Ecodormancy
This is the type of dormancy exhibited by roots of woody plants.
Ecodormancy
Salinity of water or potting media is determined by measuring _______.
Electrical Conductivity
If a seed remains "dormant" until it is given proper temperature, air, moisture, etc. but otherwise requires no pretreatment for germination it is/exhibits_______.
Quiescent
Orthodox seeds dry down to low moisture content (<10%) whereas _____ seeds become inviable if they dry down.
Recalcitrant
Species that set a resting terminal bud in between multiple flushes of vegetative growth during the growing season exhibit ______
Recurrent growth
Plants absorb ______ light, which creates a high concentration of ______ light under a vegetative canopy like you would encounter on the floor of a dense forest.
Red, far-red
Apical dominance can be overcome by _________________.
Removing the apical meristem
In a seed with combinational dormancy in the form of hardseededness and deep physiological dormancy, what needs to be done to promote germination?
Scarify then cold stratify
Define each of the following: Skotoperiod: Obligate vernalization plant: Facultative vernalization plant: Obligate short day plant: Facultative short day plant:
Scotoperiod - a length of time when something is in the dark (ie me when it comes to economics). Obligate vernalization plant - a plant that needs to have a certain level of cold for a certain length of time as a seedling to make it flower. Facultative plants pop out flowers early when it is cold. Obligate short-day plants need a short day length to flower, and facultative short day plants flower with indiscriminate day lengths and earlier with shorter days.
Water logged soils are a particular issue during seed germination because ___.
Seeds have a high rate of respiration during germination
The stages of plant development are regarded as ________.
Sequential
Cold acclimation in woody plants generally starts with _________. Shortening day length with warm temperatures Shortening day length with freezing temperatures Diurnal freezing, independent of day length Increasing day length, freezing temperatures
Shortening day length with warm temperatures
Growth rate of annual plants over the duration of a year is ________ when plotted on a graph (growth rate on y-axis and time on x-axis).
Sigmoidal
Thornless blackberries resulted from a mutation in the L-I histogenic layer. A viable way to propagate a plant that would result in more thornless plants would be:
Stem cuttings/layers
The ______ holds the developing embryo in place and provides some nutrients from the mother plant.
Suspensor
Dichogamy encourages outcrossing by having a _________ separation between male and female activity/receptivity.
temporal
