Growth and Development Flashcards
Irreversible increase in mass due to division and enlargement of cells
Growth
Plant grows, stops growing and dies in one season
Determinate growth
Plant or parts of plant grow and continue to be active for several to many years
Indeterminate growth
Cells develop different forms adapted to specific functions
Differentiation
Coordination of growth and differentiation of a single cell into tissues and organs
Development
Furnish elements and energy for plant growth and maintenance
Nutrients
Nutrients are obtained from ?
air and soil
Organic molecules that participate in catalyzed reactions, mostly by functioning as electronacceptors or donor
Vitamins
Production dictated by genes
Hormones
can be used to measure hormone concentrations
Bioassays
occurs mainly in apical meristems, buds, young leaves and actively growing parts of plants
Auxin
Promotes thicker, stronger flower stalks
Gibberellins
Stimulants to cell division
Cytokinins
Has inhibitory effect on stimulatory effects of other hormones
Abscisic Acid (ABA)
- Produced by fruits, flowers, seeds, leaves and roots
- Produced from amino acid methionine
- Can trigger its own production
Ethylene
Released from cell walls by enzymes - Influence cell differentiation, reproduction, and growth in plants
Oligosaccharins
Bind to receptors on cell surfaces. Affect apical dominance, gravitropism, seed germination
Brassinosteroids
Suppression of growth of lateral (axillary) buds
Apical dominance
Breakdown of cell components and membranes, eventually leading to death of cell
Senescence
Result from varying growth rates in different parts of an organ
Growth movements
Spiraling movements not visible to eye
Nutations
Side-to-side oscillations
Nodding movements
Visible spiraling in growth
Twining movements
Non-directional movements
Nastic movements
Permanent downward bending
Epinasty
Permanent movements resulting from external stimuli
Tropisms
Organ receives greater stimulus on one side
Initial perception
One or more hormones become(s) unevenly distributed across organ
Transduction
Result of greater cell elongation on one side
Asymmetric growth
Growth movement toward (+) or away (-) from light
Phototropism
Growth responses to stimulus of gravity
Gravitropism
Positively gravitropic
Primary roots
Negatively gravitropicUsed to negate the effects of gravity. A chamber in which seedlings are grown.
Clinostat
Contact with solid object
Thigmotropism
Tropism that is affected by chemicals
Chemotropism
Tropism that is affected by temperature
Thermotropism
Tropism that is affected by Wounding
Traumotropism
Tropism that is affected by Electricity
Electrotropism
Tropism that is affected by Dark
Skototropism
Tropism that is affected by Oxygen
Aerotropism
Result from changes in internal water pressures and often initiated by contact with objects outside of plant
Turgor movements
Special swellings at base of leaf
Pulvini
Leaves often twist on their petioles in response to illumination and become perpendicularly oriented to light source
Heliotropism (Solar tracking)
Movement that involves entire plant or reproductive cell
Taxes (taxic movement)
Length of day (night) directly related to onset of flowering
Photoperiodism
Will not flower unless day length is shorter than a critical period
Short-day plants
Will not flower unless periods of light are longer than a critical period
Long-day plants
Will not flower if days too short, or too long
Intermediate-day plants
Will flower under any day-length, provided there is minimum amount of light necessary for normal growth
Day-neutral plants
Pigments that control photoperiodism
Phytochromes
Absorbs red light
Pr
Absorbs far-red light
Pfr
Blue, light-sensitive pigments that play a role in circadian rhythms and interact with phytochromes to control reactions to light
Cryptochromes
Optimum night and day temperatures
Thermoperiod
Period of growth inactivity in seeds, buds, bulbs, and other plant organs even when temperature, water, or day length would typically cause growth
Dormancy
State in which seed cannot germinate unless environmental conditions normally required for growth are present
Quiescence
Factors that control change from dormancy to germination in seeds
After-ripening
Artificially breaking dormancy
Stratification
