This site is 100% ad supported. Please add an exception to adblock for this site.

Ch. 39

Terms

undefined, object
copy deck
photoperiodism
a physiological response to day length, such as flowering in plants.
cytokinins
a class of related plant hormones that retard aging and act in concert with auxins to stimulate cell division, influence the pathway of differentiation, and control apical dominance.
senescence
the biological processes of a living organism approaching an advanced age (i.e., the combination of processes of deterioration which follow the period of development of an organism). The word senescence is derived from the Latin word senex, meaning "old man" or "old age" or "advanced in age"
short-day period
a plant that flowers, usually in late summer, fall, or winter, only when the light period is shorter than a critical length.
critical night length
the length of darkness that must be exceeded by short-day plants, or not exceeded by long-day plants, for flowering to be initiated
thigmotropism
the directional growth of a plant in relation to touch.
circadian rhythm
a physiological cycle of about 24 hours that is present in all eukaryotic organisms and that persists even in the absence of external cues.
gravitropism
a response of a plant or animal in relation to gravity.
auxins
a class of plant hormones, including indoleactic acid (IAA), having a variety of effects, such as phototropic response through the stimulation of cell elongation, stimulation of secondary growth, and the development of leaf traces and fruit
phytochromes
a pigment involved in many responses of plants to light.
long-day period
a plant that flowers, usually in late spring or early summer, only when the light period is longer than a critical length.
hormones
any one of the many circulating chemical signals found in all multicellular organisms that are formed in specialized cells, travel in body fluids, and coordinate the various parts of the organism by interacting with target cells
gibberellin
a class of related plant hormones that stimulate growth in the stem and leaves, trigger the germination of seends and breaking of bud dormancy, and stimulate fruit development with auxin.
phototropism
growth of a plant shoot toward or away from light
tropism
a growth response that results in the curvature of whole plant organs toward or away from stimuli due to differential rates of cell elongation.
Abscisdic acid (ABA)
a plant hormone that generally acts to inhibit growth, promote dormancy, and help the plant tolerate stressful conditions.

Deck Info

16

permalink