Horticulture Final Exam Study Guide Flashcards

Comprehensive vocabulary flashcards covering plant hormones, climate definitions, specialized propagation structures, and morphological anatomy from the Blinn College Horticulture Final Exam Study Guide.

Jasmonic Acid

A plant hormone involved in plant defense that regulates response to pathogens and stress; inhibits growth and seed germination; promotes flower development, fruit ripening, leaf abscission, senescence, pigment formation, and tendril coiling; triggers tuber formation; signals response to plant wounding; and mediates Induced Systemic Resistance.

Salicylic Acid

A plant hormone involved in plant growth and development, photosynthesis, transpiration, and ion uptake and transport; mediates Systemic Acquired Resistance; increases flower longevity; blocks ethylene production and inhibits germination; and blocks wound responses (commercially synthesized as aspirin).

Auxins

The first plant hormone discovered; promotes rooting; affects formation of underground tubers and bulbs; prevents fruit formation and defoliation; prevents abscission of leaves and fruits; promotes juvenility; and is synthesized in the terminal bud to suppress sprouting of axillary buds further down the stem.

Gibberellins

A plant hormone group responsible for stem elongation; breaking dormancy of seeds, buds, and tubers; increasing flower, leaf, and fruit size; and inducing flowering.

Cytokinins

A plant hormone group referred to as the "youth hormone" that works with light to increase cell division and enlargement; delays leaf abscission and slows aging; prevents chlorophyll degeneration; and stimulates bud growth.

Ethylene

A gaseous plant hormone that promotes fruit ripening; ages plant parts such as flowers; induces flowering in pineapples and members of the bromeliad family; and functions as a growth retardant.

Abscisic acid (ABA)

A plant growth retardant that may induce leaf drop and dormancy; causes stomata to close in response to drought stress; and slows elongation of stems to produce sturdier, fuller plants.

Induced Systemic Resistance

A plant defense response triggered by a pathogen or insect attack, mediated by jasmonic acid or ethylene signaling.

Systemic Acquired Resistance

A plant defense mechanism where a pathogen attack on older leaves triggers the development of resistance to that pathogen in younger leaves; mediated by salicylic acid.

Tropism

The growth or directional movement response of plants to environmental stimuli.

Phototropism

A plant's directional growth response to light.

Geotropism

A plant's directional growth response to gravity.

Thigmotropism

A plant's directional growth response to touch.

Weather

The current and temporary atmospheric conditions.

Climate

The average atmospheric conditions over a long period of time.

Macroclimate

The climate or weather conditions over a relatively large area ($24\text{--}50\text{ miles}$).

Local climate

The climate or weather conditions over a smaller localized area (such as a valley, stand of trees, open field, or the sides of a hill).

Microclimate

The climate or weather conditions over a very small area (such as inside versus outside a canopy, or the upper versus lower leaf surface).

Bulb

A specialized underground shoot storage structure consisting of a basal plate, fleshy bulb scales, lateral bulblets, a flower bud, foliage leaves, and contractile roots.

Corm

A solid, swollen underground stem base functioning as a storage organ, characterized by a stalk, new corm, cormels, old corm, new fleshy roots, and old contractile fibrous roots.

Rhizome

A thickened, horizontal underground stem capable of producing adventitious roots below and leafy shoots above, commonly propagated by cutting and division.

Tuberous Stem (Tuber)

A swollen, modified underground stem specialized for nutrient storage and vegetative propagation, characterized by buds or "eyes" from which new shoots emerge when cut into pieces.

Tuberous Root

A modified, enlarged fleshy storage root lacking nodes and internodes, which produces fibrous roots and gives rise to shoots from crown tissue.

Runner (Stolon)

A specialized horizontal aboveground stem that grows outward from the parent plant to form new rooted plantlets at its nodes, as seen in spider plants.

Node and Internode

A node is the region on a plant stem where leaves and buds attach; an internode is the section of stem between two adjacent nodes.

Monocotyledon vs. Dicotyledon Seed Structure

Monocot seeds (e.g., corn) contain a single cotyledon with an embryo and a large endosperm enclosed in a seed coat; dicot seeds (e.g., lima bean) contain two cotyledons surrounding the embryo.

Leaf Anatomy

The structural parts of a typical plant leaf, which include the stem, leaf axil, petiole, leaf base, axillary bud, stomata, leaf margin, blade, midvein, leaf apex, and leaf covering.

Flower Anatomy

The principal parts of a complete flower, consisting of the sepal, petal, corolla, stamen (composed of the anther and filament), and pistil (composed of the stigma, style, pollen tube, ovary, and ovule).