Plant Biology and Crop Science Flashcards

Vocabulary flashcards covering core plant biology concepts, plant anatomy, physiological processes, crop development stages, and crop domestication history based on lecture notes.

Woody Perennial

A plant type that maintains previous years' growth and continues building structure, where aboveground wood remains while leaves are lost annually.

Growth (Plant Biology)

The amassing or increase in dry weight or size of an organism due to an increase in the number of cells.

Development (Plant Biology)

The allocation of dry weight or differentiation to plant organs as plants transition through developmental phases such as germination, seedling, vegetative, flowering, and seed maturation.

Phytomer

The basic structural unit of the aboveground portions of a plant, consisting of a leaf, a node, an internode, and an axillary bud.

Etoliation

The elongation of stems that occurs when plants compete for light, leading plants to expend energy supporting taller growth.

Long-day Plants

Plants that initiate flower production when a critical daylength (short night) is reached, which may be obligate or facultative.

Short-day Plants

Plants that initiate flower production when a critical daylength is returned to (requiring long nights).

Day-neutral Plants

Plants that exhibit no photoperiodic response for flower initiation, relying instead on developmental stage.

Vernalization

A cold temperature and/or short day treatment required by winter annuals and perennials prior to the initiation of flower primordia.

Heterotrophic Stage

The initial stage of seedling development spanning from seed imbibition through leaf emergence through the coleoptile.

Transition Stage

The second stage of seedling development that begins with the start of photosynthesis and continues through the expenditure of seed reserves.

Autotrophic Stage

The final stage of seedling development in which photosynthesis alone supplies all carbon sources to the plant.

Epigeous Emergence

A form of seed emergence in dicots where elongation of the hypocotyl pulls the cotyledons above the soil surface.

Hypogeous Emergence

A form of seed emergence in dicots where the epicotyl elongates while the cotyledons remain beneath the soil surface.

Germination

The emergence of a radicle and shoot from a seed when environmental conditions and internal seed readiness are met.

Emergence

The stage of plant development when the shoot becomes visible above the soil surface.

Photoautotrophs

Organisms that use light energy from the sun to synthesize organic molecules and produce their own food.

Heterotrophs

Organisms that cannot synthesize their own food and must obtain energy and nutrition by consuming other organisms.

Photosynthesis

The biological process by which plants convert light energy into chemical energy stored in organic compounds: $ATP\text{ energy} + 12H_2O + 6CO_2 \rightarrow 6O_2 + 6H_2O + C_6H_{12}O_6$.

Transpiration

The evaporation and loss of water from plant tissues into the atmosphere.

Evapotranspiration

The combined total loss of water from both soil evaporation and plant transpiration.

Xylem

Vascular tissue that transports water and dissolved mineral nutrients unidirectional upward from the roots to the rest of the plant.

Phloem

Vascular tissue that transports photosynthetic sugars and other organic compounds multidirectionally throughout the plant.

Meristem

Regions of actively dividing, undifferentiated cells responsible for plant growth and development located in roots, stems, leaves, and flowers.

Apical Meristem

A meristem located at the tip of a shoot or root responsible for primary elongation growth.

Axillary Bud

A meristematic bud located at the node in the axil of a leaf that is capable of developing into vegetative branches or tillers.

Tap Root System

A root system characteristic of dicots in which a single main primary root remains dominant over secondary branching roots.

Fibrous Root System

A root system characteristic of monocots consisting of a network of secondary roots that are uniform in size with no dominant main root.

Stolon

An aerial modified stem that grows horizontally along the surface of the ground.

Rhizome

A subterranean modified stem consisting of horizontal, spreading shoots near the soil surface.

Tuber

An enlarged subterranean stem modified for nutrient storage and vegetative reproduction, such as in potatoes.

Symbiosis (Crop Domestication)

A mutually beneficial relationship between two organisms, such as humans providing cultivated crops with managed growth environments while crops supply humans with food.

Centre of Origin

The geographic region where a crop species was originally domesticated and where its greatest genetic diversity resides, as theorized by Nikolai Vavilov.

Heliotropism

The solar tracking mechanism in plants, driven by circadian differential stem elongation over 24 hours to maximize light interception.

Perfect Flower

A flower that contains both male (stamens) and female (pistil/carpel) functional reproductive structures.

Monoecious

A plant species possessing separate male and female imperfect flowers located on different parts of the same individual plant.

Dioecious

A plant species having distinct male and female imperfect flowers located on separate individual plants.

Operation LIFT

A 1970 Canadian government program ('Lower Inventories For Tomorrow') that compensated farmers $6 per acre for summerfallow to reduce oversupplied wheat acreage.

Summerfallow

An agricultural practice of leaving cropland unseeded for an entire growing season while managing weeds via tillage or herbicides to conserve moisture.

Triangle of U

A genomic model published by Nagahura U (Jang-choon Woo) in 1935 demonstrating the evolutionary and hybridization relationships between diploid and allotetraploid Brassica species.

Red Fife

A notable hard red spring wheat variety selected in Ontario in 1842 from Polish seed, known for its high grain quality despite late maturity.

Marquis

A landmark Canadian hard red spring wheat variety bred by Sir Charles E. Saunders from Hard Red Calcutta × Red Fife, released in 1909 as a quality benchmark.

Tower (Canola)

The first official canola variety (low erucic acid, low glucosinolate Brassica napus), developed by Dr. Baldur Stefansson at the University of Manitoba and released in 1974.