General Botany: Plant Anatomy, Physiology, and Development Flashcards

Flashcards covering plant tissue systems, organs, diversity, physiological processes, cellular respiration, nutrition, hormones, and light responses based on the General Botany module.

Tissue

A group of similar cells that join forces to perform a specific job in a plant or organism.

Ground Tissue

A versatile plant tissue system forming the bulk of the plant structure that supports growth, stores nutrients, and facilitates photosynthesis.

Parenchyma

A type of ground tissue with thin cell walls and large central vacuoles that functions in food and water storage, photosynthesis, and tissue repair.

Collenchyma

A type of ground tissue with unevenly thickened cell walls that provides flexible structural support to young and growing plant parts.

Sclerenchyma

A rigid ground tissue characterized by thick, lignified cell walls that provides mechanical strength and protection to mature plant parts.

Vascular Tissue

Specialized plant tissue arranged in bundles that functions as an internal transport system moving water, minerals, and sugars throughout the plant.

Xylem

Vascular tissue composed of tracheids and vessel elements that conducts water and dissolved minerals upward from the roots to the leaves.

Phloem

Vascular tissue composed of sieve tube elements and companion cells that transports sugars and nutrients bidirectionally throughout the plant.

Dermal Tissue

The outermost protective tissue layer of a plant that guards against physical damage, pathogens, and excessive water loss.

Epidermis

The outermost single layer of cells forming a protective covering over leaves, stems, and roots.

Cuticle

A waxy, waterproof coating secreted on the surface of the epidermis that minimizes water evaporation and protects against environmental stress.

Stomata

Microscopic pores located on plant surfaces, mainly the underside of leaves, that facilitate gas exchange ($CO_2$ and $O_2$) and transpiration.

Guard Cells

Specialized epidermal cells surrounding each stoma that regulate its opening and closing to control water loss and gas exchange.

Trichomes

Hair-like projections extending from the leaf or stem epidermis that deter herbivores, reflect sunlight, and reduce water loss.

Embryonic Tissue (Meristematic Tissue)

Plant tissue consisting of undifferentiated, actively dividing cells responsible for continuous growth and the formation of new plant organs.

Apical Meristem

Meristematic tissue located at the tips of roots and shoots responsible for primary growth, increasing the plant's length or height.

Intercalary Meristem

Meristematic tissue located at the nodes or internodes of monocot stems that allows rapid elongation of leaves and stems.

Lateral Meristem

Meristematic tissue (vascular cambium and cork cambium) running parallel to the sides of stems and roots that drives secondary growth in girth.

Meristematic Tissues by Position

Anatomical classification showing apical meristem at shoot/root tips, intercalary meristem at internodes, and lateral meristem along stem width.

Taproot System

A root system characterized by a single prominent main root growing deep into the soil with smaller lateral branches, typical of dicot plants.

Fibrous Root System

A root system composed of a dense, highly branched network of thin roots located close to the soil surface, typical of monocot plants.

Root Cap

A thimble-shaped protective structure covering the tip of the root that shields the apical meristem from friction as the root penetrates soil.

Root Regions Diagram

A longitudinal cross-section depicting the root cap, area of cell division, area of elongation, and area of maturation with root hairs.

Casparian Strip

A waxy barrier of suberin in the cell walls of the endodermis that forces water and solutes to pass through plasma membranes before entering the vascular cylinder.

Apoplastic Pathway

A pathway for water movement through non-living parts of the root, including cell walls and intercellular spaces, without crossing cell membranes.

Symplastic Pathway

A selective pathway for water movement from cell to cell through the living cytoplasm via plasmodesmata channels.

Internal Leaf Structure

A cross-section diagram showing the cuticle, epidermis, palisade mesophyll, spongy mesophyll, xylem, phloem, and stomata with guard cells.

Petiole

The stalk that connects the leaf blade (lamina) to the stem, facilitating nutrient and water transport between them.

Simple Leaf

A leaf that features a single, continuous, undivided blade attached to the stem by a single petiole.

Compound Leaf

A leaf whose blade is divided into multiple smaller distinct leaflets attached to a single main petiole.

Flower Anatomy

Structural visual of an idealized flower showing the pistil/carpel (stigma, style, ovary, ovule), stamen (anther, filament), petal, sepal, and receptacle.

Complete Flower

A flower that contains all four major floral whorls: sepals, petals, stamens, and carpels/pistils.

Perfect Flower

A flower that possesses both male (stamens) and female (carpels/pistils) functional reproductive organs.

Actinomorphic (Radial Symmetry)

A floral symmetry type where the flower can be divided into equal halves along multiple radial planes through the center.

Zygomorphic (Bilateral Symmetry)

A floral symmetry type where the flower can be divided into equal mirror-image halves along only one vertical plane.

Inflorescence

The structural arrangement or cluster of multiple flowers on a single plant stem.

Pericarp

The tissue wall of a fruit derived from the matured ovary wall, typically consisting of epicarp, mesocarp, and endocarp layers.

Endosperm

A nutrient-rich tissue formed inside the seed that nourishes the developing plant embryo during germination.

Photosynthesis

The biochemical process by which green plants convert light energy, carbon dioxide ($CO_2$), and water ($H_2O$) into glucose ($C_6H_{12}O_6$) and oxygen ($O_2$).

Calvin Cycle

The light-independent stage of photosynthesis occurring in the chloroplast stroma that fixes $CO_2$ using ATP and NADPH to produce glucose.

Transpiration

The loss of water vapor from the aerial parts of a plant, primarily through the stomata on the leaves.

Guttation

The exudation of liquid water droplets from hydathodes along leaf margins due to root pressure during periods of high humidity and low transpiration.

Glycolysis

The initial anaerobic stage of cellular respiration in the cytoplasm that breaks down one glucose molecule into two pyruvate molecules, generating a net yield of $2\text{ ATP}$ and $2\text{ NADH}$.

Pyruvate Oxidation

The transition step in the mitochondrial matrix that converts pyruvate into acetyl-CoA, releasing $CO_2$ and producing $NADH$.

Citric Acid Cycle (Krebs Cycle)

A metabolic pathway in the mitochondrial matrix that oxidizes acetyl-CoA to produce $CO_2$, $ATP$, $NADH$, and $FADH_2$.

Oxidative Phosphorylation

The final stage of aerobic respiration in the inner mitochondrial membrane where the electron transport chain and chemiosmosis generate the majority of cell $ATP$.

Chemiosmosis

The process by which the flow of protons ($H^+$) down an electrochemical gradient through ATP synthase powers the synthesis of $ATP$.

Macronutrients

Essential mineral elements required by plants in large amounts for vital functions, including nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur.

Micronutrients

Essential mineral elements required by plants in trace amounts, including iron, manganese, zinc, copper, and molybdenum.

Auxin

A plant growth promoter hormone synthesized in shoot tips that stimulates cell elongation, apical dominance, and phototropism.

Gibberellins

Plant hormones that promote stem elongation, break seed dormancy to induce germination, and stimulate fruit growth.

Cytokinins

Plant hormones synthesized primarily in roots that stimulate cell division, promote shoot development, and delay leaf senescence.

Abscisic Acid (ABA)

A stress-responsive plant hormone that induces seed dormancy and triggers stomatal closure during drought to conserve water.

Ethylene

A gaseous plant hormone that accelerates fruit ripening, regulates leaf abscission, and promotes plant senescence.

Jasmonates

Plant defense hormones synthesized upon wounding or pest attack to activate secondary metabolites and proteinase inhibitors.

Traumatic Acid

A wound hormone synthesized in damaged plant tissues that stimulates meristematic activity to heal injuries.

Florigen

A proteinaceous flowering signal synthesized in leaves under favorable day-length conditions that translocates to the shoot apical meristem to initiate blooming.

Photoperiodism

The physiological response of plants to the relative lengths of light and dark periods in a 24-hour cycle, regulating processes such as flowering.

Phytochrome

A light-sensitive photoreceptor protein switching between inactive ($P_r$) and active ($P_{fr}$) forms to regulate seed germination, flowering, and shade avoidance.

Vernalization

The acquisition of a plant's ability to flower or germinate by prior prolonged exposure to cold temperatures.