Plant Physiology Flashcards

Flashcards covering key vocabulary from the Plant Physiology lecture.

Shoot system

Vegetative parts (leaves and stems) and reproductive parts (flowers and fruits)

Root system

Supports the plant and absorbs water and minerals

Meristematic tissue

Cells that constantly divide for plant growth

Permanent tissue

Cells that are no longer actively dividing

Apical meristems

Tips of stems and roots; responsible for lengthening

Lateral meristems

Growth in thickness or in a maturing plant

Intercalary meristems

Monocots at the base of leaf blades

Dermal tissue

Covers and protects the plant

Vascular tissue

Transports water

Ground tissue

Photosynthesis, provides a supporting matrix for the vascular tissue, and helps to store water and sugars

Monocot stems

Vascular bundles scattered throughout ground tissue

Dicot stems

Vascular bundles arranged in a ring

Parenchyma cells

Living cells found in stem, root, leaf interior, and fruit pulp; responsible for metabolic functions and wound repair; store starch

Collenchyma cells

Elongated cells with unevenly thickened walls that support stem and leaves; alive at maturity

Sclerenchyma cells

Provide support but are often dead at maturity; have secondary cell walls thickened with lignin deposits

Nodes

Points of attachment for leaves, aerial roots, and flowers

Internodes

Stem regions between two nodes

Petiole

Stalk extending from stem to leaf base

Axillary bud

Between leaf base and stem; can give rise to branches or flowers

Epidermis

Single layer of cells covering and protecting the underlying tissue of a stem

Bark

Tough, waterproof outer layer of woody plants

Trichomes

Hairlike structures on epidermal surface; help to reduce transpiration, increase solar reflectance, and store compounds

Pith

Ground tissue interior to vascular tissue in stems; soft, spongy parenchymal cells that store nutrients, provide support, and aid in nutrient transport

Cortex

Layer between vascular tissue and epidermis in stems; stores carbohydrates, aids transport to roots, provide structural support

Primary growth

Increase in shoot length; shoot apical meristem activity

Secondary growth

Increase in thickness (girth); lateral meristem activity

Lenticels

Openings in periderm for gas exchange

Stolons

Stems running parallel to or just below ground surface

Runners

Above-ground stolons producing clone plants at nodes (e.g., strawberries)

Tubers

Modified stems storing starch (e.g., potatoes)

Bulbs

Underground storage units with fleshy leaves (e.g., onions)

Tendrils

Slender, twining strands for climbing support

Thorns

Sharp outgrowths for plant protection

Tap root

Main root that grows down vertically with many smaller lateral roots; penetrates deep into the soil; used by dicots

Fibrous root

Located closer to the soil surface and forms a dense network of roots; used by monocots

Zone of cell division

Closest to the root tip; actively dividing cells of root meristem

Zone of elongation

Where newly formed cells increase in length, lengthening the root

Zone of maturation/differentiation

Starts at the first root hair; where cells differentiate into special cell types

Root hairs

Extensions of root epidermal cells that aid absorption of water and minerals

Lamina

Leaf blade

Petiole (leaf)

Attaches leaf to stem

Stipules

Small, green appendages at base of petiole

Midrib

Central vein branching into smaller veins

Stomata

Openings in epidermis for gas exchange; surrounded by two guard cells to regulate opening and closing

Cuticle

Waxy layer covering the leaf's surface

Palisade parenchyma

Column-shaped, tightly packed cells in mesophyll

Spongy parenchyma

Loosely arranged cells of irregular shape in mesophyll; allows gas exchange

Xylem (leaf)

Transports water in leaves

Phloem (leaf)

Transports photosynthetic products in leaves

Transpiration

Loss of water through evaporation at the leaf surface

Photomorphogenesis

Growth and development of plants in response to light

Photoperiodism

Ability to use light to track time

Phototropism

Grow toward or away from light

Gravitropism

Roots grow into soil (positive) and shoots grow toward sunlight (negative)

Auxins

Cell elongation

Cytokinins

Promote cell division

Gibberellins

Shoot elongation, seed germination and fruit and flower maturation

Ethylene

Fruit ripening

Abscisic acid

Inhibits stem elongation; shuts things down during times of environmental stress

Thigmotropism

The movement of a plant due to directional pressure

Thigmonastic response

A touch response independent of the direction of stimulus

Thigmomorphogenesis

Slow developmental change in the shape of a plant subjected to continuous mechanical stress