Untitled Flashcards Set

Xylem Sap Movement

The movement of water and dissolved minerals from roots to leaves in vascular plants, facilitated by root pressure and transpiration pull.

Transpiration Pull

The process by which water is pulled up through plants due to the loss of water vapor from leaves.

Root Pressure

The pressure created in the roots of plants that helps push water upward through the xylem.

Cohesion

The property of water molecules to stick together through hydrogen bonding, essential for transport in plants.

Adhesion

The property of water molecules to adhere to the walls of xylem vessels, aiding in the upward movement of water.

Phloem Sap

The fluid that moves sugars and nutrients through the phloem from sources to sinks in plants.

Hydrostatic Pressure

The pressure generated within the phloem due to high sucrose concentration that aids in the movement of phloem sap.

Stomata

Small openings on plant leaves regulated by guard cells, facilitating gas exchange and transpiration.

Guard Cells

Specialized epidermal cells that control the opening and closing of stomata.

Gibberellin (GA)

A plant hormone that stimulates seed germination and growth by promoting the production of enzymes.

Auxin

A plant hormone that regulates growth, particularly in relation to phototropism and apical dominance.

Abscisic Acid (ABA)

A plant hormone that promotes stomatal closure and dormancy in plants.

Ethylene

A gaseous plant hormone that regulates fruit ripening and leaf senescence.

Nitrogen-Fixing Bacteria

Microorganisms that convert atmospheric nitrogen (N2) into forms usable by plants, such as ammonium (NH4+).

Mineral Nutrients

Essential elements required by plants for growth and development, excluding carbon, hydrogen, and oxygen.

Homeostasis

The maintenance of stable internal conditions in an organism, which is vital for survival.

Action Potentials

Rapid electrical signals that propagate along the axon of a neuron, allowing for communication within the nervous system.

Saltatory Conduction

The process by which action potentials jump between nodes of Ranvier in myelinated axons, increasing transmission speed.

Phototransduction

The process by which photoreceptor cells in the retina convert light stimuli into electrical signals.

Neuromuscular Junction

The synapse between a motor neuron and a skeletal muscle fiber, where neurotransmitters stimulate muscle contraction.

Sliding Filament Theory

The explanation of muscle contraction where actin filaments slide past myosin filaments, shortening the muscle.

Vasoconstriction

The narrowing of blood vessels to reduce blood flow and conserve body heat.

Feedback Regulation

Mechanisms that regulate physiological processes, including negative feedback (stabilizing) and positive feedback (amplifying).

Homeotherms

Animals that maintain a constant internal body temperature, such as mammals.

Ectotherms

Animals that rely on external environmental heat sources to regulate their body temperature.