G.C.E. A/L Biology - Plant Physiology, Animal Tissues, Nutrition, and Circulation

Vocabulary flashcards covering plant environmental stress responses, human histology, digestive enzymes, vitamins, arthropod circulation, and human cardiac anatomy based on Grade 13 Biology exam questions.

Drought Stress Response in Plants

A physiological response in plants characterized by the release of abscisic acid ($\text{ABA}$) to regulate transpiration and reduce water loss.

Biotic Stress Response in Plants

A plant defense mechanism involving the synthesis of secondary metabolites, such as phenolic compounds, to resist biological attackers.

Cold Stress Response in Plants

A protective adaptation where plant cells increase their intracellular solute concentration to prevent intracellular ice formation and chilling injury.

Salt Stress Response in Plants

A mechanism of osmotic and ionic regulation in which halophytic or tolerant plants actively secrete excess accumulated salts out of their tissues.

Haversian System (Osteon)

The repeating microscopic structural and functional unit characteristic of compact bone tissue in the human body.

Pepsin

An active gastric endopeptidase enzyme secreted by the stomach that uses dietary protein as its substrate.

Pancreas

An accessory digestive gland located nestled inside the C-shaped loop of the duodenum.

Vitamin C

A water-soluble micronutrient and antioxidant that is directly required for the enzymatic synthesis of collagen fibers.

Arthropod Open Circulation

A circulatory pattern in which the circulating fluid directly bathes tissues, allowing direct chemical exchange to occur between the fluid and body cells.

Atrioventricular (AV) Node

A node of specialized cardiac electrical conducting tissue situated within the septum between the right and left atria.