Grade 11 Life Sciences Comprehensive Vocabulary

Comprehensive vocabulary flashcards covering the core terminology across Grade 11 Life Sciences strands: Diversity, Change and Continuity; Life Processes in Plants and Animals; and Environmental Studies.

Capsid

A protein coat surrounding and protecting the nucleic material ($DNA$ or $RNA$) of a virus.

Bacteriophage

A type of virus that infects and replicates within bacteria.

Binary fission

A form of asexual reproduction in single-celled organisms where a parent cell divides by mitosis into two genetically identical daughter cells.

Endospore

A tough, protective, non-reproductive bacterial structure containing $DNA$ and cytoplasm that remains dormant to survive unfavourable environmental conditions.

Plasmid

A small, circular, double-stranded $DNA$ molecule found in the cytoplasm of bacteria that is distinct from chromosomal $DNA$.

Lichen

A composite organism resulting from a mutualistic symbiotic relationship between a fungus and an alga (or cyanobacterium).

Mycorrhiza

A symbiotic association formed between fungi and the roots of higher plants that increases root surface area for nutrient absorption in exchange for sugars.

Pathogen

An infectious biological agent or organism capable of causing disease in a host.

Vector

An organism or agent that carries and transmits an infectious pathogen from an infected host into another living organism.

Phagocytosis

The process by which a cell engulfs a solid particle using pseudopodia to form an internal vesicle known as a phagosome.

Thallus

A plant body that is not differentiated into true roots, stems, or leaves and lacks a specialized vascular system.

Sori

Clusters of sporangia located on the lower surface of mature fern leaves (fronds).

Gymnosperms

A group of vascular seed-bearing plants that produce pollen and unprotected ('naked') seeds carried on cones rather than enclosed in ovaries or fruit.

Perianth

The non-reproductive outer envelope of a flower composed of the calyx (sepals) and corolla (petals) together.

Cross-pollination

The transfer of pollen grains from an anther of one flower to the receptive stigma of a flower on a different individual of the same species.

Testa

The tough, outer protective seed coat surrounding and protecting the plant embryo and stored food reserves.

Cephalisation

The evolutionary concentration of sensory organs, feeding appendages, and nervous control centers at the anterior end of an animal, forming a head.

Diploblastic

Organisms whose body walls develop from only two embryonic germ layers: the outer ectoderm and inner endoderm.

Triploblastic

Organisms that develop from three embryonic tissue layers: the ectoderm, mesoderm, and endoderm.

Coelom

A fluid-filled internal body cavity that develops entirely within the embryonic mesoderm tissue layer of triploblastic animals.

Nematocyst

A specialized stinging organelle contained within cnidocytes of cnidarians that discharges a barbed or venomous thread for defense and capturing prey.

Haemocoel

The main body cavity of invertebrates with an open circulatory system, such as arthropods, containing circulatory fluid (haemolymph).

Ecdysis

The periodic shedding or moulting of the rigid, chitinous exoskeleton in arthropods to permit growth.

Notochord

A flexible, rod-shaped skeletal support structure found in all chordate embryos, typically replaced by a vertebral column in vertebrates.

Chloroplast

A double-membraned plant cell organelle containing thylakoids, grana, and stroma, which acts as the site of photosynthesis.

Photolysis

The chemical splitting of water molecules into oxygen and hydrogen ions in the grana of chloroplasts using absorbed radiant energy during the light-dependent phase.

Phosphorylation

The biochemical synthesis of energy-rich $ATP$ molecules by joining an inorganic phosphate group to $ADP$.

Carnassial teeth

Specialized molars and premolars with sharp, jagged, triangular edges found in carnivores, adapted for shearing through meat.

Peristalsis

The automatic, rhythmic wave of circular muscle contraction and relaxation that moves food in one direction along the alimentary canal.

Chyme

The semi-liquid mass of partially digested food, enzymes, and gastric acids produced in the stomach before passing into the duodenum.

Villus

A microscopic, finger-like projection lining the inner mucosal wall of the small intestine that greatly increases surface area for nutrient absorption.

Lacteal

A central lymphatic vessel situated inside an intestinal villus that absorbs and transports digested fats (fatty acids and glycerol).

Deamination

The enzymatic removal of the amino group from excess amino acids in the liver, leading to the formation of urea.

Insulin

A pancreatic hormone that lowers blood glucose levels by promoting cellular glucose uptake and converting excess glucose into glycogen in the liver and muscles.

Glucagon

A pancreatic hormone that elevates blood glucose levels by stimulating the liver to convert stored glycogen back into glucose.

Kwashiorkor

A form of malnutrition caused by an inadequate intake of dietary protein, marked by an enlarged liver, swollen stomach, skin sores, and stunted growth.

Marasmus

A severe nutritional deficiency disorder caused by an extreme shortage of energy-rich nutrients (carbohydrates and fats), leading to muscle wasting and lack of subcutaneous fat.

Mitochondrion

A double-membraned organelle containing an internal matrix and folded cristae, functioning as the primary site of aerobic cellular respiration stages.

Glycolysis

The initial anaerobic stage of cellular respiration occurring in the cytoplasm, where glucose is split into pyruvic acid, releasing a small amount of $ATP$ and $H^+$ ions.

Anaerobic respiration

The breakdown of glucose to release energy in the absence of oxygen, producing lactic acid in animals or ethanol and carbon dioxide in plants and yeasts.

Alveoli

Microscopic, thin-walled air sacs in mammalian lungs that provide a moist, highly vascularized surface for external gaseous exchange.

Diaphragm

A dome-shaped sheet of internal muscle separating the thorax from the abdomen that contracts downward during inhalation and relaxes upward during exhalation.

Oxyhaemoglobin

The chemical compound formed when oxygen molecules bind reversibly to haemoglobin pigments inside red blood cells (erythrocytes).

Nephron

The microscopic structural and functional filtering unit of the human kidney, responsible for the formation of urine.

Malpighian body

The filtration unit in the kidney cortex consisting of the cup-shaped Bowman's capsule and the internal glomerulus capillary network.

Podocytes

Specialized epithelial cells lining the inner wall of Bowman's capsule with finger-like pedicels that create microscopic filtration slits for ultrafiltration.

Loop of Henle

The U-shaped segment of a nephron extending into the renal medulla that establishes a hypertonic osmotic gradient to recover water and concentrate urine.

Osmoregulation

The physiological control of water and salt balances in blood and bodily fluids to preserve internal homeostasis.

Aldosterone

A hormone produced by the adrenal glands that stimulates the reabsorption of sodium ions ($Na^+$) from the renal filtrate back into the blood.

Carrying capacity

The maximum population size of a biological species that a particular ecosystem can sustainably support over an indefinite period.

Environmental resistance

The combination of all limiting abiotic and biotic factors that restrict the biotic potential and numerical growth of a natural population.

Predator-prey curve

A dynamic ecological graph illustrating the cyclic fluctuations and interdependent numerical relationship between a predator population and its prey over time.

Competitive exclusion

An ecological principle stating that when two species compete directly for the exact same limited resources, one will out-compete and eliminate the other.

Resource partitioning

An evolutionary strategy where coexisting species divide resources or occupy distinct ecological niches to reduce interspecific competition.

Castes

Distinct, specialized morphological forms or functional divisions of tasks (such as reproductive, soldier, and worker groups) within social insect colonies.

Primary succession

The gradual process of ecological community development and establishment of species beginning on a newly exposed, barren substrate devoid of previous soil.

Climax community

The final, stable, and self-perpetuating biological community established at the conclusion of ecological succession.

Carbon footprint

The total amount of greenhouse gases, particularly carbon dioxide ($CO_2$), emitted directly and indirectly by human activities over a given year.

Eutrophication

The excessive nutrient enrichment of water bodies by nitrates and phosphates from runoff, triggering algal blooms that deplete dissolved oxygen upon bacterial decomposition.

Acid mine drainage (AMD)

Highly acidic, metal-rich runoff generated when underground sulfide minerals in abandoned or operating mines react with water and oxygen, polluting natural aquifers.