NSSCO Biology Grade 10-11 Comprehensive Vocabulary

Essential vocabulary flashcards covering the NSSCO Grade 10-11 Biology curriculum, including scientific processes, classification, cell physiology, plant and human systems, inheritance, and ecology.

Independent Variable

The condition or factor that is changed on purpose (manipulated) in a scientific investigation.

Dependent Variable

The variable that is measured in an experiment, representing the changes observed due to manipulations of the independent variable.

Hypothesis

An educated guess concerning the outcome of an investigation that states the expected relationship between the dependent and independent variables.

Binomial System

A system of naming species of living things in which the scientific name consists of two parts in Latin: the genus name (capitalized) followed by the species name (lowercase).

Human Immunodeficiency Virus (HIV)

A non-cellular pathogen composed of a protein capsid enclosing two identical strands of RNA genetic material and reverse transcriptase enzymes, surrounded by an outer viral envelope embedded with glycoproteins.

Monocotyledons

A class of flowering plants characterized by seeds containing one cotyledon, leaves with parallel veins, floral parts in multiples of 3, and fibrous root systems.

Dicotyledons

A class of flowering plants characterized by seeds containing two cotyledons, leaves with branching networks of veins, floral parts in multiples of 2 or 5, and a taproot system.

Radula

A rasping, tongue-like organ found in molluscs that is used for scraping pieces of food off surfaces.

Cephalothorax

A fused body section comprising the head and thorax, found in arachnids and crustaceans.

Magnification

A measure of how much larger an image is compared to the actual size of the specimen, calculated as $\text{Magnification} = \frac{\text{size of drawing}}{\text{actual size of object}}$.

Organelle

A tiny cellular structure enclosed within a membrane that performs a specific metabolic function within a cell.

Diffusion

The net movement of molecules, atoms, or ions from a region of higher concentration to a region of lower concentration down a concentration gradient as a result of their random kinetic movement.

Osmosis

The net movement of water molecules from a region of higher water potential to a region of lower water potential through a partially permeable membrane down a water potential gradient.

Active Transport

The movement of particles (ions or molecules) through a cell membrane from a region of lower concentration to a region of higher concentration against a concentration gradient, using energy released from respiration.

Catalyst

A substance that increases the rate of a chemical reaction without being chemically altered or consumed by the reaction.

Active Site

The specific region or cleft on an enzyme molecule that possesses a complementary shape into which the substrate fits to undergo a chemical reaction.

Autotrophic Nutrition

A mode of nutrition where organisms synthesize organic food molecules from inorganic raw materials ($\text{CO}_2$ and water) using chlorophyll and light energy during photosynthesis.

Heterotrophic Nutrition

A mode of nutrition where organisms obtain and ingest ready-made organic molecules from other organisms as their source of energy and matter.

Limiting Factor

An environmental factor that is in shortest supply and restricts the rate of a physiological process such as photosynthesis.

Balanced Diet

A diet containing all seven essential nutrient groups in the correct proportions and quantities required for growth, tissue repair, and health maintenance.

Ingestion

The process of taking food substances into the body through the mouth.

Chemical Digestion

The enzymatic breakdown of large, complex, insoluble food molecules into small, soluble molecules that can be absorbed across the intestinal wall.

Emulsification

The mechanical breakdown of large fat globules into numerous tiny fat droplets by bile salts, increasing the total surface area for lipase enzymes to act on.

Intestinal Villus

A microscopic, finger-like projection of the ileum wall lined with a single layer of epithelial cells containing micro-villi, capillaries, and a central lacteal to maximize nutrient absorption.

Transpiration

The loss of water vapour from plant leaves caused by the evaporation of water from the surfaces of mesophyll cells followed by diffusion out through open stomata.

Xerophytes

Plants adapted to survive in arid environments with limited water availability through adaptations such as succulent water-storing tissues, reduced leaf surface area, and sunken stomata.

Translocation

The transport of soluble organic products of photosynthesis (sucrose and amino acids) through the phloem sieve tubes from regions of supply or storage to regions of utilization or growth.

Double Circulation

A circulatory system where blood passes through the heart twice during a single complete journey around the body, consisting of pulmonary and systemic circuits.

Pathogen

A disease-causing biological organism, such as a bacterium, virus, fungus, or protozoan.

Phagocytosis

The cellular defence mechanism where a phagocytic white blood cell (such as a neutrophil) detects, engulfs, and digests a foreign pathogen using enzymes stored in lysosomes.

Active Immunity

Long-term immunity acquired through antibody production by the individual's own lymphocytes, resulting in the generation of memory cells following infection or vaccination.

Passive Immunity

Short-term defence against a pathogen conferred by receiving ready-made antibodies from another individual (e.g., via breast milk or antiserum) without producing memory cells.

Aerobic Respiration

The chemical breakdown of nutrient molecules in cells in the presence of oxygen to release large amounts of energy ($\text{C}_6\text{H}_{12}\text{O}_6 + 6\text{O}_2 \rightarrow 6\text{CO}_2 + 6\text{H}_2\text{O}$).

Anaerobic Respiration

The chemical reactions in cells that break down nutrient molecules to release a relatively small amount of energy in the absence of oxygen.

Deamination

The enzymatic removal of the nitrogen-containing amino group from excess amino acids in the liver to produce ammonia, which is rapidly converted into urea.

Homeostasis

The maintenance of a constant internal environment within an organism, including constant body temperature, water balance, and blood glucose concentration.

Negative Feedback

A regulatory mechanism where a change in a physiological parameter triggers corrective responses by effectors to return the parameter back toward its normal set point.

Pupil Reflex

An involuntary reflex that adjusts the diameter of the pupil in response to changing light intensity through the antagonistic action of circular and radial iris muscles.

Mitosis

Nuclear division that gives rise to two genetically identical daughter nuclei, each maintaining the diploid chromosome number of the parent cell.

Meiosis

A reduction cell division in which the chromosome number is halved from diploid to haploid, producing four genetically diverse gametes through crossing over and independent assortment.

Gene

A specific length of DNA situated on a chromosome that codes for the synthesis of a specific protein.

Allele

One of two or more alternative versions of the same gene located at the same locus on homologous chromosomes.

Co-dominance

A genetic condition where two different alleles of a gene are both expressed in the phenotype of a heterozygous individual without blending.

Natural Selection

The process whereby organisms with inherited adaptive traits suited to their environment have greater reproductive success and pass those traits to offspring.

Producer

An autotrophic organism that synthesizes organic nutrients from sunlight and inorganic substances, occupying the first trophic level in an ecosystem.

Food Web

A complex network of interconnected food chains that illustrates the multiple feeding interactions and energy pathways among organisms within an ecosystem.

Pyramid of Biomass

An ecological pyramid showing the total dry mass of biological material present at each successive trophic level in a food chain at a given time.

Carbon Cycle

The biogeochemical cycle through which carbon flows between the atmosphere, living organisms, soil, and fossil reserves via photosynthesis, respiration, feeding, decomposition, and combustion.

Sigmoid Growth Curve

An S-shaped population growth pattern characterized by a lag phase, exponential (log) growth phase, and a stationary phase where the population stabilizes at the environmental carrying capacity ($K$).

Eutrophication

An environmental disruption caused by the leaching of excess nitrates and phosphates into water bodies, leading to rapid algal blooms, underwater plant death, and severe oxygen depletion by aerobic decomposing bacteria.

Sustainable Development

Development that provides for the resource requirements of an increasing human population while preserving environmental health and natural resources for future generations.