Grade 9 Science and Technology Vocabulary Flashcards

Vocabulary flashcards defining core terms and key concepts across scientific method, biology, mushroom anatomy, evolution, mechanics, simple machines, atomic structure, chemical reactions, and atmospheric gases from Grade 9 Science and Technology.

Scientific Process Skills

The foundational abilities required for scientific learning, including observation, questioning, classification, prediction, interpretation, measurement, concluding, and communication.

Science

An organized method and knowledge-building process used to discuss natural events on the basis of fact.

Biology

The field of science that studies living organisms, including their properties, reproduction, excretion, respiration, behavior, body structure, and interactions with the environment.

Physics

The field of science that studies physical phenomena such as force, motion, and energy across scales from the atom to the universe.

Chemistry

The field of science that studies matter, its properties based on atoms and molecules, and how those properties change during chemical reactions.

Water Bath

A safety technique used to heat volatile or flammable liquids, such as alcohol, by placing the sample container inside a vessel filled with hot water.

Least Count

The smallest or lowest quantity that can be accurately measured by a specific measuring instrument.

Classification of Living Beings

The process of categorizing living organisms into groups and subgroups based on their similar and dissimilar characteristics.

Binomial System of Nomenclature

The system devised by Carolus Linnaeus for naming organisms using two Latin words: the generic name (Genus) and the specific name (Species).

Genus

A taxonomic rank comprising a group of species with maximum similar characteristics, positioned below family and above species.

Species

The smallest fundamental unit of taxonomy, consisting of similar organisms capable of interbreeding with one another.

Mycelium

The underground vegetative structure of a fungus or mushroom, composed of fine thread-like fibers called hyphae.

Hyphae

Fine thread-like filaments that make up the mycelium of a mushroom or fungus.

Stipe

The stem or stalk-like structure supporting the cap of a mushroom.

Pileus

The upper umbrella-like cap structure of a mushroom's fruiting body.

Gills

The lamellated structures situated beneath the pileus of a mature mushroom that bear basidiospores.

Lichens

A symbiotic association between algae and fungi, wherein fungi provide habitat and water while algae produce carbohydrates.

Evolution

The process of gradual structural modification in living organisms over time, progressing from simple forms to complex organisms and forming new species.

Fossil

The preserved traces, remnants, or imprints of ancient plants and animals preserved in sedimentary rock layers.

Homologous Organs

Organs in different organisms that share the same embryonic origin and anatomical structure but serve different functions, such as human hands and horse forelegs.

Analogous Organs

Organs in different organisms that perform similar functions but possess distinct embryonic origins and internal structures, such as insect wings and bird wings.

Vestigial Organs

Rudimentary or non-functional organs in living organisms that were fully developed and functional in their evolutionary ancestors.

Connecting Links

Organisms that exhibit morphological or anatomical traits belonging to two distinct taxonomic groups, such as the duck-billed Platypus.

Somatogenic Variation

Non-inheritable changes acquired in bodily tissues during an organism's life due to environmental factors, which disappear upon the organism's death.

Blastogenic Variation

Heritable variations caused by changes in germ cells or genetic material that are transmitted to future generations.

Mutation

A sudden and discontinuous chromosomal or genetic change in an organism that produces novel characteristics in offspring.

Displacement

The shortest linear distance measured from an object's initial position to its final position in a specified direction, represented as a vector quantity.

Velocity

The rate of displacement of an object per unit time in a specified direction.

Acceleration

The rate of change in velocity per unit time, expressed in units of $\text{m/s}^2$.

Retardation

The rate of decrease in velocity per unit time, also known as negative acceleration.

Inertia

The inherent property of a body to resist any change in its existing state of rest or uniform motion in a straight line.

Inertia of Rest

The tendency of a body at rest to resist motion and remain at rest unless acted upon by an unbalanced external force.

Inertia of Motion

The tendency of a moving body to maintain its state of uniform motion at constant speed unless acted upon by an external force.

Deforming Force

An applied resultant force that alters the physical shape, size, or structural dimensions of an object.

Elasticity

The property of matter by which a deformed body regains its original shape and size upon removal of the deforming force.

Plasticity

The property of matter by which a body maintains its deformed shape and size even after the removal of the deforming force.

Mechanical Advantage (MA)

The dimensionless ratio of the load lifted by a simple machine to the effort force applied ($\text{MA} = \frac{\text{Load}}{\text{Effort}}$).

Velocity Ratio (VR)

The dimensionless ratio of the distance moved by the effort force to the distance moved by the load ($\text{VR} = \frac{\text{Effort Distance}}{\text{Load Distance}}$).

Wedge

A simple machine featuring a broad flat surface at one end and a sharp edge created by two intersecting inclined planes.

Pitch

The distance between two consecutive threads on a screw.

Efficiency

The percentage ratio of useful output work done by a machine to the input work performed on it ($\text{Efficiency} = \frac{\text{Output Work}}{\text{Input Work}} \times 100\%$).

Perfect Machine

An ideal, frictionless machine with $100\%$ efficiency, wherein output work equals input work.

Atom

The smallest unit particle of an element that retains its identity and can participate in chemical reactions.

Duplet Rule

The principle wherein an atom attains chemical stability by securing $2$ electrons in its innermost $K$-shell.

Octet Rule

The principle wherein an atom achieves chemical stability by attaining $8$ electrons in its outermost valence shell.

Valence Shell

The outermost electron shell of an atom containing electrons that participate in chemical bonding.

Valency

The combining capacity of an atom, determined by the number of valence electrons lost, gained, or shared during chemical combination.

Cation

A positively charged ion formed when a neutral atom loses one or more valence electrons.

Anion

A negatively charged ion formed when a neutral atom gains one or more electrons into its valence shell.

Electrovalent Bond

A chemical bond formed by the complete transfer of one or more valence electrons from a metal atom to a non-metal atom.

Covalent Bond

A chemical bond formed by the mutual sharing of equal pairs of electrons between non-metallic atoms.

Nuclear Fission

A nuclear reaction in which a heavy, unstable atomic nucleus breaks into smaller nuclei upon bombardment by high-speed neutrons, releasing energy.

Nuclear Fusion

A nuclear reaction wherein light atomic nuclei combine under extreme temperature and pressure to produce a heavier nucleus and release energy.

Exothermic Reaction

A chemical reaction that releases thermal energy into its surrounding environment.

Endothermic Reaction

A chemical reaction that absorbs thermal energy from its surrounding environment.

Isotopes

Atoms of the same chemical element that possess identical atomic numbers but different mass numbers, such as $^1\text{H}^1$, $^1\text{H}^2$, and $^1\text{H}^3$.

Ozone Layer

A region within the stratosphere, situated $25\,\text{km}$ to $40\,\text{km}$ above Earth's surface, that absorbs harmful solar ultraviolet radiation.