Year 7 Cells and Classification AT3 Prep Science MHS

A vocabulary set covering key terms from the 7.3 Cells and Classification notes, including living things, classification, taxonomy, cell theory, organelles, energy processes, and Indigenous classification concepts.

Living things

Organisms that display Characteristics of Life and can be distinguished from non-living things.

Characteristics of Life

The shared processes that define life: Movement, Responses to Stimuli, Respiration, Assimilation, Growth, Reproduction, Excretion.

Movement

The ability of living things to move or change position, either visibly (animals) or less obviously (plants).

Responses to Stimuli

Detecting and responding to changes in the surroundings.

Respiration

Producing energy through chemical processes to supply the organism.

Assimilation

Absorption of nutrients to support growth and repair of the body.

Growth

Increase in body mass by cell multiplication.

Reproduction

Production of offspring by sexual or asexual processes.

Excretion

Removal of waste materials produced during metabolism.

Classification

The process of grouping similar things together based on common features.

Taxonomy

The science of identifying, describing, naming, and classifying organisms into hierarchical groups.

Binomial nomenclature

Scientific naming of species using genus and species names (genus capitalised; species lowercase; Italicised or underlined).

Linnaean system

The internationally recognised taxonomic system based on binomial nomenclature and hierarchical classification.

Five Kingdom Classification System

Early framework dividing life into Monera, Protista, Fungi, Plantae, and Animalia (later expanded by domains).

Prokaryote

Organism lacking a defined nucleus and membrane-bound organelles (e.g., bacteria, archaea).

Eukaryote

Cell or organism with a defined nucleus and membrane-bound organelles (multicellular or unicellular).

Kingdoms (Monera, Protista, Fungi, Plantae, Animalia)

Initial Linnaean grouping of life into five kingdoms before domains were added.

Domain

A higher taxonomic rank above kingdoms (Archaea, Bacteria, Eukarya).

Species

A group of organisms with the same evolutionary history, capable of interbreeding to produce viable offspring; share chromosome number and genetic similarities.

Subspecies

A distinct population within a species with characteristic differences, but not enough to be a separate species.

Hybrids

Offspring resulting from the cross-breeding of two different or closely related species; often sterile (exceptions exist).

Dichotomous key

A tool that uses paired statements to identify organisms by progressively narrowing options.

Adaptations

Ways organisms cope with environmental stresses to survive: structural, behavioural, and physiological.

Structural adaptation

Physical features of an organism (e.g., body parts, coloration) that aid survival.

Behavioural adaptation

Actions or behaviors that help an organism survive in its environment.

Physiological adaptation

Internal bodily processes that enhance survival (e.g., venom production, temperature regulation).

Cell

The basic unit of life; all living things are composed of one or more cells.

Tissue

A group of similar cells that work together to perform a specific function.

Organ

A structure made of two or more tissues that carries out a specific function.

System

A group of organs that work together to perform a broader task in the organism.

Organelles

Specialised structures within a cell that perform specific functions (e.g., nucleus, mitochondria).

Cell membrane

Thin, tough boundary that surrounds the cell; controls movement of substances in and out.

Cytoplasm

The cell contents outside the nucleus; site of many chemical reactions; contained in cytosol.

Nucleus

Control centre storing genetic material and coordinating cellular activities.

Mitochondria

Powerhouse of the cell; site of cellular respiration producing ATP.

Chloroplasts

Organelles in plants where photosynthesis occurs; contain chlorophyll.

Vacuole

Storage and waste disposal organelle; largest in plant cells.

Cell wall

Rigid layer outside the cell membrane in plants; made of cellulose; provides support.

Endoplasmic reticulum

Network of membranes; rough has ribosomes (protein synthesis); smooth lacks ribosomes (lipid synthesis and transport).

Golgi apparatus

Modifies, sorts, and packages substances for transport within or outside the cell.

Ribosome

Site of protein synthesis; can be free-floating or attached to ER.

Plant cell

Cell type characterized by cell wall, vacuole, and chloroplasts in addition to standard organelles.

Animal cell

Cell type lacking cell wall and chloroplasts; typically contains nucleus, membrane, cytoplasm, mitochondria.

Photosynthesis

Process by which green plants convert sunlight into glucose in chloroplasts.

Chlorophyll

Green pigment in chloroplasts that absorbs light for photosynthesis.

Cellular respiration

Process that releases energy (ATP) by breaking down glucose, mainly in mitochondria.

ATP

Adenosine triphosphate; the energy currency produced by cellular respiration.

Cristae

Folded inner membranes of mitochondria where ATP production occurs.

Indigenous classification systems

Diverse binary and hierarchical ways First Nations Australians classify plants and animals based on uses, forms, and functions (e.g., edible/non-edible; totemic/non-totemic).