Characteristics & Classification of Living Organisms; Organisation of the Organism

Vocabulary flashcards covering key terms from Chapters 1–2, including characteristics of life, classification, cell structures, specialised cells, biological hierarchy, and magnification concepts.

Movement

An action by an organism causing a change of position or place.

Respiration

Chemical reactions in cells that break down nutrients to release energy.

Sensitivity

The ability to detect stimuli and respond appropriately.

Growth

A permanent increase in size and dry mass due to cell number or size increase.

Reproduction

The process of producing more individuals of the same kind of organism.

Excretion

Removal of toxic materials and the waste products of metabolism from the body.

Nutrition

Intake of materials (food, minerals) for energy, growth, and development.

Species

A group of organisms capable of interbreeding to produce fertile offspring.

Binomial system

Two-part scientific naming of organisms consisting of genus and species names.

Purpose of classification

Grouping organisms by shared features and reflecting their evolutionary relationships.

Five kingdoms

The major groups: Animal, Plant, Fungus, Prokaryote (bacteria), and Protoctist.

Vertebrates

Animals with backbones, including mammals, birds, reptiles, amphibians, and fish.

Arthropods

Invertebrates with exoskeletons and jointed legs: insects, arachnids, crustaceans, myriapods.

Flowering plants

Monocot or dicot plants that reproduce via flowers and seeds; contrast with ferns.

Viruses

Non-cellular particles consisting of a protein coat surrounding genetic material.

Dichotomous key

A tool that identifies organisms through a series of paired, contrasting statements.

Plant cell

Eukaryotic cell with cell wall, chloroplasts, permanent vacuole, and typically a fixed shape.

Animal cell

Eukaryotic cell lacking a cell wall and chloroplasts, usually with an irregular shape.

Bacterial cell

Prokaryotic cell with cell wall, membrane, cytoplasm, ribosomes, circular DNA, and plasmids but no nucleus.

Nucleus

Organelle that controls cell activities and contains genetic material.

Cytoplasm

Jelly-like substance where most chemical reactions occur.

Cell membrane

Partially permeable barrier controlling movement of substances into and out of the cell.

Mitochondria

Organelles where aerobic respiration and energy release occur.

Ribosomes

Tiny structures in the cytoplasm where proteins are synthesised.

Chloroplasts

Organelles containing chlorophyll for photosynthesis in plant cells.

Permanent vacuole

Fluid-filled space in plant cells for storage and maintenance of turgor pressure.

Cell wall

Rigid structure of cellulose in plants providing support and protection.

Ciliated cell

Specialised cell with hair-like cilia that move mucus in the respiratory tract.

Root hair cell

Plant epidermal cell with a long extension to absorb water and minerals from soil.

Palisade mesophyll cell

Tall, chloroplast-rich leaf cell specialised for photosynthesis.

Neurone

Nerve cell specialised to conduct electrical impulses rapidly.

Red blood cell

Biconcave cell containing haemoglobin for oxygen transport.

Sperm cell

Male gamete specialised for motility and delivering genetic material to the egg.

Egg cell (ovum)

Large female gamete containing nutrients and genetic material for embryonic development.

Cell (level of organisation)

Basic structural and functional unit of life.

Tissue

Group of similar cells working together to perform a specific function.

Organ

Structure made of different tissues working together to carry out a particular job.

Organ system

Group of organs that work together to perform major body functions.

Organism

An individual living entity capable of carrying out all life processes.

Magnification formula

Magnification = image size ÷ actual size.

Millimetre–micrometre conversion

1 mm = 1000 μm; used when calculating magnification and specimen size.