Chapter Two

• Living thing


  Anything that can move, respire, sense, grow, reproduce, maintain equilibrium, excrete waste, and take up nutrients
• Homeostasis


  The maintenance of a relatively stable internal environment in the body despite changes in the external environment
• Organism


  A living thing made up of one or more cells
• Cell theory


  The idea that all living things are made of cells, cells are the smallest functional unit of living things, and all cells come from pre-existing cells
• Prokaryotes


  A group of single-celled organisms with no nucleus and a circular loop of DNA
• Eukaryotes


  A group of single and multi-celled organisms with a nucleus and linear strands of DNA
• Plasma membrane


  The phospholipid bilayer and embedded proteins which separate the intracellular environment from the extracellular environment
• Cytosol


  The aqueous fluid that surrounds the organelles inside a cell
• Ribosomes


  Small RNA-protein structures that are the site of protein synthesis
• DNA


  A double-stranded nucleic acid chain made up of nucleotides that carries the instructions for proteins
• Membrane-bound organelle


  Structure within a cell that is enclosed by a phospholipid bilayer
• Chromosome


  The structure made of protein and nucleic acids that carries genetic information
• Nucleus


  A double membrane-bound organelle that protects and confines the genetic information of a cell
• Plasmid


  A small, circular loop of DNA that is separate from a chromosome
• Somatic cell


  Any cell that is not a reproductive cell
• Mitosis


  The cell division phase which involves the complete separation of sister chromatids and nuclei
• Germline cells


  Cells that are involved in the generation of gametes in eukaryotes
• Gametes


  Reproductive cells that arise from germline cells
• Meiosis


  A specialised form of cell division used to produce gametes in sexually-reproducing organisms
• Binary fission


  The method of cell replication used by prokaryotes
• Micrometres (μm) is a unit of measurement where 1 mm = 1000μm
• Organelle


  A cellular structure that performs specific functions
• Cytoplasm


  The cytosol and organelles inside the plasma membrane, excluding the nucleus
• Ribosomal RNA (rRNA)


  A type of nucleic acid that is a key structural component of ribosomes
• Lumen


  The space within a cavity which can act as a passage-way
• Mitochondrion


  The primary site of energy production from aerobic cellular respiration
• Cellular respiration


  The biochemical process in all living things that converts glucose into ATP
• Matrix


  The space inside the inner membrane of the mitochondria
• Crista


  The fold of the inner membrane of the mitochondria
• Aerobic


  Requiring oxygen
• Anaerobic


  Requiring no oxygen
• Chloroplast


  A double membrane-bound organelle that contains flattened, fluid-filled sacs that are the site of photosynthesis
• Algae


  A large diverse group of photosynthetic protists found in aquatic environments
• Granum


  A stack of thylakoids
• Thylakoid


  A flattened sac-like structure inside the chloroplast
• Stroma


  The fluid substance that makes up the interior of chloroplasts
• Photosynthesis


  The process of converting light energy, carbon dioxide, and water into glucose and oxygen
• Chlorophyll


  A green pigment found in the thylakoids of chloroplasts
• Endosymbiosis


  When one organism lives inside another in a mutually beneficial relationship
• Endosymbiosis theory


  A theory suggesting that chloroplasts and mitochondria were once free-living organisms