Define Respiration.
A chemical reaction that happens in most cells inthe body. Oxygen and glucose is used to release energy. Summarised as-
O2 + Glucose → CO2 +H2O + Energy
Define Evolution.
The gradual change in characteristics of a population over many generations driven by natural selection.
Define Natural Selection. (survival of the fittest)
Environmental pressures (such as food availability, predation, and reproduction) enable only the best suited individuals in a population to survive and reproduce successfully. They then pass their characteristics onto their offspring.
Define Covergent Evolution.
Animals evolving similar characteristics whilst not neccessarily sharing a common ancestor. (Bats & Birds)
Define Divergent Evolution.
Animals evolving drastically different characteristics whilst sharing a common ancestor. (Whales, Bats, Giraffe)
Define Diffusion.
Random movement of particles (gas or liquid) from an area of high concentration to an area of low concentration.
Define Osmosis.
Random movement of water molecules through a partially permeable membrane from high concentration to low concentration.
Define Partially Permeable.
Will allow smaller substances to pass through but not larger ones.
Define Concentration Gradient.
The difference in the concentration of a substance from one area to another. The bigger the difference in concentration, the larger the concentration gradient.
Define Active Transport.
When energy is used to transport substances against a concentration gradient (ie: from low to high concentration).
Define Solute.
A substance that will dissolve in a liquid. (e.g. salt)
Define Solvent.
A liquid that a solute dissolves in. (e.g. water)
Define Solution.
A mixture of a dissolved solute & solvent. (e.g. salt water)
Define Enzymes.
Biological catalysts which speed up reactions in the body without being directly involved in the reaction themselves. They are involved in reactions such as digestion and respiration.
Define Homeostasis.
The regulation of the internal conditions of the body. Including factors such as body temperature, blood PH, and blood pressure. Homeostasis maintains stability.
Define Feedback Mechanism.
A physiological regulation system in a living body that works to return the body to its normal internal state (homeostasis). Can be either positive or negative.
Define Positive Feedback Loop.
Positive feedback is described as when the effect is increased or stimulated (e.g. oxytocin causes contractions of the uterus, contractions then stimulate more oxytocin to be produced).
Define Negative Feedback Loop.
Negative feedback is where the effect is inhibited or slowed down (e.g. insulin is released to lower glucose levels. When glucose returns to a safe level, insulin is no longer released).
Define Thermoregulation.
The ability of an organism to regulate its body temperature, regardless of the external temperature.
Define Endocytosis.
The process of transporting substances into a cell. The cell membrane surrounds the substance and then forms a vesicle.
Define Exocytosis.
The process by which substances are removed from a cell. Vesicles fuse with the cell membrane and then substances are released.
Define Isotonic.
When the concentration of solute is equal inside & outside the cell.
List Functions of the Skeletal System.
Protection, locomotion, attachment of the skeletal muscle, production and storage of blood cells, and storage of minerals.