The Biological Definition of Life Maintenance of Boundaries Movement Response to Stimuli (Environmental Δ) Taking in and Processing Nutrients Metabolism Disposal of Wastes Reproduction Growth
Maintenance of Boundaries Cell membranes control internal chemistry The Integumentary System keeps fluids in and bacteria out. It also serves to protect us from thermal and chemical damage.
Movement Get to Resources Get away from Threats Muscular System Cardiovascular System Digestive System Urinary System
Response to Stimuli (Environmental Δ) Nervous System Touching a hot burner –Moving hand away from painful stimulus
Taking in and Processing Nutrients The Digestive System At the Cellular Level
Metabolism Digestive System & Respiratory System –To make nutrients and oxygen available to the blood. Cardiovascular System –To distribute throughout the body. Endocrine System –Regulates metabolism by hormones secreted by endocrine glands.
Disposal of Wastes Respiratory System –Disposing of carbon dioxide Digestive System –Rids body of indigestible food residues Urinary System –Disposes of nitrogen- containing metabolic waste At the cellular level
Reproduction Reproductive System Endocrine System At the Cellular Level –Meiosis –Mitosis
Growth An increase in size, usually by an increase in number of cells. Onion root tip dividing
All of this requires… Nutrients Gases Water Temperature Maintenance Pressure Maintenance
Successfully doing all of this requires the maintenance of Homeostatic Balance What does Equilibrium mean in the context of a chemical system?
Control Systems
Negative Feedback Response reduces stimulus –A Thermostat –Body Temperature –Hunger
Positive Feedback Response increases stimulus –In positive feedback mechanisms, the original stimulus is promoted rather than negated. Contractions during childbirth
The Biological Definition of Life Maintenance of Boundaries Movement Response to Stimuli (Environmental Δ) Taking in and Processing Nutrients Metabolism Disposal of Wastes Reproduction Growth