1. Characteristics of Living Things

2. Key Ideas
5.2a – Homeostasis in an organism is constantly threatened. Failure to respond effectively can result in disease or death.

3. Biology Biology – Study of living things
More than 1 million different kinds of living things
All living things are similar in many ways
Organism = Living thing

4. Signs of Life
A living organism will show all of the following Signs of Life:
Highly organized and contain many complex chemical substances
Made up of one or many cells, which are the smallest unit that can be said to be alive
Living things use energy
Have definite form and limited size
Limited life span

5. Signs of Life
A living organism will show all of the following Signs of Life:
Living things grow
Respond to changes in the environment
Able to reproduce
Evolve or change, over long periods of time. This is a characteristic of groups of organisms, not of individuals

6. Non-Living Things
Non-living things may show one or a few of the Signs of Life, but they never show all of them

7. Life Processes
Introduction to the Characteristics of Life Video -

8. Life Processes
Life processes are necessary for maintaining a fairly constant environment within an organism, in spite of the constantly changing external environment
All living things must maintain homeostasis
Homeostasis – The condition of a stable (balanced) internal environment in an organism
Dynamic Equilibrium – The body stays balanced by taking action whenever the balance is disturbed

9. Life Processes
To maintain homeostasis, organisms carry out the same basic life functions:
Regulation
Transport
Nutrition
Excretion
Respiration
Growth
Synthesis
Reproduction

10. Regulation
Regulation – all of the activities that help maintain an organism’s homeostasis
Controls and Coordination of all the various activities of an organism in order to maintain homeostasis
Metabolism – all chemical reactions occurring within the cells of an organism

11. Transport
Transport – process by which substances enter and leave cells and become distributed within the cell
Transport involves both 
Absorption – process by which end products of digestion and other dissolved substances are taken into the cells and fluids of the organism
Circulation – distribution of materials within an organism
Usable materials enter the cells directly from the environment
Waste materials leave the cell and into the environment

12. Multicellular plants use structures to transport substances from roots to the leave

13. Multicellular animals use a circulatory system

14. Nutrition
Nutrition – when organisms take materials from its external environment and changes them into forms it can use
Ingestion – taking in of food
Digestion – breakdown of large, insoluble food molecules into smaller, soluble molecules that can be absorbed and used by the organism
Egestion – removal, or elimination, of undigested food materials from the organism
Nutrients – substances that an organism needs for energy, growth, repair or maintenance
Types of Nutrition:
Producers (Autotrophs) – make their own food
Consumers (heterotrophs) – cannot make their own nutrients so they obtain ready made nutrients by eating other organisms

15. Nutrition Types of Nutrition:
Producers (Autotrophs) – make their own food
Consumers (heterotrophs) – cannot make their own nutrients so they obtain ready made nutrients by eating other organisms
Ingestion – taking in of food from the environment
Digestion – breakdown of complex food materials into simpler forms that an organism can use

16. Excretion
Excretion – removal from the organism of waste substances produced in the cells as a result of their life activities
Organisms produce wastes substances that cannot use and that may be harmful if accumulated in the body
Waste are products of many chemical reactions that occur in cells

17. Respiration
Respiration – process by which energy is obtained from the breakdown of food and stored in a form that can be used to carry on life activities
Creation of energy!!!!
ATP is the energy source of all living things
Types of Respiration:
Aerobic Respiration – breakdown of sugar into carbon dioxide and water that requires oxygen and yields more ATP for a molecule of glucose
Anaerobic Respiration – breakdown of sugar into carbon dioxide and water without oxygen and yields less ATP for a molecule of glucose

18. Growth Growth – increase in size and/or number of cells of an organism
Organisms can repair and replace worn-out parts
Cellular Specialization – process that involves different cells becoming specialized for different functions

20. Synthesis
Synthesis – all the chemical reactions by which large molecules are produced from smaller molecules within the organism
Examples:
Photosynthesis – process by which energy from light in converted into chemical energy in the presence of chlorophyll
Formula : 6 CO2 + 6 H2O  C6H12O6 + 6 O2
Protein Synthesis - formation of protein molecules (chain of amino acids) that occurs at cell’s ribosome
Formula : Amino Acids (Small)  Protein (Large)

21. Reproduction Reproduction – production of new individuals
Is not necessary for the life of a single organism but is necessary for the continued existence of a particular species of organism
Types of Reproduction:
Asexual – single individual produces an identical offspring
Sexual – two parents and the offspring is not identical to either parent