Essential Standard Bio.1.2 Analyze the cell as a living system Biology Essential Standard Bio.1.2 Analyze the cell as a living system

Biology Organism - living thing Biology - study of all living things Structure and function of cells Interactions between species History of individual organisms

Characteristics of Life Characteristics of Life = all organisms share certain features characteristic of all living things 6 characteristics!

1. Contains Cells Cell - basic unit of life Unicellular organisms - composed of one cell (identical copies) Multicellular organisms – composed of more than one cell through differentiation Differentiation – process where cells become different for different tasks Skin Cells Bacteria

2. Shows Levels of Organization Living things are organized at molecular and cellular levels Simple to Complex In Organisms: Atom  Molecule  Organelle  Cell  Tissue  Organ  Organ system Organism In Ecosystem: Organism Population  Community  Ecosystem  Biosphere

3. Energy Use Living things use energy (metabolism) Energy used for maintenance, growth, and reproduction Autotrophs = make own energy through photosynthesis Heterotrophs = consumes energy

4. Maintains Homeostasis Homeostasis - maintaining stable internal conditions Internal conditions (e.g. food, water, and temperature) are controlled within the organism

5. Growth All living things grow as a result of cell division and cell enlargement Organism development is produced by repeated cell divisions and cell differentiation

6. Reproduces Reproduction – organisms produce new organisms DNA is passed to offspring Gene – short segment of DNA containing a single trait Asexual Reproduction – identical copy of parent cell Sexual Reproduction – combination of gametes (sperm + egg)

Populations Evolve Populations of organisms evolve in response to environmental factors Natural Selection – organisms with favorable traits reproduce