Characteristics of Life

Study of Biology The study of all living things Living things are called organisms Bacteria, protists, fungi, plants, & animals

All Organisms Share Common Characteristics Cellular Organization Homeostasis Metabolism Respond to stimuli Reproduce Heredity (DNA) Growth

Cellular Organization Cells are the smallest living unit of an organism Cells have parts called organelles that do different jobs All cells are surrounded by a cell membrane that controls what enters & leaves the cell Same basic structure in all organisms

Organisms are Grouped by their Number of Cells Unicellular Organisms Living Organism Made Up Of One Cell Multicellular Organisms Living Organism Made Up Of Many, Specialized Cells

Homeostasis Keeping the internal environment of the Cell or organism within the ranges required for life Stable internal conditions of pH, temperature, water balance, etc.

Metabolism The sum of all chemical reactions carried out by an organism Sunlight is the source of energy for plants - photosynthesis Plants serve as the source of energy for other organisms – cellular respiration

Response Organisms respond to their external environment Stimuli like Temperature, Water, Food Supplies, etc. Plants bend toward sunlight, a bird fluffs feathers for warmth

Reproduction Sexual Reproduction Asexual reproduction Involves 2 parents Offspring DIFFERENT from parents Asexual reproduction Only 1 parent Offspring identical to parent

Heredity All cells contain DNA (deoxyribose nucleic acid) carries the genetic code for all organisms DNA codes for the proteins that make up cells & do all the work The DNA molecule is the same in ALL organisms

Growth All Organisms grow and develop Organisms grow by producing more cells & by cell enlargement Organisms develop as they mature into an adult organism

Where Life Begins