1. 1 Study of Biology

2. 2 What is Biology? Biology is the study of all living things Living things are called organisms Living things are called organisms All organisms share seven characteristics of life

3. 1. All organisms are made of CELLS Cells are the smallest living unit of an organism Organisms are grouped by their number of cells –Unicellular Organisms: made up of one cell –Multicellular Organisms:made up of many cells 3

4. 2. All organisms REPRODUCE to pass on their genetic traits Two Types of Reproduction: A: Sexual Reproduction: involves two organisms; an egg is fertilized by sperm; offspring DIFFERENT from parents B: Asexual Reproduction: involves a single organism (cell); cell divides in half; offspring IDENTICAL to parent 4

5. 3. All organisms have a genetic code called DNA DNA (deoxyribonucleic acid) carries the genetic code for all organisms DNA codes for the proteins that make up cells & perform cell functions perform cell functions 5

6. 4. All organisms GROW & DEVELOP Organisms grow by producing more cells & by cell enlargement Organisms develop as they mature into an adult 6

7. 5. All organisms require ENERGY The ultimate source of ALL energy is the sun. Organisms gain energy in the form of food. –Autotrophs: make their own food (energy) using the sun or chemicals –Heterotrophs: consume other organisms for food (energy) 7

8. 6. All Organisms RESPOND TO THEIR ENVIRONMENT Organisms respond to both their external and internal environment Organisms respond to temperature, water, food supplies, light, etc. in order to survive and reproduce 8

9. 9 **HOMEOSTASIS** The process of maintaining the internal environment of an organism. (Stability) If not maintained, the organism will die. Stable internal conditions of pH, temperature, water, salt, blood sugar, etc. must be maintained.

10. 7. All Organisms EVOLVE Groups Of Organisms, (not individuals) change over time in order to adapt and survive within changing environments. Fossil records show changes in groups of organisms 10

11. Organisms are grouped into Six Kingdoms 1. Bacteria: E. coli, streptococcus, stapholococcus 2. Archaea: methanogens, halophiles, thermophiles 3. Protists: seaweed, algae, amoeba 4. Fungi: mushrooms, yeast, mold 5. Plants: moss, grass, flowers 6. Animals: sponge, grasshopper, lion 11

12. What about Viruses? Viruses are NOT considered living organisms. They require a host cell in order to survive and reproduce. –While they do have some of the characteristics of life, they obtain them from their host. –Without a host, the virus will die. 12