AP Biology - Introduction

Four Big Ideas 1. The process of evolution drives the diversity and unity of life. 2. Biological systems utilize free energy and molecular building blocks to grow, to reproduce and to maintain dynamic homeostasis. 3. Living systems store, retrieve, transmit and respond to information essential to life processes. 4. Biological systems interact, and these systems and their interactions possess complex properties.

Shared Characteristics of Life Organic compounds- carbohydrates, lipids, nucleic acids, proteins Universal genetic code Made of cells or a cell Maintenance of homeostasis- constant internal environment Reproduction due to limited life spans Evolve due to environmental and biological pressures.

Basic Understood Information 1. Earth formed between 4.5 and 4.6 billion years ago. 2. 600 million years later life formed. 3. Prokaryotes (single-cell organisms with no nucleus) dominated Earth for 2 billion years in the oceans. There was no O2 or O3.

4. Autotrophs are organisms that make chemical energy through photosynthesis or chemosynthesis. Heterotrophs are organisms that consume other organisms for food or break them down through decomposition. 5. Organisms metabolize energy through either aerobic or anaerobic respiration or both.

6. Organisms made of eukaryotic cell(s) (which have a nucleus and other membrane-bound organelles) are animals, plants, fungi, and protists. 7. The Theory of Endosymbiosis serves as evidence for the evolution of eukaryotes. 8. Multicellular organisms arose about 1 billion years ago.

9. Mutations in DNA allow organisms to change or evolve. 10. Organisms are classified based on their DNA reflecting common ancestry.