Chapter 19: Origin and History of Life

1. Chapter 19: Origin and History of Life

2. Chemical evolution is the increase in complexity of chemicals leading to the first cells         1. While today life only comes from life, the first cells had to arise from an increased complexity of chemicals.

3. B. The Atmosphere Forms         3. Primitive atmosphere was formed by volcanic out-gassing characteristic of the young earth.

4. C. Monomers Evolve • 3. AleksandrOparin'sHypothesis • Suggested organic molecules could be formed in the presence of outside energy sources: • 1) methane (CH4) • 2) ammonia (NH3) • 3) hydrogen (H2 • 4) water (H2O)

5. D. Polymers Evolve         1. Newly formed organic molecules polymerized to produce larger molecules and macromolecules.

6. E. A Protocell Evolves         1. Before the first cell arose, there would have been a protocell.   2. A protocell would have with a lipid-protein membrane and carry on energy metabolism.

7.         4. Oparin demonstrated a protocell could have developed from coacervate droplets. .

8. F. A Self-Replication System Evolves         1. In living systems, information flows from DNA  RNA  protein; this sequence developed in stages.

9. 19.2. History of Life

10. A. Macroevolution is the large scale pattern of change taking place over very long time spans

11. B. Fossils Tell a Story         1. A fossil is the remains or traces of an organism preserved in sediment or rock.

12.         2. Eukaryotic Cells Arise a. The eukaryotic cell of 1.5 billion years ago is aerobic and contains a nucleus and organelles. b. Theory of endosymbiosis: nucleated cells engulfed prokaryotes that became various organelles.

13.   3. Multicellularity Arises a. It is not known exactly when multicellular organisms appeared. b. Separating germ cells from somatic cells may have contributed to diversity of organisms.

14. 19.3. Factors That Influence Evolution

15. Continental drift explains why the coastlines of several continents A. Continental Drift

16. Chapter 20: Classification of Living Things

17. 20.1. Taxonomy

18. A. Taxonomy is the branch of biology concerned with identifying and naming organisms

19. B. The Binomial System 2. Carolus Linnaeus (1701-1778) developed binomial system to name species. . First part is the genus; closely related species are assigned to the same genus.

20.             b. Second part is the specific epithet; it usually provides something descriptive about an organism.             c. A scientific name consists of both genus and specific epithet (e.g., Lilium/buibiferum and Liliumcanadense).             d. Both names are italicized or underlined; the first letter of only the genus name is capitalized.             e. The genus can be abbreviated when used with a specific epithet if the full name was given before.

21. C. What Is a Species? 2. The biological definition of a species states a species can interbreed and share the same gene pool.

22. A. Systematics is the study of the diversity of organisms using information from cellular to population levels         2. Phylogeny is the evolutionary history of a group of organisms.

23. C. Homology         1. Homology is a character similarity due to having a common ancestry.

24. 20.4. Classification Systems

25. A. Naming the Kingdoms         1. Early biologists recognized two kingdoms: animals (kingdom Animalia) and plants (kingdom Plantae).

26. B. Three-Domain System • Recent research suggests one group of prokaryotes is so distantly related it should be in separate domain • 2. Sequencing of rRNA suggests all organisms evolved along three distinct lineages: domains Bacteria, Archaea, and Eukarya.