When.com Web Search

  1. Ad

    related to: apush period 4 timeline quizlet biology

Search results

  1. Results From The WOW.Com Content Network
  2. AP United States History - Wikipedia

    en.wikipedia.org/wiki/AP_United_States_History

    There is a fifteen-minute reading period for students to read the essay prompts, take notes, and brainstorm, but students may begin to write the essays before this period ends. Students will then have 100 minutes to write the two essays; 60 minutes are recommended for the DBQ and 40 minutes for the long essay, but students are free to work on ...

  3. History of biology - Wikipedia

    en.wikipedia.org/wiki/History_of_biology

    The history of biology traces the study of the living world from ancient to modern times. Although the concept of biology as a single coherent field arose in the 19th century, the biological sciences emerged from traditions of medicine and natural history reaching back to Ayurveda, ancient Egyptian medicine and the works of Aristotle, Theophrastus and Galen in the ancient Greco-Roman world.

  4. Era - Wikipedia

    en.wikipedia.org/wiki/Era

    In large-scale natural science, there is need for another time perspective, independent from human activity, and indeed spanning a far longer period (mainly prehistoric), where "geologic era" refers to well-defined time spans. [13] The next-larger division of geologic time is the eon. [14] The Phanerozoic Eon, for example, is subdivided into ...

  5. Timeline of the evolutionary history of life - Wikipedia

    en.wikipedia.org/wiki/Timeline_of_the...

    At long irregular intervals, Earth's biosphere suffers a catastrophic die-off, a mass extinction, [9] often comprising an accumulation of smaller extinction events over a relatively brief period. [10] The first known mass extinction was the Great Oxidation Event 2.4 billion years ago, which killed most of the planet's obligate anaerobes.

  6. Timeline of natural history - Wikipedia

    en.wikipedia.org/wiki/Timeline_of_natural_history

    c. 2.58 Ma – start of the Pleistocene epoch, the Stone Age and the current Quaternary Period; emergence of the genus Homo. Smilodon, the best known of the sabre-toothed cats, appears. c. 2.4 Ma – The Amazon River takes its present shape in South America. c. 2.0–1.5 Ma – The basin of the Congo River acquires its present shape.

  7. Tree of life (biology) - Wikipedia

    en.wikipedia.org/wiki/Tree_of_life_(biology)

    Edward Hitchcock's fold-out paleontological chart in his 1840 Elementary Geology. Although tree-like diagrams have long been used to organise knowledge, and although branching diagrams known as claves ("keys") were omnipresent in eighteenth-century natural history, it appears that the earliest tree diagram of natural order was the 1801 "Arbre botanique" (Botanical Tree) of the French ...

  8. AP World History: Modern - Wikipedia

    en.wikipedia.org/wiki/AP_World_History:_Modern

    In 2012, the head of AP Grading, Trevor Packer, stated that the reason for the low percentages of 5s is that "AP World History is a college-level course, & many sophomores aren't yet writing at that level." 10.44 percent of all seniors who took the exam in 2012 received a 5, while just 6.62 percent of sophomores received a 5.

  9. Evolution of bacteria - Wikipedia

    en.wikipedia.org/wiki/Evolution_of_bacteria

    This suggests that an organism in of the phylum Thermotogota (formerly Thermotogae) [4] was the most recent common ancestor of modern bacteria. Further chemical and isotopic analysis of ancient rock reveals that by the Siderian period , roughly 2.45 billion years ago, [ 5 ] oxygen had appeared.