Question | Answer |
What is a fossil? | traces or imprints of once living things that are preserved in rock |
How are fossils formed? | organism dies, becomes buried under sediment, organism slowly decomposes leaving a mold in the sediment, over time mold fils in with sediment and forms a cast |
The scientists that study fossils are called? | Paleontologists |
What is half-life dating? | counting how much carbon -14 an object has (counting how quickly the carbon in an object goes down half the amount) |
What element is studied in half-life dating? | Carbon-14 |
Explain the differences between relative dating and absolute dating. | relative - comparing one object to another to see what might be older- might compare things found in different layers of the Earth - is less precise. Absolute - more accurate as it uses carbon-14 to help get a specific age on an object |
Are fossils found deep in the Earth older or younger? | The deeper down an object is found the older it is compared to objects found closer to the surface. |
List the four eras of the Earth. | Precambrian, Paleozoic, Mesozoic, Cenozoic |
What scale is used to define the Earth's long natural history and how does it work? | Geologic time scale - it helps scientists place fossils in chronological order so we can see how the Earth has changed over time. |
Define extinct. | no longer exists on Earth |
What types of organisms should be found in the Precambrian time? | singles celled organisms (prokaryotes) that didn't require oxygen to live |
What type of organisms should be found in the Paleozoic era? | sponges, corals, snails, clams, squids and trilobites |
What type of organisms should be found in the Mesozoic era? | dinosaurs, birds, lizards, conifer trees - later flowering plants |
What type of organisms should be found in the Cenozoic era? | mammals, birds, insects, flowering plants |
Define what Pangea is. | the theory that all the Earth's continents were once a giant land mass |
The idea that explains large pieces of the Earth's surface layers moving is | plate tectonics |
Give the time frame of the Precambrian time | 4.6 billion years ago to 543 million years ago |
Give the time frame of the Paleozoic era | 543 million years ago to 248 million years ago |
Give the time frame of the Mesozoic era | 248 million years ago to 183 million years ago |
Give the time frame of the Cenozoic era | 65 million years ago to today |
Define a prokaryotic organism | organism that is single-celled; has no nucleus |
Define an eukaryotic organism | multi-celled organism - cells have nucleus |
What element is ozone made from? | oxygen |
What is the importance of ozone? | reduces radiation from the sun to the Earth |
Which era was mostly water with the change of breathing land organisms? | Paleozoic |
The era of reptiles is? | Mesozoic |
The main theory of the end of the Mesozoic era is | large meteor hits Earth, the dust and debris blocked the sun light from the Earth, causing plants to die which in turn caused many dinosaurs to die |
Humans belong to what family of primates? | hominids |
Explain the differences between humans and other primates - what sets us apart? | Our skeletal features, intelligence, back bone that allows us to walk up right. |
What is the advantage of the opposable thumb? | allows us to grip objects |
List the following from oldest humans to more modern humans: global hominids, homo sapiens, australopithecines, and neanderthals | Australopithecines, global hominids, neanderthals, homo sapiens |